Richter's transformation: Transforming the clinical landscape

Richter transformation (RT) represents an aggressive histological transformation from chronic lymphocytic leukaemia, most often to a large B cell lymphoma. It is characterised by chemo-resistance and subsequent short survival. Drug development has struggled over recent years in light of the aggressive kinetics of the disease, lack of pivotal registrational trials and relative rarity of the phenomenon. In this review we will highlight the diagnostic and therapeutic challenges of managing patients with RT as well as taking a look to the future therapeutic landscape. Highly active therapies developed across B cell malignancies are starting to impact this field, with T-cell activation therapies (CAR-T, bispecific antibodies), antibody-drug conjugates, and novel small molecule inhibitor combinations (e.g. BTKi-BCL2i) being actively studied. We will highlight the data supporting these developments and look to the studies to come to provide hope for patients suffering from this devastating disease.

Teaching Hardy-Weinberg Equilibrium using Population-Level Punnett Squares: Facilitating Calculation for Students with Math Anxiety

Hardy-Weinberg (HW) equilibrium and its accompanying equations are widely taught in introductory biology courses, but high math anxiety and low math proficiency have been suggested as two barriers to student success. Population-level Punnett squares have been presented as a potential tool for HW equilibrium, but actual data from classrooms have not yet validated their use. We used a quasi-experimental design to test the effectiveness of Punnett squares over 2 days of instruction in an introductory biology course. After 1 day of instruction, students who used Punnett squares outperformed those who learned the equations. After learning both methods, high math anxiety was predictive of Punnett square use, but only for students who learned equations first. Using Punnett squares also predicted increased calculation proficiency for high-anxiety students. Thus, teaching population Punnett squares as a calculation aid is likely to trigger less math anxiety and help level the playing field for students with high math anxiety. Learning Punnett squares before the equations was predictive of correct derivation of equations for a three-allele system. Thus, regardless of math anxiety, using Punnett squares before learning the equations seems to increase student understanding of equation derivation, enabling them to derive more complex equations on their own.

Performance in practice; exploring trainer and trainee experiences of user-designed formative assessment tools

INTRODUCTION

General Practice training in Ireland currently has various methods of formative assessment and feedback delivered to trainees. In 2018 the Irish College of General Practitioners commissioned the generation of two new user-designed formative feedback tools that would allow trainee feedback to drive learning. These tools became known as the Performance in Practice (PiP) tools.

AIMS

To explore the experiences of General Practice (GP) trainers and trainees having completed a pilot of using the PiP tools for 4 months.

METHODS

An explorative phenomenological approach was taken to understand the experiences of trainers and trainees. One to one interviews were conducted, and the transcripts analysed for themes and sub-theme via Template analysis.

RESULTS

User experiences focused on two main areas; educational value and acceptability. In relation to educational value, the PiP tools were seen as an improvement over established forms of formative feedback, as they were centred around the curriculum and therefore reflected the unique multifaceted requirements of an independently practising GP. Acceptability primarily focused around data governance and structures, as well as practical issues such as ease of software use.

CONCLUSIONS

Overall, the experience of using the PiP tools was positive for both trainers and trainees. Future plans to further explore implementation of the PiP tools have been significantly informed by this research.

Improved stability of long-duration sitting in spatial neglect after a single session of prism adaptation

Spatial neglect after right brain stroke affects balance, and improvements in sitting balance after prism adaptation have been demonstrated using short-duration center of pressure (CoP) data. We present long-duration (5 min) CoP and trunk muscles electromyography recordings of a 61-year-old man with left-sided spatial neglect, before and after a single session of prism adaptation. His CoP-derived measures showed improved balance and postural stability in both the anterior-posterior and medial-lateral directions after prism adaptation. Concurrently, asymmetry in neuromuscular activations was reduced. The findings suggest that improved sitting balance may be associated with more symmetrical activation of trunk muscles after prism adaptation.

