Observation of the Exotic 0_{2}^{+} Cluster State in ^{8}He

We report here the first observation of the 0_{2}^{+} state of ^{8}He, which has been predicted to feature the condensatelike α+^{2}n+^{2}n cluster structure. We show that this state is characterized by a spin parity of 0^{+}, a large isoscalar monopole transition strength, and the emission of a strongly correlated neutron pair, in line with theoretical predictions. Our finding is further supported by the state-of-the-art microscopic α+4n model calculations. The present results may lead to new insights into clustering in neutron-rich nuclear systems and the pair correlation and condensation in quantum many-body systems under strong interactions.

Estrogen receptor β attenuates renal fibrosis by suppressing the transcriptional activity of Smad3

Renal fibrosis (RF) is a common pathway leading to chronic kidney disease (CKD), which lacks effective treatment. While estrogen receptor beta (ERβ) is known to be present in the kidney, its role in RF remains unclear. The present study aimed to investigate the role and underlying mechanism of ERβ during RF progression in patients and animal models with CKD. We found that ERβ was highly expressed in the proximal tubular epithelial cells (PTECs) in healthy kidneys but its expression was largely lost in patients with immunoglobin A nephropathy (IgAN) and in mice with unilateral ureter obstruction (UUO) and subtotal nephrectomy (5/6Nx). ERβ deficiency markedly exacerbated, whereas ERβ activation by WAY200070 and DPN attenuated RF in both UUO and 5/6Nx mouse models, suggesting a protective role of ERβ in RF. In addition, ERβ activation inhibited TGF-β1/Smad3 signaling, while loss of renal ERβ was associated with overactivation of the TGF-β1/Smad3 pathway. Furthermore, deletion or pharmacological inhibition of Smad3 prevented the loss of ERβ and RF. Mechanistically, activation of ERβ competitively inhibited the association of Smad3 with the Smad-binding element, thereby downregulating the transcription of the fibrosis-related genes without altering Smad3 phosphorylation in vivo and in vitro. In conclusion, ERβ exerts a renoprotective role in CKD by blocking the Smad3 signaling pathway. Thus, ERβ may represent as a promising therapeutic agent for RF.

[Peripheral blood KCNMA1 methylation level is associated with the occurrence and progression of lung cancer]

OBJECTIVE

To explore the association of KCNMA1 gene methylation levels in peripheral blood with lung cancer.

METHODS

The methylation levels of 4 CpG sites in KCNMA1 gene were quantitatively detected in 285 patients with lung cancer, 186 age- and sex-matched patients with benign pulmonary nodules and 278 matched healthy control subjects using mass spectrometry (MALDI-TOF-MS). The association of KCNMA1 methylation levels with lung cancer was analyzed using logistic regression models adjusted for covariates. The KCNMA1 methylation levels in different subgroups of lung cancer patients were compared using Mann-Whitney U test.

RESULTS

In subjects over 55 years and in female subjects, the highest quartile (Q4) vs the lowest quartile (Q1) of KCNMA1_CpG_5 methylation levels were significantly correlated with lung cancer (for subjects over 55 years: OR=2.60, 95% CI: 1.25-5.41, P=0.011; for female subjects: OR=2.09, 95% CI: 1.03?4.26, P=0.042). From Q2 to Q4 of KCNMA1_CpG_5 methylation levels, their correlation with lung cancer became gradually stronger (P=0.003 and 0.038, respectively). In male subjects, the OR of Q4 of KCNMA1_CpG_5 methylation levels was 0.35 in patients with lung cancer as compared with patients with benign nodules (95% CI: 0.16-0.79, P=0.012). KCNMA1_CpG_3 methylation level was significantly lower in invasive adenocarcinoma than in noninvasive adenocarcinoma (P=0.028), and that of KCNMA1_CpG_1 was significantly higher in patients with larger tumors (T2-4) than in those with smaller tumors (T1) (P=0.021).

CONCLUSION

The change of peripheral blood KCNMA1 methylation level is correlated with the occurrence and development of lung cancer.

