Preoperative biliary drainage in patients performing pancreaticoduodenectomy : guidelines and real-life practice

BACKGROUND AND AIM

Preoperative biliary drainage (PBD) in patients with pancreatic cancer remains debatable. The aim of this study was to analyse the indications for PBD in patients performing pancreaticoduodenectomy (PD) and to evaluate the impact of this procedure on postoperative outcome.

METHODS

Observational retrospective cohort study of patients undergoing PD for pancreatic cancer. Clinical data and postoperative outcome, namely complications and 90-day mortality, were prospectively collected and compared between patients performing PBD or direct surgery (DS).

RESULTS

Eighty-two patients were included: 40 underwent PBD and 42 performed DS. Major complications (27.5% vs 33.3%, P=0.156) and 90-day mortality (10% vs 16.7%, P=0.376) were similar between the two groups. There was a trend for higher mean total bilirubin in patients with PBD (P=0.073). The indication for PBD was suspicion of cholangitis/choledocholithiasis or need to perform neoadjuvant chemotherapy in 24 (60%) patients. In the remaining, elevated bilirubin was probably the only reason to perform PBD. Length of hospital stay was longer in PBD group (P=0.003). On multiple logistic regression, 90-day mortality was not related with preoperative bilirubin levels, biliary drainage or its indication, but solely with age (OR 1.15, 95%CI 1.05-1.31, P=0.008).

CONCLUSIONS

PBD is often performed in patients undergoing PD without a formal indication, mainly due to high bilirubin levels. No increased morbidity/mortality was observed but length of hospital stay was prolonged in patients performing PBD.

TGFβi is involved in the chondrogenic differentiation of mesenchymal stem cells and is dysregulated in osteoarthritis

OBJECTIVE

Transforming growth factor-β (TGFβ) is a major regulator of cartilage homeostasis and its deregulation has been associated with osteoarthritis (OA). Deregulation of the TGFβ pathway in mesenchymal stem cells (MSCs) has been proposed to be at the onset of OA. Using a secretome analysis, we identified a member of the TGFβ family, TGFβ-induced protein (TGFβi or βIGH3), expressed in MSCs and we investigated its function and regulation during OA.

DESIGN

Cartilage, bone, synovium, infrapatellar fat pad and bone marrow-MSCs were isolated from patients with OA or healthy subjects. Chondrogenesis of BM-MSCs was induced by TGFβ3 in micropellet culture. Expression of TGFβi was quantified by RT-qPCR, ELISA or immunohistochemistry. Role of TGFβi was investigated in gain and loss of function experiments in BM-MSCs and chondrocytes.

RESULTS

TGFβi was up-regulated in early stages of chondrogenesis and its knock-down in BM-MSCs resulted in the down-regulation of mature and hypertrophic chondrocyte markers. It likely occurred through the modulation of adhesion molecules including integrin (ITG)β1, ITGβ5 and N-cadherin. We also showed that TGFβi was upregulated in vitro in a model of OA chondrocytes, and its silencing enhanced the hypertrophic marker type X collagen. In addition, TGFβi was up-regulated in bone and cartilage from OA patients while its expression was reduced in BM-MSCs. Similar findings were observed in a murine model of OA.

CONCLUSIONS

Our results revealed a dual role of TGFβi during chondrogenesis and pointed its deregulation in OA joint tissues. Modulating TGFβi in BM-MSCs might be of interest in cartilage regenerative medicine.

Two auricular epithesis surgical cases retained by a custom titanium implant: result at four years

INTRODUCTION

This article aims at describing the four-year outcome of a surgical procedure implanting a patient specific epithesis system in two patients.

TECHNICAL NOTE

After virtual 3D reconstruction of the anatomy and mirroring of the healthy ear, the position of the three Locator^® attachments were optimized in the software to embed them as accurately as possible in the planned episthesis antihelix. The personalized plate bearing the three Locator^® implants was then manufactured. Ten osteosynthesis screws were placed around the abutments to ensure bone anchorage. Post-operative antibiotic therapy was prescribed for the duration of ten days. The episthesis was placed two months post-operatively. The follow-up for each patient was 65 and 57 months respectively with no complications to report.

CONCLUSION

3D planning assists the surgeon and eliminates several constraints related to the placement of bone implants. It assists the surgical procedure and improves both the aesthetics and functional result of the surgery.

Spin transfer torque driven higher-order propagating spin waves in nano-contact magnetic tunnel junctions

Short wavelength exchange-dominated propagating spin waves will enable magnonic devices to operate at higher frequencies and higher data transmission rates. While giant magnetoresistance (GMR)-based magnetic nanocontacts are efficient injectors of propagating spin waves, the generated wavelengths are 2.6 times the nano-contact diameter, and the electrical signal strength remains too weak for applications. Here we demonstrate nano-contact-based spin wave generation in magnetic tunnel junctions and observe large-frequency steps consistent with the hitherto ignored possibility of second- and third-order propagating spin waves with wavelengths of 120 and 74 nm, i.e., much smaller than the 150-nm nanocontact. Mutual synchronization is also observed on all three propagating modes. These higher-order propagating spin waves will enable magnonic devices to operate at much higher frequencies and greatly increase their transmission rates and spin wave propagating lengths, both proportional to the much higher group velocity.