Thrombospondin-2 regulates extracellular matrix production, LOX levels, and cross-linking via downregulation of miR-29

Collagen fibrillogenesis and crosslinking have long been implicated in extracellular matrix (ECM)-dependent processes such as fibrosis and scarring. However, the extent to which matricellular proteins influence ECM protein production and fibrillar collagen crosslinking has yet to be determined. Here we show that thrombospondin 2 (TSP2), an anti-angiogenic matricellular protein, is an important modulator of ECM homeostasis. Specifically, through a fractionated quantitative proteomics approach, we show that loss of TSP2 leads to a unique ECM phenotype characterized by a significant decrease in fibrillar collagen, matricellular, and structural ECM protein production in the skin of TSP2 KO mice. Additionally, TSP2 KO skin displays decreased lysyl oxidase (LOX), which manifests as an increase in fibrillar collagen solubility and decreased levels of LOX-mediated fibrillar collagen crosslinking. We show that these changes are indirectly mediated by miR-29, a major regulator of ECM proteins and LOX, as miR-29 expression is increased in the TSP2 KO. Altogether, these findings indicate that TSP2 contributes to ECM production and assembly by regulating miR-29 and LOX.

Abstract PD9-09: Proteomic analysis of extracellular matrix helps define drivers of metastatic progression

Tumor microenvironment (TME) plays a central role in the development of distant metastasis. However, given its complexity, successful targeting of TME will require a detailed understanding of its composition. Cancer-associated fibroblasts represent a large component of TME and are a major contributor to the extracellular matrix (ECM). Previously, we demonstrated the presence of two fibroblast sub-populations (CDCP1pos vs CD146pos fibroblasts) in breast cancer TME, which determine therapeutic response in estrogen receptor (ER) positive breast cancer. We hypothesized that the same fibroblast subtypes would also influence ECM composition and alter the metastatic potential of breast cancer cells. Here, we present the development of a novel fibroblast driven orthotopic model of ER+ breast cancer metastasis, which we combined with an innovative proteomics approach to precisely quantify extracellular matrix proteins.

Results: 1.CDCP1pos fibroblasts promote increased breast cancer cell mobility, invasion and metastasis compared to CD146pos fibroblasts.We demonstrate that CDCP1pos fibroblasts significantly increase the invasion potential of breast cancer cells, when compared to CD146pos fibroblasts. Orthotopic co-implantation of ER+ tumor cells with CDCP1pos fibroblasts into the mammary fat pad of mice more frequently drives distant organ metastases to lung and brain when compared with tumors implanted with CD146pos fibroblasts. 2. Proteomic analysis of ER+ tumors influenced by CDCP1pos fibroblasts revealed known and novel drivers of breast cancer metastasis. Breast cancer cells mixed with CDCP1pos fibroblasts produce a non-uniform collagen orientation to the tumor boarder. Our novel proteomic analysis of TME specific proteins revealed that tumors influenced by CDCP1pos fibroblasts have high expression of many ECM proteins linked to increased risk of breast cancer metastasis, including TNC, FN1, COL5A3, and FBN1 among others. Derived proteomic TME signature accurately predicted lymph node involvement in patients who presented with early stage (T0 and T1) tumors in a cohort of 1,009 breast cancer patients from Cancer Genome Atlas Database. 3. Inhibiting fibroblast production of Tenascin C (TNC) results in decreased breast cancer cell invasion. Our in vitro mixed co-culture models, which contain ER+ breast cancer cells with both fibroblast subtypes, demonstrate that only CDCP1pos fibroblasts produce TNC. Furthermore, in spheroid assays with CDCP1posfibroblasts and breast cancer tumor cells, invasion is inhibited by TNC knockdown. The invasion phenotype can be rescued by addition of EGF, which suggests TNC promotes invasion via EGFR signaling.

Conclusion: Metastatic spread of cancer cells relies heavily on TME alterations and makeup of the extracellular matrix. Our data suggest that fibroblast composition directly influences ECM properties and metastatic potential in breast cancer. Taken together, we believe that a better understanding of ECM composition will lead to a more personalized approach to breast cancer treatment.

Citation Format: Brechbuhl HM, Barrett AS, Kopin E, Gillen A, Hagen J, Johnson L, Finaly-Shultz J, Sartorius CA, Hansen KC, Kabos P. Proteomic analysis of extracellular matrix helps define drivers of metastatic progression [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD9-09.

Malnutrition in Hospitalised Older Adults: A Multicentre Observational Study of Prevalence, Associations and Outcomes

BACKGROUND

Malnutrition is common in older adults and is associated with high costs and adverse outcomes. The prevalence, predictors and outcomes of malnutrition on admission to hospital are not clear for this population.