Neutral amino acid transporter SLC38A2 protects renal medulla from hyperosmolarity-induced ferroptosis

Hyperosmolarity of the renal medulla is essential for urine concentration and water homeostasis. However, how renal medullary collecting duct (MCD) cells survive and function under harsh hyperosmotic stress remains unclear. Using RNA-Seq, we identified SLC38A2 as a novel osmoresponsive neutral amino acid transporter in MCD cells. Hyperosmotic stress-induced cell death in MCD cells occurred mainly via ferroptosis, and it was significantly attenuated by SLC38A2 overexpression but worsened by Slc38a2-gene deletion or silencing. Mechanistic studies revealed that the osmoprotective effect of SLC38A2 is dependent on the activation of mTORC1. Moreover, an in vivo study demonstrated that Slc38a2-knockout mice exhibited significantly increased medullary ferroptosis following water restriction. Collectively, these findings reveal that Slc38a2 is an important osmoresponsive gene in the renal medulla and provide novel insights into the critical role of SLC38A2 in protecting MCD cells from hyperosmolarity-induced ferroptosis via the mTORC1 signalling pathway.

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

The Combined Effect of Hearing Impairment and Cognitive Impairment with Health-Related Outcomes in Chinese Older People

OBJECTIVES

To determine the risk of poor health-related outcomes in older adults with cooccurring hearing impairment and cognitive impairment, and to compare the risk of hearing impairment only, cognitive impairment only, and multiple morbidities.

DESIGN

Cross-sectional study.

SETTING

Community-dwelling older adults aged 60 years and older were included.

PARTICIPANTS

The data of missing hearing and cognitive status were excluded, and 3770 older people participated in the study.

MEASUREMENTS

The hearing function evaluation was conducted by questionnaire survey. Assessment of cognitive function was completed using the SPMSQ scale. The subjects were divided into hearing impairment and cognitive impairment group, hearing impairment only group, cognitive impairment only group and neither group. Multiple logistic regression was used to analyze the risks of hearing and cognitive impairment and health-related condition.

RESULTS

The prevalence of hearing impairment and cognitive impairment, hearing impairment only, cognitive impairment only, and neither were 9.4%, 8.3%, 29.9% and 52.4%, respectively. Compared with the control group, the individuals with hearing impairment and cognitive impairment were associated with depression (OR=3.48, 95% CI=2.66, 4.56), anxiety (OR=2.35, 95% CI=1.92, 3.33), frailty (OR=4.30, 95% CI=2.89, 6.40), and ADL impairment (OR=2.77, 95% CI=2.03, 3.77).

CONCLUSION

The studies shows that hearing impairment combined with cognitive impairment is significantly associated with anxiety, depression, frailty, and ADL impairment. Comprehensive management and intervention should be provided for older people to reduce the occurrence of adverse health consequences.

Genome-wide association studies for growth-related traits in a crossbreed pig population

Growth-related traits are important economic traits in the pig industry that directly influence pork production efficiency. To detect quantitative trait loci and candidate genes affecting growth traits, genome-wide association studies were performed for backfat thickness (BF) and loin muscle depth (LMD) in 370 Chuying-black pigs using Illumina PorcineSNP50 BeadChip array. We totally identified 14 BF-associated SNPs, which included 11 genome-wide SNPs (P < 1.39E-06) and 3 chromosome-wide suggestive SNPs (P < 2.79E-05) and for LMD, 9 SNPs surpassed the genome-wide significant threshold (P < 1.39E-06). These SNPs explained 30.33 and 27.51% phenotypic variance for BF and LMD respectively. Furthermore, 14 and 9 genes nearest to the significant SNPs were selected to be candidate genes, including MAGED1, GPHN, CCSER1, and GUCY2D for BF and PARM1, COL18A1, HSF5, and SCML2 genes for LMD. One significant SNP, which explained 6.07% of phenotypic variance for BF, mapped to a pleiotropic quantitative trait locus with a 494-kb interval. Together, the SNPs and candidate genes identified in this study will advance our understanding of the complex genetic architecture of BF and LMD traits, and they will also provide important clues for future implementation of a genomic selection program in Chuying-black pigs.

Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 ¹/₂ years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

Population structure and genetic diversity of four Henan pig populations

To investigate the population structure and genetic diversity of Henan indigenous pig breeds, samples from a total of 78 pigs of 11 breeds were collected, including four pig populations from Henan Province, three Western commercial breeds, three Chinese native pig breeds from other provinces and one Asian wild boar. The genotyping datasets were obtained by genotyping-by-sequencing technology. We found a high degree of polymorphism and rapid linkage disequilibrium decay in Henan pigs. A neighbor-joining tree, principal component analysis and structure analysis revealed that the Huainan and Erhualian pigs were clustered together and that the Queshan black pigs were clearly grouped together but that the Nanyang and Yuxi pigs were extensively admixed with Western pigs. In addition, heterozygosity values might indicate that Henan indigenous pigs, especially the Queshan black and Huainan pigs, were subjected to little selection during domestication. The results presented here indicate that Henan pig breeds were admixed from Western breeds, especially Nanyang and Yuxi pigs. Therefore, establishment of purification and rejuvenation systems to implement conservation strategies is urgent. In addition, it is also necessary to accelerate genetic resources improvement and utilization using modern breeding technologies, such as genomic selection and genome-wide association studies.

Genome-wide association study identifies variants in the CAPN9 gene associated with umbilical hernia in pigs

Pig umbilical hernia (UH) affects pig welfare and brings considerable economic loss to the pig industry. To date, the molecular mechanisms underlying pig UH are still poorly understood. To identify potential loci for susceptibility to this disease, we performed a genome-wide association study in an Erhualian × Shaziling F₂ intercross population. A total of 45 animals were genotyped using Illumina Porcine SNP60 BeadChips. We observed a SNP (rs80993347) located in the calpain-9 (CAPN9) gene on Sus scrofa chromosome 14 that was significantly associated with UH (P = 1.97 × 10^-10 ). Then, we identified a synonymous mutation rs321865883 (g.20164T>C) in exon 10 of the CAPN9 gene that distinguished two affected individuals (CC) from their normal full-sibs (TC). Finally, quantitative polymerase chain reaction was explored to investigate the mRNA expression profile of the CAPN9 gene in 12 tissues in Yorkshire pigs at different developmental stages (3, 90 and 180 days). CAPN9 showed high expression levels in the gastrointestinal tract at these three growth stages. The results of this study indicate that the CAPN9 gene might be implicated in UH. Further studies are required to establish a role of CAPN9 in pig UH.

Increased circulating microparticles in women with preeclampsia

INTRODUCTION

Preeclampsia (PE) is associated with hypercoagulability, endothelial dysfunction and inflammation, which generate microparticles (MPs). Therefore, MPs may be important for PE.

METHODS

We established a verified MP measurement procedure to detect MPs in nonpregnant women (n = 25), healthy pregnant women (n = 29) and PE women (n = 73) and compared their MP levels.

RESULTS

Microparticles prepared from platelets (PMPs), endothelial cells (EMPs) and leucocytes (LMPs) were confirmed by transmission electron microscopy and were analysed by our established flow cytofluorimetric approach, which showed good specificity for determining the cell origin and level of MPs. The levels of total MPs (tMPs) and PMPs in the healthy pregnant group were significantly higher than those in the nonpregnant group (158.78 vs 93.00 and 45.04 vs 17.41, P = .004 and P = .007, respectively) but were not significantly different from those of the PE group. However, EMPs and LMPs were significantly higher in the PE group than in the healthy pregnant group (14.62 vs 11.48 and 8.94 vs 5.03, P = .015 and P < .001, respectively). Furthermore, the area under the receiver operating characteristic curves (AUC) for EMPs, LMPs and the combined sum of EMPs and LMPs were 0.661, 0.746 and 0.718, respectively (P < . 05); at their optimal cut-off values, the sensitivities were 50.68%, 87.67% and 46.58%, respectively, and the specificities were 80.77%, 58.33% and 95.65%, respectively.

CONCLUSION

Determining the MP level, especially that of EMPs and LMPs, by a specificity-verified method may reflect the endothelial dysfunction and inflammation involved in PE pathogenesis.

