In Situ Hypothermic Perfusion of the Liver for Complex Hepatic Resection: Surgical Refinements

INTRODUCTION

While total vascular exclusion (TVE) with veno-venous bypass and hypothermia may be undertaken to increase liver tolerance for complex liver resection, these procedures are still associated with elevated rates of postoperative complications and mortality. In particular, one of the main issues of this strategy is the management of bleeding after declamping, which is enhanced by both hypothermic state and acidosis. To overcome this high risk of morbidity, several technical refinements might be undertaken and here described (with video).

METHODS

All patients, requiring TVE >60 min and liver cooling during hepatectomy, were retrospectively included in this study. Technical key points as (a) patient selection, (b) anesthetic management, (c) two-surgeon's technique, (d) preparation for clamping, (e) veno-venous bypass, (f) cooling of the liver, and (g) parenchymal transection, rewarming, and declamping are described and detailed.

RESULTS

From 2011 to 2013, we included 8 cases of liver resection with TVE, veno-venous bypass, and hypothermia for malignant disease. Due to the technical refinements, median observed overall blood loss of 550 ml (300-900) including 200 ml (50-300) at declamping and transfusion of packed red blood cell (PRBC) units was required in 5 patients with a mean of 1.25 PRBC/patient.

CONCLUSION

The association of TVE, veno-venous bypass, and liver cooling can reduce the time of transection, and blue dye injection and liver rewarming before declamping can reduce blood loss and coagulopathy. Altogether, limited blood loss can be achieved for these complex procedures and may allow to decreasing morbidity.

Search for B^{+}→K^{+}τ^{+}τ^{-} at the BaBar Experiment

We search for the rare flavor-changing neutral current process B^{+}→K^{+}τ^{+}τ^{-} using data from the BABAR experiment. The data sample, collected at the center-of-mass energy of the ϒ(4S) resonance, corresponds to a total integrated luminosity of 424  fb^{-1} and to 471×10^{6}  BB[over ¯] pairs. We reconstruct one B meson, produced in the ϒ(4S)→B^{+}B^{-} decay, in one of many hadronic decay modes and search for activity compatible with a B^{+}→K^{+}τ^{+}τ^{-} decay in the rest of the event. Each τ lepton is required to decay leptonically into an electron or muon and neutrinos. Comparing the expected number of background events with the data sample after applying the selection criteria, we do not find evidence for a signal. The resulting upper limit, at the 90% confidence level, is B(B^{+}→K^{+}τ^{+}τ^{-})<2.25×10^{-3}.

Positive end-expiratory pressure does not decrease cardiac output during laparoscopic liver surgery: A prospective observational evaluation

BACKGROUND

Positive end-expiratory pressure (PEEP) has beneficial pulmonary effects but may worsen the hemodynamic repercussions induced by pneumoperitoneum (PNP) in patients undergoing laparoscopic liver resection. However, by increasing intraluminal vena cava (VC) pressures, PEEP may prevent PNP-induced VC collapse. The aim of this study was to test the validity of this hypothesis.

METHODS

After IRB approval and written informed consent, 20 patients were evaluated prospectively. Measurements were performed before and after the application of 10 cmH₂O PEEP on patients without PNP (Control group) and during a 12 cmH₂0 PNP. Results are provided as means [95%CI]. Comparison used paired-sample t test.

RESULTS

PEEP induced a decrease in CI in Control subgroup (2.3 [2.0-2.6] and 2.1 [1.8-2.4] l min^-1 m^-2 before and after PEEP. P < 0.05). In contrast, PEEP on a pre-established PNP did not significantly modify cardiac index (CI). Transmural pressure on the abdominal vena cava decreased with PNP but was partly reversed by the addition of PEEP.

CONCLUSION

The application of PEEP on a pre-established PNP during laparoscopic liver resection in normovolemic patients did not decrease CI. Analysis of transmural VC pressure variations confirms that the addition of PEEP may prevent the vena caval collapse induced by PNP.