DESIGN

Prospective Cohort Study.

SETTING

Six hospital sites (five public, one private).

PARTICIPANTS

In total, 606 older adults aged 70+ were included. All elective and acute admissions to any speciality were eligible. Day-case admissions and those moribund on admission were excluded.

MEASUREMENTS

Socio-demographic and clinical data, including nutritional status (Mini-Nutritional Assessment - short form), was collected within 36 hours of admission. Outcome data was collected prospectively on length of stay, in-hospital mortality and new institutionalisation.

RESULTS

The mean age was 79.7; 51% were female; 29% were elective admissions; 67% were admitted to a medical specialty. Nutrition scores were available for 602/606; 37% had a 'normal' status, 45% were 'at-risk', and 18% were 'malnourished'. Malnutrition was more common in females, acute admissions, older patients and those who were widowed/ separated. Dementia, functional dependency, comorbidity and frailty independently predicted a) malnutrition and b) being at-risk of malnutrition, compared to normal status (p < .001). Malnutrition was associated with outcomes including an increased length of stay (p < .001), new institutionalisation (p =<0.001) and in-hospital mortality (p < .001).

CONCLUSIONS

These findings support the prioritisation of nutritional screening in clinical practice and public health policy, for all patients ≥70 on admission to hospital, and in particular for people with dementia, increased functional dependency and/or multi-morbidity, and those who are frail.

Pre-hospital notification is associated with improved stroke thrombolysis timing

Intravenous thrombolysis increases disability-free survival after acute ischaemic stroke in a time-dependent fashion. We aimed to determine whether pre-hospital notification, introduction of a CT scanner near to assessment site and introduction of out-of-hours thrombolysis services affect thrombolysis timing. Methods Timings related to thrombolysis were collected between May 2012 and June 2014 at a single hospital site; these included time to stroke physician assessment, time to cranial CT imaging and door to needle time. All thrombolysed ischaemic stroke patients admitted via the emergency department were included. Ambulance services were asked to pre-notify the emergency department of any suspected stroke patient during this period. Results We studied 182 patients (48% female; mean age 74 years; 59% pre-notified). Pre-hospital notification was associated with a significantly higher rate of CT scanning within 25 minutes (60% vs 24%, odds ratio [OR] 4.7, 95% confidence interval [CI] 2.4-9.0; p<0.001), earlier stroke physician assessment (median 6 vs 32 minutes; p<0.001) and receiving thrombolysis within 60 minutes (89% vs 49%, OR 8.0, 95% CI 3.8-16.9; p<0.001). Being treated outside normal working hours did not alter thrombolysis timing. Logistic regression identified the introduction of a near-site CT scanner (OR 4.6 [95% CI 1.7-12.5]) and pre-hospital notification (OR 4.7, [95% CI 2.3-9.6]) as independent predictors of door to CT time less than or equal to 25 minutes, and pre-hospital notification (OR 11.6, [95% CI 4.9-30.3]) and stroke severity (OR 1.15 per point of NIHSS scale, [95% CI 1.08-1.23]) as predictors of door to thrombolysis time less than or equal to 60 minutes. The most common perceived timing delays were radiology-related (33%), the need to acutely lower blood pressure (15%) and obtaining consent (12%). Conclusion Pre-hospital notification is associated with earlier stroke physician review, CT imaging and delivery of thrombolysis. Referral to an out of hours thrombolysis service was not associated with additional delay.

The wealth, health and wellbeing of Ireland's older people before and during the economic crisis

The economic crisis of 2008/9 was felt more acutely in Ireland relative to elsewhere and culminated in the international bailout in 2010. Given the economic collapse, Ireland provides an ideal case-study of the link between wealth collapses and movements in variables such as health and well-being. Using nationally-representative samples of older people collected before and during the crisis, we show that mean net assets fell by 45 percent between 2006/7 and 2012/13. In spite of this massive fall in wealth, measures of health and well-being remained broadly unchanged. However, expectations about future living standards became less optimistic. The results tend to support the findings of other recent studies that recessions do not have widespread negative effects on health and well-being.

Prasugrel compared to clopidogrel in patients with acute coronary syndrome undergoing percutenaous coronary intervention: a Spanish model-based cost effectiveness analysis

OBJECTIVE

To assess the long-term cost-effectiveness of 12 months treatment of prasugrel compared to clopidogrel in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) in the Spanish health care system.