Indazolo[3,2-b]quinazolinones Attack Hepatocellular Carcinoma Hep3B Cells by Inducing Mitochondrial-Dependent Apoptosis and Inhibition of Nrf2/ARE Signaling Pathway

BACKGROUND AND OBJECTIVE

Hepatocellular carcinoma (HCC) is the second leading cause of cancer death worldwide. Genotoxic stress resistance in patients often contributes to poor clinical outcomes, and is intensively associated to the upregulation of Nrf2/ARE signaling pathway. In this study, we examined the connection between the anticancer activity of two novel indazolo[3,2-b]quinazolinone (IQ) derivatives, IQ-7 and IQ-12, and their effect on the Nrf2/ARE signaling pathway.

METHODS

We initially measured the cytotoxicity of IQ-7 and IQ-12 in Hep3B (human hepatoma cell) and HL-7702 (normal human liver cell) cell lines, then further detected their effects on Nrf2/ARE signaling pathway and apoptosis.

RESULTS

IQ-7 and IQ-12 downregulated the expression levels of Nrf2 and its downstream target genes, such as NQO1, HO-1 and Gclc. In Hep3B cells treated with IQ-7 or IQ-12, the mitochondrial membrane potential decreased dramatically while the expression level of the pro-apoptotic protein VDAC1 and anti-apoptotic protein Bcl-2 significantly increased and decreased, respectively. In addition, IQ-7 (but not IQ-12) also induced the activity of Caspase-3. Interestingly, IQ-7 appeared to selectively inhibit Hep3B cells while having rare adverse effect on HL-7702 cells.

CONCLUSION

The two compounds were shown to induce apoptosis and inhibit the Nrf2/ARE signaling pathway in Hep3B cells, and IQ-7 was suggested a degree of specificity against cancer cells. The design of these compounds may therefore represent a new strategy for designing quinazoline derivatives that could selectively target carcinoma cells.

Observation of enhanced monopole strength and clustering in (12)Be

In a recent breakup-reaction experiment using a Be12 beam at 29  MeV/nucleon, the 0+ band head of the expected He4+He8 molecular rotation was clearly identified at about 10.3 MeV, from which a large monopole matrix element of 7.0±1.0  fm2 and a large cluster-decay width were determined for the first time. These findings support the picture of strong clustering in Be12, which has been a subject of intense investigations over the past decade. The results were obtained thanks to a specially arranged detection system around zero degrees, which is essential in determining the newly emphasized monopole strengths to signal the cluster formation in a nucleus.

Modulation of ascorbic acid-induced DNA cleavage by polyamide: cleavage manner, kinetics and mechanism

Manipulation of DNA presents a great interest in biotechnology and therapeutics. The molecules that damage DNA selectively offer new prospects for controlled manipulation of DNA. The conjugations of DNA-code reading molecules such as polyamides to reagents that induce DNA damages provide an approach to reach this goal. In this work, a new compound which contained polyamide and ascorbic acid conjugated by flexible linker (polyamide-Vc), was successfully synthesized, characterized, and evaluated as DNA cleavage agent, compared with that by using ascorbic acid molecule. The kinetics data showed that polyamide-Vc successfully promoted the cleavage of plasmid DNA, with k(max) of 0.314 h(-1) and K(d) of 0.105 mM. The evaluation of DNA linearization elicited that the activity of cleaving double-strand in the supercoiled pUC18 plasmid DNA by polyamide-Vc was enhanced remarkably, achieving n1/n2 ratio of 13.9 at 1.2 mM for 1 h. The introduction of polyamide to Vc could also partially weaken the inhibition of hydrogen radical to double-strand cleavage process because of its good binding activity to DNA. We anticipate that this work could provide a method for improving the efficiency of double-strand cleavage, especially to oxidative cleavage agents.

Control of electroosmotic flow by polymer coating: effects of the electrical double layer

We report on the molecular dynamics simulations of electroosmotic flow control by polymer coating. We show that polymer coating modulates the flow by rendering drag to fluids and by changing the ion distribution and ion-surface interactions in the electrical double layer. Because of the latter two effects, the polymer coating can even enhance the flow under certain conditions. Identifying the effects of these processes is crucial for the rational design of polymer coating for electroosmotic flow control.

