Clonal hematopoiesis related TET2 loss-of-function impedes IL1β-mediated epigenetic reprogramming in hematopoietic stem and progenitor cells

Clonal hematopoiesis (CH) is defined as a single hematopoietic stem/progenitor cell (HSPC) gaining selective advantage over a broader range of HSPCs. When linked to somatic mutations in myeloid malignancy-associated genes, such as TET2-mediated clonal hematopoiesis of indeterminate potential or CHIP, it represents increased risk for hematological malignancies and cardiovascular disease. IL1β is elevated in patients with CHIP, however, its effect is not well understood. Here we show that IL1β promotes expansion of pro-inflammatory monocytes/macrophages, coinciding with a failure in the demethylation of lymphoid and erythroid lineage associated enhancers and transcription factor binding sites, in a mouse model of CHIP with hematopoietic-cell-specific deletion of Tet2. DNA-methylation is significantly lost in wild type HSPCs upon IL1β administration, which is resisted by Tet2-deficient HSPCs, and thus IL1β enhances the self-renewing ability of Tet2-deficient HSPCs by upregulating genes associated with self-renewal and by resisting demethylation of transcription factor binding sites related to terminal differentiation. Using aged mouse models and human progenitors, we demonstrate that targeting IL1 signaling could represent an early intervention strategy in preleukemic disorders. In summary, our results show that Tet2 is an important mediator of an IL1β-promoted epigenetic program to maintain the fine balance between self-renewal and lineage differentiation during hematopoiesis.

A pilot study to investigate the effect of topical microporous polysaccharide haemospheres on outcomes following robot-assisted radical prostatectomy

INTRODUCTION

Controlling bleeding without disturbing the anatomy and function of the structures in the prostate bed remains a significant challenge during radical prostatectomy (RP).

MATERIALS AND METHODS

Five grams of powdered microporous polysaccharide haemospheres (MPH) was applied to the prostate bed at the end of robot-assisted RP in 422 consecutive patients. Continence was defined as no pads and potency as the ability to have penetrative sex with or without PDE5 inhibitors in previously potent, non-diabetic men aged <70 years following bilateral intra- or inter-fascial neurovascular bundle (NVB) preservation.

RESULTS

In total, 95.3% of patients had nerve preservation and the mean operating time and blood loss were 142 minutes and 200ml, respectively. There were no intraoperative complications, and the postoperative transfusion rate was 0.2%. The mean hospital stay was 1.7 nights, and duration of catheterisation was 12 days. Final pathology demonstrated a mean prostate weight of 40.0g and 14.5% replacement by cancer, most commonly Gleason 7. The positive surgical margin rate for pT2 tumours was 10.0%. Biochemical recurrence was 2.1% at a mean follow-up of 18.0 months. Continence and potency rates at 4 weeks and 1 year after surgery were 76.4% and 97.7% and 27.8% and 78.1%, respectively. The trifecta and pentafecta rates 1 year after surgery were 53.1% and 45.8%.

DISCUSSION AND CONCLUSION

Powdered MPH applied to the prostate bed at the end of robot-assisted RP appears to be a safe, easily applied and useful adjunct to conventional haemostasis. The suggestion that it might also improve the functional outcomes of RP merits further investigation in the context of a randomised trial.

An integrated in vitro and in vivo high-throughput screen identifies treatment leads for ependymoma

Using a mouse model of ependymoma-a chemoresistant brain tumor-we combined multicell high-throughput screening (HTS), kinome-wide binding assays, and in vivo efficacy studies, to identify potential treatments with predicted toxicity against neural stem cells (NSC). We identified kinases within the insulin signaling pathway and centrosome cycle as regulators of ependymoma cell proliferation, and their corresponding inhibitors as potential therapies. FDA approved drugs not currently used to treat ependymoma were also identified that posses selective toxicity against ependymoma cells relative to normal NSCs both in vitro and in vivo, e.g., 5-fluorouracil. Our comprehensive approach advances understanding of the biology and treatment of ependymoma including the discovery of several treatment leads for immediate clinical translation.

Mutual mentoring in laparoscopic urology - a natural progression from laparoscopic fellowship

INTRODUCTION

The objective of this study is to report a novel system of 'mutual mentoring' that overcomes the limited availability of laparoscopic mentors and allows progression from laboratory and fellowship experience into independent clinical practice.

PATIENTS AND METHODS

A total of 88 laparoscopic cases were performed during the fellowship. In the first 2 years as consultants, we (AJ and MS) performed 151 cases with mutual mentoring (simple nephrectomy [n = 28], radical nephrectomy [n = 35], nephro-ureterectomy [n = 19], pyeloplasty [n = 31], pelvic LND [n = 21], others [n = 17]).

RESULTS

Mutual mentoring has resulted in the successful introduction of laparoscopic services to two hospitals, allowing an exposure to an average of two cases a week. Complication rates are acceptable and objective measures such as conversion rates, operative time and blood loss appear to be improving.