METHODS

A Markov state transition model was developed to estimate health outcomes, quality adjusted life years (QALYs), life years (LY), and costs over patients' lifetimes. Clinical inputs were based on an analysis of the TRITON-TIMI 38 clinical trial. Hospital readmissions captured during the trial in a sub-study of patients from eight countries (and subsequent re-hospitalisations modelled to accrue beyond the time horizon of the trial), were assigned to Spanish diagnosis-related group payment schedules to estimate hospitalisation costs.

RESULTS

Mean total treatment costs were ?11,427 and ?10,910 for prasugrel and clopidogrel respectively. The mean cost of the study drug was ?538 higher for prasugrel vs. clopidogrel, but rehospitalisation costs at 12 months were ?79 lower for prasugrel due to reduced rates of revascularisation. Hospitalisation costs beyond 12 months were higher with prasugrel by ?55, due to longer life expectancy (+0.071 LY and +0.054 QALYs) associated with the decreased nonfatal myocardial infarction rate in the prasugrel group. The incremental cost per life year and QALY gained with prasugrel was ?7,198, and ?9,489, respectively.

CONCLUSION

Considering a willingness-to-pay threshold of ?30,000/QALY gained in the Spanish setting, prasugrel represents a cost-effective option in comparison with clopidogrel among patients with ACS undergoing PCI.

Bulky mediastinal Hodgkin's disease management and prognosis

Of a total of 235 Stage I and II Hodgkin's disease patients treated between 1970 and 1979, 103 (43.8 per cent) had mediastinal involvement in 45 of whom the disease was bulky and in 58 non-bulky. This report concentrates on bulky disease patients of whom 45 per cent did not relapse after therapy and 71 per cent are alive. Patients with mediastinal disease were treated with radiotherapy (63), sequential chemo-radiotherapy (37) or chemotherapy alone (3). In the radiotherapy group the relapse rate for bulky disease was significantly higher (65 per cent) than for non-bulky disease (44 per cent) (P less than 0.05) although there was no significant difference in survival. Neither relapse rate nor survival differed significantly in bulky disease patients treated with radiotherapy compared with combined chemo-radiotherapy although there was a 20 per cent difference in relapse-free survival rate in favour of the combined treatment group at five years. Treatments were not allocated randomly and the chemo-radiotherapy group contained a disproportionate number of patients with adverse features (greater than 3 node areas involved, limited lung extension) compared with the irradiated group; 11/25 and 2/17 respectively. The number of lymph node areas involved appeared to influence the relapse rate in the radiotherapy group. There was no correlation between mediastinal mass size and number of node areas involved suggesting that these two features may be independent prognostic factors.

Assessment of the regional economic impacts of catastrophic events: CGE analysis of resource loss and behavioral effects of an RDD attack scenario

We investigate the regional economic consequences of a hypothetical catastrophic event-attack via radiological dispersal device (RDD)-centered on the downtown Los Angeles area. We distinguish two routes via which such an event might affect regional economic activity: (i) reduction in effective resource supply (the resource loss effect) and (ii) shifts in the perceptions of economic agents (the behavioral effect). The resource loss effect relates to the physical destructiveness of the event, while the behavioral effect relates to changes in fear and risk perception. Both affect the size of the regional economy. RDD detonation causes little capital damage and few casualties, but generates substantial short-run resource loss via business interruption. Changes in fear and risk perception increase the supply cost of resources to the affected region, while simultaneously reducing demand for goods produced in the region. We use results from a nationwide survey, tailored to our RDD scenario, to inform our model values for behavioral effects. Survey results, supplemented by findings from previous research on stigmatized asset values, suggest that in the region affected by the RDD, households may require higher wages, investors may require higher returns, and customers may require price discounts. We show that because behavioral effects may have lingering long-term deleterious impacts on both the supply-cost of resources to a region and willingness to pay for regional output, they can generate changes in regional gross domestic product (GDP) much greater than those generated by resource loss effects. Implications for policies that have the potential to mitigate these effects are discussed.