Differential ion transport induced electroosmosis and internal recirculation in heterogeneous osmosis membranes

Water and ion transport through a heterogeneous membrane separating two electrolyte solutions at different concentrations is investigated by using molecular dynamics simulations. The membrane features pairs of oppositely charged pores with identical diameters. Simulation results indicate that the differential transport of K(+) and Cl(-) ions through the membrane pores creates an electrical potential difference across the membrane, which then induces an electroosmotic water flux. The induced electroosmosis creates an internal recirculation loop of water between adjacent pores. The implications of these new observations are discussed.

Scaling of electrokinetic transport in nanometer channels

Electrokinetic transport is a popular transport mechanism used in nanofluidic systems, and understanding its scaling behavior is important for the design and optimization of nanofluidic devices. In this article, we report on the scaling of electroosmotic flow and ionic conductivity in positively charged slit nanochannels by using continuum and atomistic simulations. The effects of confinement and surface charge are discussed in detail. In particular, we found that the viscosity of the interfacial water increases substantially as the surface charge density increases and the electrophoretic mobility of the interfacial ions decreases. We show that such effects can influence the scaling of the electrokinetic transport in confined nanochannels significantly.

Charge inversion and flow reversal in a nanochannel electro-osmotic flow

Ion distribution and velocity profiles for electro-osmotic flow in a 3.49 nm wide slit channel with a surface charge density of -0.285 C/m(2) are studied using molecular dynamics simulations. Simulation results indicate that the concentration of the co-ion exceeds that of the counterion in the region 0.53 nm away from the channel wall, and the electro-osmotic flow is in the opposite direction to that predicted by the classical continuum theory. The charge inversion is mainly caused by the molecular nature of water and ions. The flow reversal is caused by the immobilization of counterions adsorbed on the channel wall and due to the charge inversion phenomena.

A mouse model of arterial gene transfer: antigen-specific immunity is a minor determinant of the early loss of adenovirus-mediated transgene expression

We developed a murine model of arterial gene transfer and used it to test the role of antigen-specific immunity in the loss of adenovirus-mediated transgene expression. Adenoviral vectors encoding either beta-galactosidase (beta-gal) or green fluorescent protein were infused to the lumen of normal common carotids of CD-1 and C57BL/6 mice and atherosclerotic carotids of Apoe(-/-) mice. At 3 days after gene transfer, significant reporter gene expression was detected in all strains. Transgene expression was transient, with expression undetectable at 14 days. Next, a beta-gal-expressing vector was infused into carotids of ROSA26 mice (transgenic for, and therefore tolerant of, beta-gal) and RAG-2(-/-) mice (deficient in recombinase-activating gene [RAG]-2 and therefore lacking in antigen-specific immunity). beta-Gal expression was again high at 3 days but declined substantially (>90%) by 14 days. In vivo labeling with bromodeoxyuridine revealed that carotid endothelial proliferation was increased dramatically by the gene-transfer procedure alone, likely leading to the loss of episomal adenoviral DNA. Gene transfer to normal and atherosclerotic mouse carotids can be accomplished; however, elimination of antigen-specific immune responses does not prevent the early loss of adenovirus-mediated transgene expression. Efforts to prolong adenovirus-mediated transgene expression in the artery wall must be redirected. These efforts will likely include strategies to avoid the consequences of increased cell turnover. Nevertheless, despite the brevity of expression, this mouse model of gene transfer to normal and severely atherosclerotic arteries will likely be useful for investigating the genetic basis of vascular disease and for developing gene therapies.

