Effect of nonionic surfactants on Rhizopus homothallicus lipase activity: a comparative kinetic study

Based on amino-terminal sequencing and mass spectrometry data on the Rhizopus homothallicus lipase extracted using solid (SSF) and submerged state fermentation (SmF) methods, we previously established that the two enzymes were identical. Differences were observed, however, in terms of the specific activity of these lipases and their inhibition by diethyl p-nitrophenyl phosphate (E600). The specific activity of the SSF lipase (10,700 μmol/min/mg) was found to be 1.2-fold that of SmF lipase (8600 μmol/min/mg). These differences might be the result of residual Triton X-100 molecules interacting with the SSF lipase. To check this hypothesis, the SmF lipase was incubated with submicellar concentrations of Triton X-100. The specific activity of the lipase increased after this treatment, reaching similar values to those measured with the SSF lipase. Preincubating SSF and SmF lipases with E600 at a molar excess of 100 for 1 h resulted in 80% and 60% enzyme inhibition levels, respectively. When the SmF lipase was preincubated with Triton X-100 for 1 h at a concentration 100 times lower than the Trition X-100 critical micellar concentration, the inhibition of the lipase by E600 increased from 60% to 80%. These results suggest that residual detergent monomers interacting with the enzyme may after the kinetic properties of the Rh. homothallicus lipase.     

Shear-thickening and shear-induced pattern formation in starch solutions

Since Dintzis et al. reported shear-thickening behavior and shear-induced pattern formation in semidilute starch solutions for the first time in 1995, considerable efforts have been made to understand the science behind these observations. Despite these efforts, however, many questions regarding this behavior of starch solutions remain. Using a Brookfield programmable rheometer and a custom-built shear microscope, starch solutions in alkaline solution medium were investigated. In this report, we present data leading to the following conclusions: (1) gently prepared starch solutions are macroscopically heterogeneous with regions of highly concentrated gel-like structures dispersed in dilute starch solution; (2) shear breaks up these heterogeneous regions, increasing in viscosity (shear-thickening) which is thus seen to be a result of an increase in the concentration of dissolved starch; (3) pattern formation, observed when the solution is exposed to higher shear rate, is the result of a separate shear-induced aggregation process; and (4) aggregations are not induced below a certain critical threshold shear rate and time is also a factor in the behavior of the aggregate.     

Potent and highly selective DP1 antagonists with 2,3,4,9-tetrahydro-1H-carbazole as pharmacophore

We discovered that the introduction of a methyl group to the benzylic position of the N-benzyl group in lead compound 1a has a dramatic effect on improving the binding selectivity of this ligand for the prostanoid receptors DP1 (receptor for prostaglandin D(2)) as compared to TP (receptor for thromboxane A(2)). Based on this discovery, we have synthesized a series of potent and highly selective DP1 antagonists. Among them, compound 1h was identified as a highly selective DP1 antagonist with excellent overall properties. It has a K(i) of 0.43 nM to DP1 in binding assay and an IC(50) of 2.5 nM in the DP1 functional assay. Its selectivity for DP1 over TP (the most potent receptor after DP1) exceeds 750-fold based on both binding and functional assays. These properties make 1h a very potent and highly selective DP1 receptor antagonist suitable for investigating the biological functions of DP1 in normal physiology and models of disease.     

Characterization of typo-, regio-, and stereo-selectivities of babaco latex lipase in aqueous and organic media

The unripe fruit of babaco (Vasconcellea × heilbornii; syn. Carica pentagona) contains a latex, similar to that in Carica papaya, which exhibits lipolytic activity. Herein, the regioselectivity, stereoselectivity and typoselectivity in both hydrolysis and acyltransfer reactions of babaco latex lipases were studied and compared to those of Carica papaya latex. In hydrolysis, both biocatalysts are 1,3-regioselective with ratios for 1,2-2,3-diacylglycerols/1,3-diacylglycerol of 6.5 and 21 for babaco and papaya, respectively. In contrast, papaya latex had a slight sn-3 stereopreference. Babaco latex displayed a higher activity on triacylglycerols with short chain and unsaturated fatty acids     

Clinical Usefulness of Procalcitonin and C-Reactive Protein as Outcome Predictors in Critically Ill Patients with Severe Sepsis and Septic Shock

Sepsis is a major cause of mortality and morbidity in critically ill patients. Procalcitonin (PCT) and C-reactive protein (CRP) are the most frequently used biomarkers in sepsis. We investigated changes in PCT and CRP concentrations in critically ill patients with sepsis to determine which biochemical marker better predicts outcome. We retrospectively analyzed 171 episodes in 157 patients with severe sepsis and septic shock who were admitted to the Samsung Medical Center intensive care unit from March 2013 to February 2014. The primary endpoint was patient outcome within 7 days from ICU admission (treatment failure). The secondary endpoint was 28-day mortality. Severe sepsis was observed in 42 (25%) episodes from 41 patients, and septic shock was observed in 129 (75%) episodes from 120 patients. Fifty-five (32%) episodes from 42 patients had clinically-documented infection, and 116 (68%) episodes from 99 patients had microbiologically-documented infection. Initial peak PCT and CRP levels were not associated with treatment failure and 28-day mortality. However, PCT clearance (PCTc) and CRP (CRPc) clearance were significantly associated with treatment failure (p = 0.027 and p = 0.030, respectively) and marginally significant with 28-day mortality (p = 0.064 and p = 0.062, respectively). The AUC for prediction of treatment success was 0.71 (95% CI, 0.61–0.82) for PCTc and 0.71 (95% CI, 0.61–0.81) for CRPc. The AUC for survival prediction was 0.77 (95% CI, 0.66–0.88) for PCTc and 0.77 (95% CI, 0.67–0.88) for CRPc. Changes in PCT and CRP concentrations were associated with outcomes of critically ill septic patients. CRP may not be inferior to PCT in predicting outcome in these patients.     