Effects of teriparatide in postmenopausal women with osteoporosis pre-treated with bisphosphonates: 36-month results from the European Forsteo Observational Study

OBJECTIVES

To describe fracture rates, back pain, and health-related quality of life (HRQoL) in postmenopausal women with osteoporosis and prior bisphosphonate therapy, treated with teriparatide for up to 18 months and followed up for a further 18 months.

DESIGN

Prospective, multinational, and observational study.

METHODS

Data on prior bisphosphonate use, clinical fractures, back pain visual analog scale (VAS), and HRQoL (EQ-5D) were collected over 36 months. Fracture data were summarized in 6-month intervals and analyzed using logistic regression with repeated measures. Changes from baseline in back pain VAS and EQ-VAS were analyzed using a repeated measures model.

RESULTS

Of the 1581 enrolled patients with follow-up data, 1161 (73.4%) had a history of prior bisphosphonate use (median duration: 36 months). Of them, 169 (14.6%) sustained ≥1 fracture during 36-month follow-up. Adjusted odds of fracture were significantly decreased at each 6-month interval compared with the first 6 months of teriparatide treatment: 37% decrease in the 12 to <18 months period during teriparatide treatment (P=0.03) and a 76% decrease in the 12- to 18-month period after teriparatide was discontinued (P<0.001). Significant reductions in back pain and improvement in HRQoL were observed.

CONCLUSIONS

Postmenopausal women with severe osteoporosis previously treated with bisphosphonates had a significant reduction in the incidence of fractures compared with the first 6 months of therapy, a reduction in back pain and an improvement in HRQoL during up to 18 months of teriparatide treatment. These outcomes were still evident for at least 18 months after teriparatide was discontinued. The results should be interpreted in the context of an uncontrolled, observational study in a routine clinical setting.

Molecular-based mycobacterial identification in a clinical laboratory setting: a comparison of two methods

Many mycobacterial species are pathogenic to humans, with infection occurring worldwide. Infection with Mycobacterium tuberculosis is a well-described global phenomenon, but other mycobacterial species are increasingly shown to be the cause of both pulmonary and extrapulmonary infection and are managed differently from M. tuberculosis infection. Rapid and accurate differentiation of mycobacterial species is, therefore, critical to guide timely and appropriate therapeutic and public health management. This study evaluates two commercially available DNA strip assays, the Genotype Common Mycobacteria (CM) assay (Hain Lifescience, Nehren, Germany) and the Speed-oligo Mycobacteria assay (Vircell, Spain) for their usefulness in a clinical laboratory setting. Both assays were evaluated on 71 clinical mycobacterial isolates, previously identified using Gen-Probe AccuProbe and through a UK mycobacteriology reference laboratory, as well as 29 non-mycobacterial isolates. Concordant results were obtained for 98% of isolates using both assays. The sensitivity was 97% (95% confidence interval [CI]: 93.3-100%) for the CM assay and 98.6% (95% CI: 95.9-100%) for the Speed-oligo assay. Overall, both assays proved to be useful tools for rapid and sensitive mycobacterial species identification, although interpretation of results was easier with the CM assay. Finally, results were available within one day, compared to current identification times which range between seven days and four weeks.

Fracture rate and back pain during and after discontinuation of teriparatide: 36-month data from the European Forsteo Observational Study (EFOS)

In this observational study in postmenopausal women with severe osteoporosis, the incidence of fractures was decreased during 18 months of teriparatide treatment with no evidence of further change in the subsequent 18-month post-teriparatide period when most patients took other osteoporosis medications. Fracture reduction was accompanied by reductions in back pain.

INTRODUCTION

To describe fracture outcomes and back pain in postmenopausal women with severe osteoporosis during 18 months of teriparatide treatment and 18 months post-teriparatide in normal clinical practice.

METHODS

The European Forsteo Observational Study (EFOS) was a prospective, multinational, observational study. Data on incident clinical fractures and back pain (100 mm Visual Analogue Scale [VAS] and questionnaire) were collected. Fracture data were summarised in 6-month intervals and analysed using logistic regression with repeated measures. Changes from baseline in back pain VAS were analysed using a repeated measures model.