The PLA2R1-JAK2 pathway upregulates ERRα and its mitochondrial program to exert tumor-suppressive action

Little is known about the biological role of the phospholipase A2 receptor (PLA2R1) transmembrane protein. In recent years, PLA2R1 has been shown to have an important role in regulating tumor-suppressive responses via JAK2 activation, but the underlying mechanisms are largely undeciphered. In this study, we observed that PLA2R1 increases the mitochondrial content, judged by increased levels of numerous mitochondrial proteins, of the mitochondrial structural component cardiolipin, of the mitochondrial DNA content, and of the mitochondrial DNA replication and transcription factor TFAM. This effect of PLA2R1 relies on a transcriptional program controlled by the estrogen-related receptor alpha1 (ERRα) mitochondrial master regulator. Expression of ERRα and of its nucleus-encoded mitochondrial targets is upregulated upon PLA2R1 ectopic expression, and this effect is mediated by JAK2. Conversely, downregulation of PLA2R1 decreases the level of ERRα and of its nucleus-encoded mitochondrial targets. Finally, blocking the ERRα-controlled mitochondrial program largely inhibits the PLA2R1-induced tumor-suppressive response. Together, our data document ERRα and its mitochondrial program as downstream effectors of the PLA2R1-JAK2 pathway leading to oncosuppression.

Monitoring CO2 invasion processes at the pore scale using geological labs on chip

In order to investigate at the pore scale the mechanisms involved during CO2 injection in a water saturated pore network, a series of displacement experiments is reported using high pressure micromodels (geological labs on chip - GLoCs) working under real geological conditions (25 < T (°C) < 75 and 4.5 < p (MPa) < 8). The experiments were focused on the influence of three experimental parameters: (i) the p, T conditions, (ii) the injection flow rates and (iii) the pore network characteristics. By using on-chip optical characterization and imaging approaches, the CO2 saturation curves as a function of either time or the number of pore volume injected were determined. Three main mechanisms were observed during CO2 injection, namely, invasion, percolation and drying, which are discussed in this paper. Interestingly, besides conventional mechanisms, two counterintuitive situations were observed during the invasion and drying processes.

Bulk magnetic terahertz metamaterials based on dielectric microspheres

Rigid metamaterials were prepared by embedding TiO₂ microspheres into polyethylene. These structures exhibit a series of Mie resonances where the lowest-frequency one is associated with a strong dispersion in the effective magnetic permeability. Using time-domain terahertz spectroscopy, we experimentally demonstrated the magnetic nature of the observed resonance. The presented approach shows a way for low-cost massive fabrication of mechanically stable terahertz metamaterials based on dielectric microresonators.

Observation of B→D(*) π^(+)π^(-)ℓ^(-)ν Decays in e^(+)e^(-) Collisions at the Υ(4S) Resonance

We report on measurements of the decays of B¯ mesons into the semileptonic final states B¯→D^(*)π^(+)π^(-)ℓ^(-)ν¯, where D^(*) represents a D or D^(*) meson and ℓ^(-) is an electron or a muon. These measurements are based on 471×10^(6) BB ¯ pairs recorded with the BABAR detector at the SLAC asymmetric B factory PEP-II. We determine the branching fraction ratios R_{π^{+}π^{-}}^{(*)}=B(B[over ¯]→D^{(*)}π^{+}π^{-}ℓ^{-}ν[over ¯])/B(B[over ¯]→D^{(*)}ℓ^{-}ν[over ¯]) using events in which the second B meson is fully reconstructed. We find R_{π^{+}π^{-}}=0.067±0.010±0.008 and R_{π^{+}π^{-}}^{*}=0.019±0.005±0.004, where the first uncertainty is statistical and the second is systematic. Based on these results and assuming isospin invariance, we estimate that B[over ¯]→D^{(*)}ππℓ^{-}ν[over ¯] decays, where π denotes either a π^{±} and π^{0} meson, account for up to half the difference between the measured inclusive semileptonic branching fraction to charm hadrons and the corresponding sum of previously measured exclusive branching fractions.

