Transcapillary protein leakage and fluid movement: Effect of venous pressure

The effect of elevating venous pressure (ΔP_v) on the transcapillary escape of albumin (Q_T) in control and papverinized gracilis muscles perfused at constant flow was determined by means of direct monitoring of the rate of accumulation of tissue ¹²⁵I-labeled albumin radioactivity. Simultaneously, transcapillary fluid movement (FM) was assessed volumetrically. Under control isovolumetric conditions, Q_T = 2.25 mg/min · 100 g. In addition to causing an FM of 0.03 ml/min · 100 g · mm Hg, increasing P_v enhanced Q_T by 0.06 mg/min · 100 g · mm Hg. Papverinization itself decreased Q_T to 2.0 mg/min · 100 g and affected FM only slightly. However, the superposition of P_v elevation caused a FM of 0.008 ml/min · 100 g · mm Hg and resulted in Q_T increasing by 0.29 mg/min · 100 g · mm Hg. The results of this study indicate that Q_T is sensitive to changes in microvascular hemodynamics, and thus changes in microvascular pressure may affect FM in two ways, first by increasing the transcapillary pressure gradient and second by augmenting Q_T which may superimpose an oncotic adjunct to FM.     

Leucoxenols A and B,two new phenolics from Bornean medicinal plant Syzygium leucoxylon

The medicinal plant, Syzygium leucoxylon or commonly known as Obah found in North Borneo was considered as traditional medicine by local committee. Two new phenolics, leucoxenols A (1) and B (2) were isolated and identified as major secondary metabolites from the leaves of S. leucoxylon. Their chemical structures were elucidated based on spectroscopic data such as NMR and HRESIMS. Furthermore, these compounds were active against selected strains of fungi.     

GABA is localized in dopaminergic synaptic vesicles in the rodent striatum

Recently, electrophysiological evidence was given for inhibitory postsynaptic responses at dopaminergic striatal synapses. These responses were independent of the vesicular GABA transporter, VGAT, but dependent on the vesicular dopamine transporter VMAT2. The identity and the exact source of the released molecule, as well as the presence of the putative inhibitory transmitter in VMAT2 containing synaptic vesicles remain to be shown. To clarify this, in particular to determine whether GABA is responsible for the inhibitory response at dopaminergic synapses, we used the electron microscopic immunogold method to label in vivo perfusion fixed striatal tissue with antibodies recognising GABA, VGAT, VMAT2 and tyrosine hydroxylase. We show that about 13 % of tyrosine hydroxylase positive and 11 % of VMAT2 axonal terminals in the caudo-putamen contain significant labelling for GABA. Immunogold signals for tyrosine hydroxylase and VGAT was totally segregated into different pools of nerve terminals. Quantitative analyses of the distance between gold particles signalling GABA and synaptic vesicles showed that GABA was as closely associated with synaptic vesicles in tyrosine hydroxylase positive as in tyrosine hydroxylase negative nerve terminals. Likewise, in dopaminergic terminals GABA and VMAT2 immunogold particles showed a close spatial localization, strongly suggesting the presence of GABA in VMAT2 positive synaptic vesicles. Our results suggest that GABA is exocytosed together with dopamine from dopaminergic nerve terminals in the caudo-putamen through VGAT negative and VMAT2 positive synaptic vesicles.     

A Randomized Phase II Trial of mFOLFOX6 + Bevacizumab Alone or with AdCEA Vaccine + Avelumab Immunotherapy for Untreated Metastatic Colorectal Cancer