RESULTS

A total of 208 (13.2%) of 1,576 patients sustained 258 fractures during 36 months of follow-up: 34% were clinical vertebral fractures and 66% non-vertebral fractures. The adjusted odds of fracture were reduced during teriparatide treatment and there was no evidence of further change in the 18-month post-teriparatide period, during which 63.3% patients took bisphosphonates. A 74% decrease in the adjusted odds of fracture in the 30- to <36-month period compared with the first 6-month period was observed (p < 0.001). Back pain decreased during teriparatide treatment and this decrease was sustained after teriparatide discontinuation. Adjusted mean back pain VAS decreased by 26.3 mm after 36 months (p < 0.001) from baseline mean of 57.8 mm.

CONCLUSIONS

In a real-life clinical setting, the risk of fracture decreased during teriparatide treatment, with no evidence of further change after teriparatide was discontinued. The changes in back pain seen during treatment were maintained for at least 18 months after teriparatide discontinuation. These results should be interpreted in the context of the design of an observational study.

Molecular epidemiology of Mycobacterium tuberculosis in East Lancashire 2001-2009

BACKGROUND

East Lancashire has had high rates of tuberculosis for 40 years. The ethnically diverse population is predominantly of South Asian and white origin. Drug resistance data from 1960 to 1999 indirectly suggest that no significant inter-ethnic transmission has occurred. This study used mycobacterial interspersed repetitive unit variable number tandem repeat (MIRU-VNTR) fingerprinting to assess clustering within and between ethnic groups.

METHODS

All isolates of Mycobacterium tuberculosis from January 2001 to July 2009 from East Lancashire postcode areas were MIRU-VNTR fingerprinted. Clusters of strains with indistinguishable profiles were also assessed epidemiologically, and their MIRU-VNTR profiles compared with the UK M tuberculosis Strain Typing Database.

RESULTS

332 strains were typed (63 white patients, and 269 non-white patients). 198 MIRU-VNTR profiles were identified, with 144 profiles occurring only once. The typing clustered 187 strains into 53 clusters indistinguishable at all 12 loci and these were further characterised using the exact tandem repeat loci A, B, and C. The 15 loci clustered 32/63 (50.8%) of white and 110/269 (40.9%) of non-white cases and all but nine clusters were of the same ethnicity. The nine inter-racial clusters were further assessed from an epidemiological and clinical perspective and fingerprinting using nine additional loci. Isolates within two of the clusters were further discriminated using the additional nine loci. However, the additional loci did not further discriminate the isolates in the other seven inter-racial clusters.

CONCLUSIONS

MIRU-VNTR fingerprinting indicates that although there is evidence of a high rate of transmission within the South Asian sub-population, the data suggest that there is little inter-ethnic transmission.

Assessing the effect of foreign travel and protection by BCG vaccination on the spread of tuberculosis in a low incidence country, United Kingdom, October 2008 to December 2009

Binary file ES_Abstracts_Final_ECDC.txt matches

Assessing the effect of foreign travel and protection by BCG vaccination on the spread of tuberculosis in a low incidence country, United Kingdom, October 2008 to December 2009

The contribution of travel to high incidence countries and the impact of the discontinuation of universal Bacillus Calmette–Guérin (BCG) vaccination to there cent rise in tuberculosis (TB) in the United Kingdom remain unclear. An outbreak in a college presented an opportunity to assess these. A cohort of students answered a questionnaire assessing risk factors for TB.Participants were screened with an interferon gamma release assay (IGRA). Unadjusted and adjusted odds ratios (OR) were calculated using logistic regression.Among 2,284 students, 400 (17.5%) were diagnosed with TB infection. A higher risk was noted for travel to a high incidence area in the past two years (OR: 1.39;95% confidence interval (CI): 1.04–1.89) and among those with the greatest exposure to the index case(OR: 3.94; 95% CI: 2.60–5.97). There was no association between BCG and risk of infection (OR: 1.05; 95%CI: 0.80–1.39). The lack of a protective effect by BCG on TB infection supports the discontinuation of universal vaccination. The association with foreign travel suggests the need to assess the cost-effectiveness of serial IGRA testing and treatment of positive persons among returning travellers.

New aids for the non-invasive prenatal diagnosis of achondroplasia: dysmorphic features, charts of fetal size and molecular confirmation using cell-free fetal DNA in maternal plasma

OBJECTIVES

To improve the prenatal diagnosis of achondroplasia by constructing charts of fetal size, defining frequency of sonographic features and exploring the role of non-invasive molecular diagnosis based on cell-free fetal deoxyribonucleic acid (DNA) in maternal plasma.