Abstract 503: Modeling Premature Cardiac Aging by Induced Pluripotent Stem Cell From a Patient With Hutchinson-Gilford Progeria Syndrome

Background: Hutchinson-Gilford Progeria Syndrome (HGPS) is an extremely rare genetic disorder characterized by accelerated aging and high incidence of cardiovascular complications and metabolic alterations. However, the underlying mechanisms of this syndrome are not fully understood.

Methods and Results: This study modelled HGPS using cardiomyocytes generated from induced pluripotent stem cells (iPSc) derived from a patient affected by the syndrome, characterizing the molecular and biophysical alterations found in cardiomyocytes obtained from three distinct differentiation protocols run in parallel with a control iPSc. Electrophysiology recordings were performed with intracellular microelectrodes and the Progeria cardiomyocytes fired action potentials similar to those from control iPSc-derived cardiomyocytes. High resolution respirometry performed on Oroboros system in isolated cardiomyocytes showed that Progeria cardiomyocytes have a tendency to decrease the oxygen consumption under basal condition and after FCCP, when compared to control cardiomyocytes (P=0.06). Furthermore, HGPS cardiomyocytes produced less ROS under basal and after 100uM Hydrogen peroxide treatment. However, mitotracker analysis shows no difference on mitochondrial content. Electron tomography and 3D reconstruction analysis suggest structural abnormalities in the mitochondria of Progeria cardiomyocytes. Proteomics analysis, performed with Liquid Chromatography tandem mass spectrometry (LC-MS/MS) in a high-resolution system (Q-Exactive Plus, Thermo Fischer), shows differential protein expression between Progeria (183 unique proteins) and Control (225 unique proteins) IPSc - derived cardiomyocytes.

Conclusions: Our work demonstrate that iPSc- derived cardiomyocytes from Progeria patients have significant alterations in cellular respiration and protein expression.

Work on a quantum dipole by a single-photon pulse

Energy transfer from a quantized field to a quantized dipole is investigated. We find that a single photon can transfer energy to a two-level dipole by inducing a dynamic Stark shift, going beyond the well-known absorption and emission processes. A quantum thermodynamical perspective allows us to unravel these two energy transfer mechanisms and to identify the former as a generalized work and the latter as a generalized heat. We show two necessary conditions for the generalized work transfer by a single photon to occur, namely, off-resonance and finite linewidth of the pulse. We also show that the generalized work performed by a single-photon pulse equals the reactive (dispersive) contribution of the work performed by a semiclassical pulse in the low-excitation regime.

Natriuretic peptide system regulation in granulosa cells during follicle deviation and ovulation in cattle

Natriuretic peptides (NPs) are known to regulate reproductive events in polyovulatory species, but their function and regulation in monovulatory species remain to be fully characterized. Using a well-established in vivo model, we found that bovine granulosa cells from follicles near the deviation stage express mRNA for the three NP receptors (NPR1, NPR2 and NPR3), but not for NP precursors (NPPA, NPPB and NPPC). The abundance of NPR3 mRNA was higher in dominant compared to subordinate follicles at the expected time of follicular deviation. After deviation, mRNA for all NP receptors was significantly more abundant in the dominant follicle. Intrafollicular inhibition of oestrogen receptors downregulated NPR1 mRNA in dominant follicles. In granulosa cells from preovulatory follicles, NPPC mRNA increased at 3 and 6 h after systemic GnRH treatment, but decreased at 12 and 24 h to similar levels observed in samples collected at 0 h. After GnRH treatment, NPR1 mRNA was upregulated at 24 h, NPR3 mRNA gradually decreased after 3 h, while NPR2 mRNA was not regulated. The mRNA expression of the enzyme FURIN increased at 24 h after GnRH treatment. These findings revealed that the expression of mRNA encoding important components of the NP system is regulated in bovine granulosa cells during follicular deviation and in response to GnRH treatment, which suggests a role of NP system in the modulation of these processes in monovulatory species.

The incidence of bent dorsal fins in free-ranging cetaceans

Laterally bent dorsal fins are rarely observed in free-ranging populations of cetaceans, contrary to captivity, where most killer whale Orcinus orca adult males have laterally collapsed fins. This topic has been poorly explored, and data/information on its occurrence and possible causes are limited. The present study: (i) undertakes a review of the available information on bent dorsal fins in free-ranging cetaceans, and updates it with new records, (ii) reports on the proportion of bent fins in different study populations, and (iii) discusses possible causes. An empirical approach based on bibliographic research and compilation of 52 new records collected worldwide resulted in a total of 17 species of cetaceans displaying bent dorsal fins. The species with the highest number of records (64%) and from most locations was O. orca. On average, individuals with bent dorsal fins represent < 1% of their populations, with the exception of false killer whales Pseudorca crassidens and O. orca. While line injuries associated with fisheries interactions may be the main cause for P. crassidens, and the vulnerability to health issues caused by the evolutionary enlargement of the fin may be the cause for O. orca adult males, factors contributing to this abnormality for other species are still unclear. The occurrence of bent dorsals could be influenced by a set of variables rather than by a single factor but, irrespective of the cause, it is suggested that it does not directly affect the animals' survivorship. While still rare in nature, this incident is more common (at least 101 known cases) and widespread (geographically and in species diversity) than hypothesized, and is not confined only to animals in captive environments. Investigation into the occurrence of bent fins may be an interesting avenue of research.