Feasibility of monitoring peripheral blood to detect emerging clones in children with acute lymphoblastic leukemia†

Relapse‐enriched somatic variants drive drug resistance in childhood acute lymphoblastic leukemia. We used digital droplet‐based polymerase chain reaction to establish whether relapse‐enriched mutations in emerging subclones could be detected in peripheral blood samples before frank relapse. Although limitations in sensitivity for some probes hindered detection of certain variants, we successfully detected variants in NT5C2 and PRPS1 at a fractional abundance of 0.005% to 0.3%, 41 to 116 days before relapse. As mutations in both these genes confer resistance to thiopurines, early detection protocols using peripheral blood could be implemented to preemptively alter maintenance therapy to extinguish resistant clones before overt relapse.     

RNA-Seq analysis in an avian model of maternal phenylketonuria

Cardiac malformations (CVMs) are a leading cause of infant morbidity and mortality. CVMs are particularly prevalent when the developing fetus is exposed to high levels of phenylalanine in-utero in mothers with Phenylketonuria. Yet, elucidating the underlying molecular mechanism leading to CVMs has proven difficult. In this study we used RNA-Seq to investigate an avian model of MPKU and establish differential gene expression (DEG) characteristics of the early developmental stages HH10, 12, and 14. In total, we identified 633 significantly differentially expressed genes across stages HH10, 12, and 14. As expected, functional annotation of significant DEGs identified associations seen in clinical phenotypes of MPKU including CVMs, congenital heart defects, craniofacial anomalies, central nervous system defects, and growth anomalies. Additionally, there was an overrepresentation of genes involved in cardiac muscle contraction, adrenergic signaling in cardiomyocytes, migration, proliferation, metabolism, and cell survival. Strikingly, we identified significant changes in expression with multiple genes involved in Retinoic Acid (RA) metabolism and downstream targets. Using qRTPCR, we validated these findings and identified a total of 42 genes within the RA pathway that are differentially expressed. Here, we report the first elucidation of the molecular mechanisms of cardiovascular malformations in MPKU conducted at early developmental timepoints. We provide evidence suggesting a link between PHE exposure and the alteration of RA pathway. These results are promising and offer novel findings associated with congenital heart defects in MPKU.     

Surgical and pathologic outcomes of fertility-sparing radical abdominal trachelectomy for FIGO stage IB1 cervical cancer

ObjectivesTo describe the surgical and pathologic findings of fertility-sparing radical abdominal trachelectomy using a standardized surgical technique, and report the rate of post-trachelectomy adjuvant therapy that results in permanent sterility.MethodsA prospectively maintained database of all patients with FIGO stage IB1 cervical cancer admitted to the operating room for planned fertility-sparing radical abdominal trachelectomy was analyzed. Sentinel node mapping was performed via cervical injection of Technetium and blue dye.ResultsBetween 6/2005 and 5/2008, 22 consecutive patients with FIGO stage IB1 cervical cancer underwent laparotomy for planned fertility-sparing radical abdominal trachelectomy. Median age was 33 years (range, 23–43). Histology included 13 (59%) with adenocarcinoma and 9 (41%) with squamous carcinoma. Lymph-vascular invasion was seen in 9 (41%) cases. Only 3 (14%) needed immediate completion radical hysterectomy due to intraoperative findings (2 for positive nodes, 1 for positive endocervical margin). Median number of nodes evaluated was 23 (range, 11–44); and 6 (27%) patients had positive pelvic nodes on final pathology — all received postoperative chemoradiation. Sixteen (73%) patients agreed to participate in sentinel node mapping which yielded a detection rate of 100%, sensitivity of 83%, specificity of 100% and false-negative rate of 17%. Eighteen of 19 (95%) patients who completed trachelectomy had a cerclage placed, and 9/22 (41%) patients had no residual cervical carcinoma on final pathology. Median time in the operating room was 298 min (range, 180–425). Median estimated blood loss was 250 ml (range, 50–700), and median hospital stay was 4 days (range, 3–6). No recurrences were noted at the time of this report.ConclusionsCervical adenocarcinoma and lymph-vascular invasion are common features of patients selected for radical abdominal trachelectomy. The majority of patients can undergo the operation successfully; however, nearly 32% of all selected cases will require hysterectomy or postoperative chemoradiation for oncologic reasons. Sentinel node mapping is useful but until lower false-negative rates are achieved total lymphadenectomy remains the gold standard. Investigating alternative fertility-sparing adjuvant therapy in node positive patients is needed.     