METHODS

Data on fetuses with a confirmed diagnosis of achondroplasia were obtained from our databases, records reviewed, sonographic features and measurements determined and charts of fetal size constructed using the LMS (lambda-mu-sigma) method and compared with charts used in normal pregnancies. Cases referred to our regional genetics laboratory for molecular diagnosis using cell-free fetal DNA were identified and results reviewed.

RESULTS

Twenty-six cases were scanned in our unit. Fetal size charts showed that femur length was usually on or below the 3(rd) centile by 25 weeks' gestation, and always below the 3(rd) by 30 weeks. Head circumference was above the 50(th) centile, increasing to above the 95(th) when compared with normal for the majority of fetuses. The abdominal circumference was also increased but to a lesser extent. Commonly reported sonographic features were bowing of the femora, frontal bossing, short fingers, a small chest and polyhydramnios. Analysis of cell-free fetal DNA in six pregnancies confirmed the presence of the c.1138G > A mutation in the FGRF3 gene in four cases with achondroplasia, but not the two subsequently found to be growth restricted.

CONCLUSIONS

These data should improve the accuracy of diagnosis of achondroplasia based on sonographic findings, and have implications for targeted molecular confirmation that can reliably and safely be carried out using cell-free fetal DNA.

Global microRNA expression profiles in insulin target tissues in a spontaneous rat model of type 2 diabetes

AIMS/HYPOTHESIS

MicroRNAs regulate a broad range of biological mechanisms. To investigate the relationship between microRNA expression and type 2 diabetes, we compared global microRNA expression in insulin target tissues from three inbred rat strains that differ in diabetes susceptibility.

METHODS

Using microarrays, we measured the expression of 283 microRNAs in adipose, liver and muscle tissue from hyperglycaemic (Goto-Kakizaki), intermediate glycaemic (Wistar Kyoto) and normoglycaemic (Brown Norway) rats (n = 5 for each strain). Expression was compared across strains and validated using quantitative RT-PCR. Furthermore, microRNA expression variation in adipose tissue was investigated in 3T3-L1 adipocytes exposed to hyperglycaemic conditions.

RESULTS

We found 29 significantly differentiated microRNAs (p(adjusted) < 0.05): nine in adipose tissue, 18 in liver and two in muscle. Of these, five microRNAs had expression patterns that correlated with the strain-specific glycaemic phenotype. MiR-222 (p(adjusted) = 0.0005) and miR-27a (p(adjusted) = 0.006) were upregulated in adipose tissue; miR-195 (p(adjusted) = 0.006) and miR-103 (p(adjusted) = 0.04) were upregulated in liver; and miR-10b (p(adjusted) = 0.004) was downregulated in muscle. Exposure of 3T3-L1 adipocytes to increased glucose concentration upregulated the expression of miR-222 (p = 0.008), miR-27a (p = 0.02) and the previously reported miR-29a (p = 0.02). Predicted target genes of these differentially expressed microRNAs are involved in pathways relevant to type 2 diabetes.

CONCLUSION

The expression patterns of miR-222, miR-27a, miR-195, miR-103 and miR-10b varied with hyperglycaemia, suggesting a role for these microRNAs in the pathophysiology of type 2 diabetes, as modelled by the Gyoto-Kakizaki rat. We observed similar patterns of expression of miR-222, miR-27a and miR-29a in adipocytes as a response to increased glucose levels, which supports our hypothesis that altered expression of microRNAs accompanies primary events related to the pathogenesis of type 2 diabetes.

Planning Posttherapeutic Oncology Surveillance Visits Based on Individual Risk

The main objective of posttherapeutic surveillance in oncology is to detect recurrent disease associated with treatment failure. Current follow-up schedules are easy to apply because they are planned on a regular basis (for instance, every 3 months) but do not take into account prognostic factors associated with time to failure. We propose a 2-stage strategy to individualize surveillance by first identifying prognostic factors for time to failure, then modeling cumulative risk or cumulative incidence to plan visits according to equal quantiles of risk or probability of failure, respectively. Using data from a clinical trial of radiotherapy in non—small cell lung cancer patients, we demonstrate how this method could improve the early detection of relapse.