Comparison of Clinical Efficacy and Safety between Indacaterol and Tiotropium in COPD: Meta-Analysis of Randomized Controlled Trials

Two once-daily inhaled bronchodilators, indacaterol and tiotropium, are widely used as first-line therapy in stable COPD patients. This study was performed to compare the clinical efficacy and safety between indacaterol and tiotropium in patients with moderate-to-severe COPD. MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were searched to identify all published randomized controlled trials (RCTs). The primary outcome was trough forced expiratory volume in 1 second (FEV₁) at week 12. Four RCTs were eligible for inclusion (three RCTs with moderate-to-severe COPD patients and one RCT with only severe COPD patients). Trough FEV₁ at weeks 12 and 26 were not significantly different between indacaterol and tiotropium by the standardized mean difference with 0.014 (95% CI, -0.036, 0.063, I²= 23.5%) and with 0.037 (95% CI, -0.059 to 0.133, I²= 0%) along with differences in means of 0.003L and 0.014L, respectively. Indacaterol and tiotropium also showed similar St. George`s Respiratory Questionnaire (SGRQ) total scores and percentages of patients with SGRQ improvement (≥ 4 units) at week 26. The incidences of nasopharyngitis, serious cardiovascular events, and serious adverse events were not different between indacaterol and tiotropium, while those of cough (OR = 1.68, P < 0.001, and RR = 1.63) and COPD worsening (OR = 1.18, P = 0.003, and RR = 1.12) were higher for indacaterol than tiotropium. However, when one study with only severe COPD patients was removed from the meta-analysis, the difference in the incidence of COPD worsening between indacaterol and tiotropium became non-significant (OR = 1.13, P = 0.204, and RR = 1.09). The clinical efficacy and serious adverse events between indacaterol and tiotropium were equivocal in patients with moderate-to-severe COPD. Cough is a common complaint associated with indacaterol, and COPD worsening needs to be carefully monitored in severe COPD patients when treated with indacaterol.     

PV1 down‐regulation via shRNA inhibits the growth of pancreatic adenocarcinoma xenografts

PV1 is an endothelial‐specific protein with structural roles in the formation of diaphragms in endothelial cells of normal vessels. PV1 is also highly expressed on endothelial cells of many solid tumours. On the basis of in vitro data, PV1 is thought to actively participate in angiogenesis. To test whether or not PV1 has a function in tumour angiogenesis and in tumour growth in vivo, we have treated pancreatic tumour‐bearing mice by single‐dose intratumoural delivery of lentiviruses encoding for two different shRNAs targeting murine PV1. We find that PV1 down‐regulation by shRNAs inhibits the growth of established tumours derived from two different human pancreatic adenocarcinoma cell lines (AsPC‐1 and BxPC‐3). The effect observed is because of down‐regulation of PV1 in the tumour endothelial cells of host origin, PV1 being specifically expressed in tumour vascular endothelial cells and not in cancer or other stromal cells. There are no differences in vascular density of tumours treated or not with PV1 shRNA, and gain and loss of function of PV1 in endothelial cells does not modify either their proliferation or migration, suggesting that tumour angiogenesis is not impaired. Together, our data argue that down‐regulation of PV1 in tumour endothelial cells results in the inhibition of tumour growth via a mechanism different from inhibiting angiogenesis.     

Gamma interferon can prevent herpes simplex virus type 1 reactivation from latency in sensory neurons

We recently demonstrated that CD8(+) T cells could block herpes simplex virus type 1 (HSV-1) reactivation from latency in ex vivo trigeminal ganglion (TG) cultures without destroying the infected neurons. Here we establish that CD8(+) T-cell prevention of HSV-1 reactivation from latency is mediated at least in part by gamma interferon (IFN-gamma). We demonstrate that IFN-gamma was produced in ex vivo cultures of dissociated latently infected TG by CD8(+) T cells that were present in the TG at the time of excision. Depletion of CD8(+) T cells or neutralization of IFN-gamma significantly enhanced the rate of HSV-1 reactivation from latency in TG cultures. When TG cultures were treated with acyclovir for 4 days to insure uniform latency, supplementation with recombinant IFN-gamma blocked HSV-1 reactivation in 80% of cultures when endogenous CD8(+) T cells were present and significantly reduced and delayed HSV-1 reactivation when CD8(+) T cells or CD45(+) cells were depleted from the TG cultures. The effectiveness of recombinant IFN-gamma in blocking HSV-1 reactivation was lost when its addition to TG cultures was delayed by more than 24 h after acyclovir removal. We propose that when the intrinsic ability of neurons to inhibit HSV-1 gene expression is compromised, HSV-specific CD8(+) T cells are rapidly mobilized to produce IFN-gamma and perhaps other antiviral cytokines that block the viral replication cycle and maintain the viral genome in a latent state.