BackgroundFOLFOX plus bevacizumab is a standard of care (SOC) for first-line treatment of microsatellite-stable metastatic colorectal cancer (MSS mCRC). This study randomized patients to SOC or SOC plus avelumab (anti-PD-L1) plus CEA-targeted vaccine.MethodsPatients with untreated MSS mCRC enrolled to a lead-in arm assessing safety of SOC + immuno-oncology agents (IO). Next, patients were randomized to SOC or SOC + IO. The primary endpoint was progression-free survival (PFS). Multiple immune parameters were analyzed.ResultsSix patients enrolled to safety lead-in, 10 randomized to SOC, and 10 to SOC + IO. There was no difference in median PFS comparing SOC versus SOC + IO (8.8 months (95% CI: 3.3-17.0 months) versus 10.1 months (95% CI: 3.6-16.1 months), respectively; hazard ratio 1.061 [P = .91; 95% CI: 0.380-2.966]). The objective response rate was 50% in both arms. Of patients analyzed, most (8/11) who received SOC + IO developed multifunctional CD4+/CD8+ T-cell responses to cascade antigens MUC1 and/or brachyury, compared to 1/8 who received SOC alone (P = .020). We detected post-treatment changes in immune parameters that were distinct to the SOC and SOC + IO treatment arms. Accrual closed after an unplanned analysis predicted a low likelihood of meeting the primary endpoint.ConclusionsSOC + IO generated multifunctional MUC1- and brachyury-specific CD4+/CD8+ T cells despite concurrent chemotherapy. Although a tumor-directed immune response is necessary for T-cell–mediated antitumor activity, it was not sufficient to improve PFS. Adding agents that increase the number and function of effector cells may be required for clinical benefit.     

Role of cardiopulmonary mechanoreceptors in the postural regulation of renin

To change the stretch on cardiopulmonary mechanoreceptors, large shifts of blood in the capacity space were elicited by tilting and by exerting positive lower body pressure in the tilted position. Twelve volunteers underwent invasive hemodynamic studies and in 10 other subjects cardiac size was determined by radionuclide cardiography. In all 22 subjects tilting caused the expected increase of renin, which was abolished by lower body compression. Decompression caused renin to increase again. Right atrial pressure in invasive studies and end-systolic and end-diastolic counts in noninvasive studies showed a significant and strong negative correlation with renin and norepinephrine levels. Thus, the degree of stretch of the cardiopulmonary mechanoreceptors is a major determinant of reflex regulation of renin release in humans.     

Oral Anticoagulant Type and Outcomes After Transcatheter Aortic Valve Replacement

ObjectivesThe purpose of the study was to investigate the impact of oral anticoagulation (OAC) type on clinical outcomes 1 year after transcatheter aortic valve replacement (TAVR).BackgroundNon–vitamin K oral anticoagulants (NOACs) are superior to vitamin K antagonists (VKAs) in nonvalvular atrial fibrillation (AF), while their comparative performance among patients in need of OAC undergoing TAVR is underinvestigated.MethodsThe study enrolled 962 consecutive patients who underwent TAVR in 4 tertiary European centers and were discharged on either NOACs (n = 326) or VKAs (n = 636). By using propensity scores for inverse probability of treatment weighting (IPTW), the comparison of treatment groups was adjusted to correct for potential confounding.ResultsMean age and Society of Thoracic Surgeons score of the population were 81.3 ± 6.3 years and 4.5% (interquartile range: 3.0% to 7.3%); 52.5% were women and a balloon-expandable valve was used in 62.7% of cases. The primary outcome of interest, combined incidence of all-cause mortality, myocardial infarction, and any cerebrovascular event at 1-year after TAVR, was 21.2% with NOACs versus 15.0% with VKAs (hazard ratio [HR]: 1.44; 95% confidence interval [CI]: 1.00 to 2.07; p = 0.050, IPTW-adjusted). The 1-year incidence of any Bleeding Academic Research Consortium bleeds and all-cause mortality were comparable between the NOAC and VKA groups, 33.9% versus 34.1% (HR: 0.97; 95% CI: 0.74 to 1.26; p = 0.838, IPTW-adjusted) and 16.5% versus 12.2% (HR: 1.36; 95% CI: 0.90 to 2.06; p = 0.136, IPTW-adjusted), respectively.ConclusionsChronic use of both NOACs and VKAs among patients in need of OAC after TAVR are comparable regarding 1-year bleeding risk. The higher ischemic event rate observed with NOACs needs to be evaluated in large randomized trials.