A footswitch evaluation of the gait of elderly fallers with and without a diagnosis of orthostatic hypotension and healthy elderly controls

Gait abnormalities are a recognised risk factor for falling in the elderly and variability in gait has been shown to be a measurable predictor of falls. We carried out a footswitch evaluation of the temporal parameters of gait of elderly fallers with a primary diagnosis of Orthostatic Hypotension, elderly fallers without a diagnosis of Orthostatic Hypotension and a control group of healthy elderly non-fallers. We hypothesized that elderly persons with Orthostatic Hypotension are falling purely as a consequence of their vascular abnormalities and are not falling for the same reasons as regular elderly fallers, including biomechanical irregularities. Therefore it was assumed that their gait pattern would not be similar to that of regular elderly fallers but instead would resemble that of healthy elderly non-fallers. Results show that elderly fallers with or without a diagnosis of Orthostatic Hypotension tend to spend more time in the stance phase of gait, possibly due to a fear of falling. Elderly fallers with a diagnosis of Orthostatic Hypotension have similar levels of gait variability as healthy elderly Controls. These are significantly less than elderly fallers without Orthostatic Hypotension. Therefore elderly fallers with a diagnosis of Orthostatic Hypotension may not be falling for the same reasons as regular elderly fallers.

Use of pharmacogenetic and clinical factors to predict the therapeutic dose of warfarin

Initiation of warfarin therapy using trial-and-error dosing is problematic. Our goal was to develop and validate a pharmacogenetic algorithm. In the derivation cohort of 1,015 participants, the independent predictors of therapeutic dose were: VKORC1 polymorphism -1639/3673 G>A (-28% per allele), body surface area (BSA) (+11% per 0.25 m(2)), CYP2C9(*)3 (-33% per allele), CYP2C9(*)2 (-19% per allele), age (-7% per decade), target international normalized ratio (INR) (+11% per 0.5 unit increase), amiodarone use (-22%), smoker status (+10%), race (-9%), and current thrombosis (+7%). This pharmacogenetic equation explained 53-54% of the variability in the warfarin dose in the derivation and validation (N= 292) cohorts. For comparison, a clinical equation explained only 17-22% of the dose variability (P < 0.001). In the validation cohort, we prospectively used the pharmacogenetic-dosing algorithm in patients initiating warfarin therapy, two of whom had a major hemorrhage. To facilitate use of these pharmacogenetic and clinical algorithms, we developed a nonprofit website, http://www.WarfarinDosing.org.

Prevalence and clinical characteristics of maternally inherited diabetes and deafness caused by the mt3243A > G mutation in young adult diabetic subjects in Sri Lanka

AIMS

The maternally inherited mt3243A > G mutation is associated with a variable clinical phenotype including diabetes and deafness (MIDD). We aimed to determine the prevalence and clinical characteristics of MIDD in a large South Asian cohort of young adult-onset diabetic patients from Sri Lanka.

METHODS

DNA was available from 994 subjects (age of diagnosis 16-40 years, age at recruitment < or = 45 years). Mutation screening was performed using a QRT-PCR method on an ABI 7900HT system using sequence-specific probes. Samples with heteroplasm > or = 5.0% were considered positive.

RESULTS

Nine (four males) mutation-positive subjects were identified (prevalence 0.9%). They were diagnosed at a younger age (25.9 +/- 4.8 years vs. 31.9 +/- 5.6 years, P = 0.002) and were lean (body mass index [BMI] 18.7 +/- 2.7 kg/m(2) vs. 24.7 +/- 4.0 kg/m(2), P < 0.001) compared to NMCs. One mutation-positive subject (11.1%) had metabolic syndrome, compared to 633 (64.3%) of NMCs. Insulin therapy within 6 months of diagnosis was used in four (44.0%) carriers compared to 6.9% of NMCs (P = 0.002). Combined screening criteria of any two of maternal history of diabetes, personal history of hearing impairment and family history of hearing impairment only identified five (55%) of the carriers, with a positive predictive value of 7.4%.

CONCLUSIONS

The prevalence of mt3243A > G mutation among young adult-onset diabetic subjects from Sri Lanka was 0.9%. Our study demonstrates that a maternal family history of diabetes and either a personal and/or family history of deafness only distinguish half of patients with MIDD from Sri Lankan subjects with young-onset diabetes.