CONCLUSIONS

Mutual mentoring allows for a greater through-put of cases, a high level of assistance, advice with intra-operative decisions and the potential to 'share' cases, reducing fatigue and increasing experience. It provides significant moral support in the difficult early days of starting the service. Its disadvantages are that it is time consuming and is geographically restrictive. Mutual mentoring has allowed us to introduce a laparoscopic service at our respective hospitals with high case-load acceptable complication rates.

Break-up of the Atlantic deep western boundary current into eddies at 8° S

The existence in the ocean of deep western boundary currents, which connect the high-latitude regions where deep water is formed with upwelling regions as part of the global ocean circulation, was postulated more than 40 years ago. These ocean currents have been found adjacent to the continental slopes of all ocean basins, and have core depths between 1,500 and 4,000 m. In the Atlantic Ocean, the deep western boundary current is estimated to carry (10-40) x 10(6) m3 s(-1) of water, transporting North Atlantic Deep Water--from the overflow regions between Greenland and Scotland and from the Labrador Sea--into the South Atlantic and the Antarctic circumpolar current. Here we present direct velocity and water mass observations obtained in the period 2000 to 2003, as well as results from a numerical ocean circulation model, showing that the Atlantic deep western boundary current breaks up at 8 degrees S. Southward of this latitude, the transport of North Atlantic Deep Water into the South Atlantic Ocean is accomplished by migrating eddies, rather than by a continuous flow. Our model simulation indicates that the deep western boundary current breaks up into eddies at the present intensity of meridional overturning circulation. For weaker overturning, continuation as a stable, laminar boundary flow seems possible.

EXTRAPERITONEAL LAPAROSCOPIC PYELOPLASTY FOR PRIMARY AND SECONDARY URETEROPELVIC JUNCTION OBSTRUCTION

PURPOSE

Greater experience with urological laparoscopy has lead to increasing interest in its use for reconstructive surgery, such as pyeloplasty.

MATERIALS AND METHODS

A total of 124 cases of laparoscopic pyeloplasty were performed, of which 11 followed failed primary treatment done elsewhere, namely balloon dilation (3), endopyelotomy (3); open pyeloplasty (3), endopyelotomy plus balloon dilation (1) and open pyeloplasty plus balloon dilation (1). Nine patients had renal calculi. A 4 port, balloon dissecting, extraperitoneal laparoscopic approach was used in all except 1 patient, who had a horseshoe kidney, necessitating a transperitoneal approach.

RESULTS

Operative time was 29 minutes longer in the secondary pyeloplasty group compared to primary cases (173.3 vs 144.0 minutes) but the conversion rate (0% vs 1.6%) and duration of postoperative hospitalization (2.8 nights each) were no greater. The complication rate was 3.6% and 9.1%, respectively. The success rate was 98.2% and 90.9% (p = 0.63) at a mean followup of 20.2 and 19.7 months, respectively. In the 9 patients with renal calculi a total of 18 calculi (94.7%) were successfully removed and the ureter was transposed medial to a crossing vessel in 50.0%. Trainee operating did not significantly prolong the procedure vs no training (162.0 vs 143.9 minutes, p = 0.06).

CONCLUSIONS

Extraperitoneal laparoscopic dismembered pyeloplasty is capable of addressing all causes of ureteropelvic junction obstruction with excellent functional results and low morbidity, and with an operative time similar to that of open pyeloplasty. Secondary laparoscopic pyeloplasty does not increase hospitalization, conversion or complication rates.

Induction of biologically active interleukin-8 from lung epithelial cells by Burkholderia (Pseudomonas) cepacia products

The frequency of isolation of Burkholderia cepacia from the sputum of cystic fibrosis (CF) patients is increasing. Using the human A549 lung epithelial cell line, we have investigated the ability of B. cepacia exoproducts to stimulate interleukin-8 (IL-8) release. Cell-free supernatants from a panel of CF clinical, non-CF clinical, and nonclinical B. cepacia isolates were found to stimulate IL-8 release, with levels ranging from 11.8 +/- 2.8 to 80.0 +/- 3.5 ng/ml. A similar pattern was seen at the level of the IL-8 mRNA. The bioactivity of the IL-8 was confirmed by examining its effect on the intracellular free calcium in neutrophils and inhibition by a neutralizing anti-IL-8 antibody. B. cepacia lipopolysaccharide, which was able to stimulate IL-8 release from monocytes, did not release IL-8 from the A549 cells. Furthermore, the stimulating ability of the bacterial cell-free supernatant was not diminished by polymyxin B, was markedly reduced by boiling, and appeared unrelated to N-acylhomoserine lactones. The ability of B. cepacia to elicit IL-8 release from epithelial cells may be important in the pathology of CF.