CD4 deficit and tuberculosis risk persist with delayed antiretroviral therapy: 5-year data from CIPRA HT-001

SETTING

Port-au-Prince, Haiti.

OBJECTIVE

To determine long-term effects of early vs. delayed initiation of antiretroviral therapy (ART) on immune recovery and tuberculosis (TB) risk in human immunodeficiency virus (HIV) infected individuals.

DESIGN

Open-label randomized controlled trial of immediate ART in HIV-infected adults with CD4 counts between 200 and 350 cells/mm(3) vs. deferring ART until the CD4 count was <200 cells/mm(3). The primary comparisons were CD4 counts over time and risk for incident TB, with 5 years of follow-up.

RESULTS

A total of 816 participants were enrolled, with 408 in each treatment arm. The early treatment group started ART within 2 weeks, while the deferred treatment group started ART a median of 1.3 years after enrollment. After 5 years, the mean CD4 count in the early treatment group was significantly higher than in the deferred treatment group (496 cells/mm(3), 95% confidence interval [CI] 477-515 vs. 373 cells/mm(3), 95%CI 357-389; P < 0.0001). TB risk was higher in the deferred treatment group (unadjusted HR 2.41, 95%CI 1.56-3.74; P < 0.0001) and strongly correlated with lower CD4 counts in time-dependent multivariate analysis.

CONCLUSION

Delays in ART initiation for HIV-infected adults with CD4 counts of 200-350 cells/mm(3) can result in long-term immune dysfunction and persistent increased risk for TB.

First Observation of CP Violation in B[over ¯]^{0}→D_{CP}^{(*)}h^{0} Decays by a Combined Time-Dependent Analysis of BABAR and Belle Data

We report a measurement of the time-dependent CP asymmetry of B[over ¯]^{0}→D_{CP}^{(*)}h^{0} decays, where the light neutral hadron h^{0} is a π^{0}, η, or ω meson, and the neutral D meson is reconstructed in the CP eigenstates K^{+}K^{-}, K_{S}^{0}π^{0}, or K_{S}^{0}ω. The measurement is performed combining the final data samples collected at the ϒ(4S) resonance by the BABAR and Belle experiments at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471±3)×10^{6} BB[over ¯] pairs recorded by the BABAR detector and (772±11)×10^{6} BB[over ¯] pairs recorded by the Belle detector. We measure the CP asymmetry parameters -η_{f}S=+0.66±0.10(stat)±0.06(syst) and C=-0.02±0.07(stat)±0.03(syst). These results correspond to the first observation of CP violation in B[over ¯]^{0}→D_{CP}^{(*)}h^{0} decays. The hypothesis of no mixing-induced CP violation is excluded in these decays at the level of 5.4 standard deviations.

Multidrug resistance protein 3 loss promotes tumor formation by inducing senescence escape

Oncogenic-stress-induced senescence (OIS) is a stress response allowing normal cells, when receiving oncogenic signals, to stably arrest their proliferation. OIS thus acts to prevent aberrant cell proliferation and tumor formation. To identify novel tumor suppressive pathways, we have recently completed a loss-of-function genetic screen to identify novel genes promoting escape from OIS and thus, potentially, tumor formation when their functions are lost. Using this approach, we unexpectedly found that loss of function of the multidrug resistance protein 3 (MRP3 or ABCC3) promotes escape from OIS in human epithelial cells. Importantly, ABCC3 expression is reduced in human skin tumors, and ABCC3-knockout mice display increased sensitivity to RAS-induced skin carcinogenesis, concomitantly with decreased OIS. ABCC3 participates in resistance to chemotherapy via its transporter activity. Our data show that this transporter activity is involved in ABCC3-induced senescence, demonstrating that this protein has a complex role in cancer, since its loss of function may promote escape from OIS and tumor formation whereas its gain of function promotes resistance to chemotherapy.