Guided growth of neurons and glia using microfabricated patterns of parylene-C on a SiO2 background

This paper describes a simple technique for the patterning of glia and neurons. The integration of neuronal patterning to Multi-Electrode Arrays (MEAs), planar patch clamp and silicon based ‘lab on a chip’ technologies necessitates the development of a microfabrication-compatible method, which will be reliable and easy to implement. In this study a highly consistent, straightforward and cost effective cell patterning scheme has been developed. It is based on two common ingredients: the polymer parylene-C and horse serum. Parylene-C is deposited and photo-lithographically patterned on silicon oxide (SiO₂) surfaces. Subsequently, the patterns are activated via immersion in horse serum. Compared to non-activated controls, cells on the treated samples exhibited a significantly higher conformity to underlying parylene stripes. The immersion time of the patterns was reduced from 24 to 3 h without compromising the technique. X-ray photoelectron spectroscopy (XPS) analysis of parylene and SiO₂ surfaces before and after immersion in horse serum and gel based eluant analysis suggests that the quantity and conformation of proteins on the parylene and SiO₂ substrates might be responsible for inducing glial and neuronal patterning.     

Updating evidence-based clinical guidelines

OBJECTIVES: To report on the updating of two evidence-based guidelines. METHODS: Development of multi-disciplinary evidence-based guidelines within the North of England Evidence Based Guideline Development Programme. RESULTS: The guideline updating groups were multi-disciplinary although the balance of disciplines was different from the original development groups; the convening of the updating groups allowed refinement of both the skills within the groups and the overall size of the groups. As both groups were starting with a previous version of the guideline, defining the scope of the guideline was more straightforward and faster than when developing the guideline de novo. The process of evidence identification for both guidelines was again by systematic review. Updating the guidelines influenced recommendations in two ways: new evidence required new recommendations; and supplementary evidence in an existing area allowed refinement of recommendations. Overall savings within the guideline updating process (compared with initial development) were modest. The major costs of both the initial guideline development and the updating process were staff costs, which were identical for the two processes. CONCLUSIONS: There is little other experience to set alongside this paper. There is a need for further sharing of experiences and the development of explicit methods for informing decisions on when and how to update evidence-based guidelines.     

Troglitazone antagonizes metabolic effects of glucocorticoids in humans: effects on glucose tolerance,insulin sensitivity,suppression of free fatty acids,and leptin

Glucocorticoids induce insulin resistance in humans, whereas thiazolidinediones enhance insulin sensitivity. Although the effects of glucocorticoids and thiazolidinediones have been assessed in isolation, interaction between these drugs, which both act as ligands for nuclear receptors, has been less well studied. Therefore, we examined the metabolic effects of dexamethasone and troglitazone, alone and in combination, for the first time in humans. A total of 10 healthy individuals with normal glucose tolerance (age 40 +/- 11 years, BMI 31 +/- 6.1 kg/m(2)) were sequentially studied at baseline, after 4 days of dexamethasone (4 mg/day), after 4-6 weeks on troglitazone alone (400 mg/day), and again after 4 days of dexamethasone added to troglitazone. Key metabolic variables included glucose tolerance assessed by blood glucose and insulin responses to an oral glucose tolerance test (OGTT), insulin sensitivity evaluated via hyperinsulinemic-euglycemic clamp, free fatty acids (FFAs) and FFA suppressibility by insulin during the clamp study, and fasting serum leptin. Dexamethasone drastically impaired glucose tolerance, with fasting and 2-h OGTT insulin values increasing by 2.3-fold (P < 0.001) and 4.4-fold (P < 0.001) over baseline values, respectively. The glucocorticoid also induced a profound state of insulin resistance, with a 34% reduction in maximal glucose disposal rates (GDRs; P < 0.001). Troglitazone alone increased GDRs by 20% over baseline (P = 0.007) and completely prevented the deleterious effects of dexamethasone on glucose tolerance and insulin sensitivity, as illustrated by a return of OGTT glucose and insulin values and maximal GDR to near-baseline levels. Insulin-mediated FFA suppressibility (FFA decline at 30 min during clamp/FFA at time 0) was also markedly reduced by dexamethasone (P = 0.002). Troglitazone had no effect per se, but it was able to normalize FFA suppressibility in subjects coadministered dexamethasone. Futhermore, the magnitudes of response of FFA suppressibility and GDR to dexamethasone were proportionate. The same was true for the reversal of dexamethasone-induced insulin resistance by troglitazone, but not in response to troglitazone alone. Leptin levels were increased 2.2-fold above baseline by dexamethasone. Again, troglitazone had no effect per se but blocked the dexamethasone-induced increase in leptin. Subjects experienced a 1.7-kg weight gain while taking troglitazone but no other untoward effects. We conclude that in healthy humans, thiazolidinediones antagonize the action of dexamethasone with respect to multiple metabolic effects. Specifically, troglitazone reverses both glucocorticoid-induced insulin resistance and impairment of glucose tolerance, prevents dexamethasone from impairing the antilipolytic action of insulin, and blocks the increase in leptin levels induced by dexamethasone. Even though changes in FFA suppressibility were correlated with dexamethasone-induced insulin resistance and its reversal by troglitazone, a cause-and-effect relationship cannot be established. However, the data suggest that glucocorticoids and thiazolidinediones exert fundamentally antagonistic effects on human metabolism in both adipose and muscle tissues. By preventing or reversing insulin resistance, troglitazone may prove to be a valuable therapeutic agent in the difficult clinical task of controlling diabetes in patients receiving glucocorticoids.