Protein kinase C beta regulates heterologous desensitization of thrombin receptor (PAR-1) in endothelial cells

We studied the effects of protein kinase C (PKC) activation on endothelial cell surface expression and function of the proteolytically activated thrombin receptor 1 (PAR-1). Cell surface PAR-1 expression was assessed by immunofluorescence (using anti-PAR-1 monoclonal antibody), and receptor activation was assessed by measuring increases in cytosolic Ca2+ concentration in human dermal microvascular endothelial cells (HMEC) exposed to alpha-thrombin or phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA). Immunofluorescence showed that thrombin and TPA reduced the cell surface expression of PAR-1. Prior exposure of HMEC to thrombin for 5 min desensitized the cells to thrombin, indicating homologous PAR-1 desensitization. In contrast, prior activation of PKC with TPA produced desensitization to thrombin and histamine, indicating heterologous PAR-1 desensitization. Treatment of cells with staurosporine, a PKC inhibitor, fully prevented heterologous desensitization, whereas thrombin-induced homologous desensitization persisted. Depletion of PKC beta isozymes (PKC beta I and PKC beta II) by transducing cells with antisense cDNA of PKC beta I prevented the TPA-induced decrease in cell surface PAR-1 expression and restored approximately 60% of the cytosolic Ca2+ signal in response to thrombin. In contrast, depletion of PKC beta isozymes did not affect the loss of cell surface PAR-1 and induction of homologous PAR-1 desensitization by thrombin. Therefore, homologous PAR-1 desensitization by thrombin occurs independently of PKC beta isozymes, whereas the PKC beta-activated pathway is important in signaling heterologous PAR-1 desensitization in endothelial cells.

Mechanisms of liquid flux across pulmonary alveolar epithelial cell monolayers

Active transport of sodium by pulmonary alveolar epithelial cells (AEC) is believed to be an important component of edema clearance in the normal and injured lung. Data supporting this premise have come from measurements of sodium movement across AEC monolayers or from perfused lung model systems. However, direct measurement of fluid flux across AEC monolayers has not been reported. In the present work, AEC were studied with an experimental system for the measurement of fluid flux (Jv) across functionally intact cell monolayers. Primary adult rat type II alveolar epithelial cells were cultured on 0.8 micron nuleopore filters previously coated with gelatin and fibronectin. Intact monolayers were verified by high electrical resistance (> 1000 omega) at 4-5 d of primary culture. At the same time interval, transmission electron microscopy revealed cells with type I cell-like morphology throughout the monolayer. These were characterized by both adherens and tight junctional attachments. Fluid flux across the monolayers was measured volumetrically over a period of 2 h in the presence of HEPES-buffered DMEM containing 3% fatty acid-free bovine serum albumin. Flux (Jv) was inhibited 39% by 1 X 10(-4) M ouabain (P < 0.01) and 27% by 5 X 10(-4) M amiloride (P < 0.05). These data support the concept that AEC Na+/K(+)-ATPase and Na+ transport systems are important determinants of AEC transepithelial fluid movement in vitro.

Tumor necrosis factor decreases thrombin receptor expression in endothelial cells

We examined the effects of the proinflammatory cytokine, tumor necrosis factor-alpha (TNF alpha) on the expression of proteolytically activated thrombin receptor (PATR) in human umbilical vein endothelial cells (HUVEC). PATR mRNA and protein levels were measured in confluent HUVEC monolayers after challenge with TNF alpha. Northern analysis indicated that TNF alpha treatment resulted in 2- to 3-fold decrease in PATR mRNA in a time- and dose-dependent manner. PATR mRNA level returned to the control level within 6 hr. The nuclear run-on assay indicated that the decreased mRNA signal was due to reduction in the transcription rate. Immunoblotting experiments indicated that the decrease in expression of PATR protein followed in time the decrease in mRNA; the lowest level of protein expression was achieved at 22 hr after TNF alpha treatment. PATR protein returned to basal value within 40 hr after TNA alpha challenge. To assess alterations in endothelial cell function after TNF alpha treatment, we measured thrombin-induced increase in cytosolic Ca2+ ([Ca2+]i) and the cell shape change (measured by decrease in electrical impedance of endothelial cell monolayer). In HUVEC treated with TNF alpha (100 U/ml for 22 hr), the rise in [Ca2+]i after thrombin challenge was approximately 2-fold less than in control thrombin-treated cells. The decrease in electrical impedance of HUVEC monolayers in response to thrombin after TNF alpha treatment was also significantly reduced. However, the rise in [Ca2+]i in response to histamine was not altered by TNF alpha pretreatment. In conclusion, TNF alpha exposure of endothelial cells decreased both mRNA and protein expression of PATR, which explain the decreased activation of thrombin generated signals after the TNF alpha exposure.

[Methodology for controlling healthy worker effect on coal miners' mortality]

This paper reports how to control the healthy worker effect (HWE) in a mortality study of coal miners. We used four methods, namely (1) age-specific corrective coefficient, (2) proportional mortality ratio (PMR), (3) corrective standarized mortality ratio (CSMR), and (4) a control group composed of factory workers. The results showed that all these methods could control HWE, and the total mortality in the coal miner group was significantly higher than that of the general population group (P < 0.05). However, the best way for controlling HWE awaits further studies.

Removal of albumin microinjected in rat lung perimicrovascular space

We used a microinjection approach to assess hydraulic properties of lung perimicrovascular adventitia (interstitial cuff surrounding microvessels). Isolated blood-perfused rat lungs held at constant airway pressure were microscopically viewed to identify subpleural venules (20 microns diam). Venular adventitia were microinjected with 20 nl of fluorescent albumin (4 g/dl), and then adventitial fluorescence was quantified at the injection site by either photometery or imaging. Nonlinear decay of adventitial fluorescence indicated liquid flux from the injection site into normal interstitium. In some experiments, we determined that the adventitial fluorescence flowed longitudinally along the venule length and filled single lymphatics. The fluorescence decay at the injection site was best described by equations of convective but not diffusive transport. The decay time constant (time to 37% initial), which relates inversely to hydraulic conductivity, increased 10-fold above baseline on lung expansion with airway pressure from 5 to 15 cmH2O (P < 0.05). However, presence or absence of blood flow, increase in filtration pressure, and tissue edema were all without effect on the time constant. Our estimate of the lower limit of baseline adventitial hydraulic conductivity was 5 x 10(-6) ml.cm-2.s-1.cmH2O-1. We conclude that hydraulic conductivity of perimicrovascular adventitia is not augmented by edema but that it is decreased by lung expansion.

Albumin and Ricinus communis agglutinin decrease endothelial permeability via interactions with matrix

We studied the effects of albumin and the lectin Ricinus communis agglutinin (RCA) on hydraulic conductivity (Lp) of bovine pulmonary microvascular endothelial cell monolayers (BPMVEC) because of the evidence that albumin and RCA can interfere with transendothelial albumin permeability (Siflinger-Birnboim, A., J. Schnitzer, H. Lum, F. Blumenstock, C. Shen, P. Del Vecchio, and A. Malik. J. Cell. Physiol. 149: 575-584, 1991). BPMVEC were seeded on microporous polycarbonate filters, and the liquid flux was measured by collecting effluent into a tubing of known inner diameter at transendothelial hydrostatic pressures (P) ranging from 5 to 20 cmH2O. Lp was calculated as the slope of the relationship of liquid flux per unit surface area (Jv) vs. P. Addition of RCA (50 micrograms/ml) or albumin (5 mg/ml) to the endothelial cell medium containing albumin-free Hanks' balanced saline solution (HBSS) decreased total Lp (expressed x 10(-6) cm.s-1 x cmH2O-1) from 17.2 +/- 3.6 during HBSS to 4.7 +/- 0.9 during albumin and 5.7 +/- 1.6 during RCA (P < 0.01 for both). The RCA effect, but not that of albumin, was prevented by the addition of D-galactose (0.1 M) (the cognate hapten monosaccharide of RCA). We determined the contribution of the extracellular matrix (ECM) in decreasing the Lp by obtaining ECM after treatment of the monolayers with 0.025 M NH4OH to detach endothelial cells from the ECM. Basal ECM Lp (expressed x 10(-6) cm.s-1 x cmH2O-1) was 57.0 +/- 15.3, and it decreased to 19.7 +/- 4.3 and 17.5 +/- 2.9 during RCA and albumin, respectively (P < 0.01 for both). In contrast, RCA and albumin did not alter the filter Lp values. Another lectin, Ulex europaeus agglutinin, and the protein immunoglobulin G had no effect on Lp values.(ABSTRACT TRUNCATED AT 250 WORDS)