TRAF4 regulates ubiquitination-modulated survivin turnover and confers radioresistance

Nasopharyngeal carcinoma (NPC) is the most common cancer originating in the nasopharynx. Despite continuous improvement in treatment strategies, recurrence or persistence of cancer after radiotherapy is still inevitable, highlighting the need to identify therapeutic resistance factors and develop effective methods for NPC treatment. Herein, we found that TRAF4 is overexpressed in NPC cells and tissues. Knockdown TRAF4 significantly increased the radiosensitivity of NPC cells, possibly by inhibiting the Akt/Wee1/CDK1 axis, thereby suppressing survivin phosphorylation and promoting its degradation by FBXL7. TRAF4 is positively correlated with p-Akt and survivin in NPC tissues. High protein levels of TRAF4 were observed in acquired radioresistant NPC cells, and knockdown of TRAF4 overcomes radioresistant in vitro and the xenograft mouse model. Altogether, our study highlights the TRAF4-survivin axis as a potential therapeutic target for radiosensitization in NPC.

Survivin degradation by bergenin overcomes pemetrexed resistance

PURPOSE

Chemoresistance is a primary factor for treatment failure and tumor recurrence in non-small cell lung cancer (NSCLC) patients. The oncoprotein survivin is commonly upregulated in human malignancies and is associated with poor prognosis, but its effect on carcinogenesis and chemoresistance in NSCLC is not yet evident, and to explore an effective inhibitor targeting survivin expression is urgently needed.

METHODS

The protumor characteristics of survivin and antitumor activities of bergenin in NSCLC cells were examined by MTS, colony formation assays, immunoblot, immunohistochemistry, and in vivo xenograft development.

RESULTS

Survivin was upregulated in non-small cell lung cancer (NSCLC) tissues, while its depletion inhibited NSCLC tumorigenesis. The current study focused on bergenin, identifying its effective antitumor effect on NSCLC cells both in vivo and in vitro. The results showed that bergenin could inhibit cell proliferation and induce the intrinsic pathway of apoptosis via downregulating survivin. Mechanistically, bergenin reduced the phosphorylation of survivin via inhibiting the Akt/Wee1/CDK1 signaling pathway, thus resulting in enhanced interaction between survivin and E3 ligase Fbxl7 to promote survivin ubiquitination and degradation. Furthermore, bergenin promoted chemoresistance in NSCLC cells re-sensitized to pemetrexed treatment.

CONCLUSIONS

Survivin overexpression is required for maintaining multiple malignant phenotypes of NSCLC cells. Bergenin exerts a potent antitumor effect on NSCLC via targeting survivin, rendering it a promising agent for the treatment of NSCLC.

Hypoxia is correlated with the tumor immune microenvironment: Potential application of immunotherapy in bladder cancer

OBJECTIVE

Hypoxia, which can considerably affect the tumor microenvironment, hinders the use of immunotherapy in bladder cancer (BLCA). Therefore, we aimed to identify reliable hypoxia-related biomarkers to guide clinical immunotherapy in BLCA.

METHODS

Using data downloaded from TCGA-BLCA cohort, we determined BLCA subtypes which divide 408 samples into different subtypes. Tumor immune infiltration levels of two clusters were quantified using ssGSEA, MCPcounter, EPIC, ESTIMATE, and TIMER algorithms. Next, we constructed a hypoxia score based on the expression of hypoxia-related genes. The IMvigor210 cohort and SubMap analysis were used to predict immunotherapeutic responses in patients with different hypoxia scores. Hub genes were screened using cytoscape, immunohistochemistry (IHC), and multispectral immunofluorescence were used to detect the spatial distribution of immune markers.

RESULTS

Patients with BLCA were categorized into cluster1 (n = 227) and Cluster2 (n = 181). Immune infiltration and expression of immune markers were higher in Cluster1. Immune infiltration was also more obvious in the high-hypoxia score group which related to a better predicted response to immunotherapy. IHC, and multispectral immunofluorescence confirmed the importance of TLR8 in immune infiltration and immune phenotype.

CONCLUSIONS

BLCA subtype can evaluate the infiltration of immune cells in the tumor microenvironment of different patients. Hypoxia score in this study could effectively predict immunotherapeutic responses in patients with BLCA. TLR8 may be a potential target for clinical immunotherapy.

Integrative taxonomy and phylogenetic relationships between representatives of genera within Merliniinae (Nematoda: Merliniidae), with new data on fourteen known and one unknown species

The application of integrative taxonomic approaches is useful to species delineation based on a combination of distinct types of characters, here morphological features and ribosomal DNA sequences. In this study, we surveyed ectoparasitic nematodes of the subfamily Merliniinae in cultivated and natural environments in Iran. Results of morphological and morphometrical studies, light and scanning electron microscopic observations, and molecular analyses allowed us the identification of fourteen known and one unknown species including representatives of the genera Amplimerlinius (five species), Geocenamus (one species), Merlinius (three species), Nagelus (two species), Paramerlinius (one species), Scutylenchus (two species), and Telomerlinius (one species). The unknown species, Scutylenchus sp., characterized by having 35-50 incisures at mid-body; lateral field with 6 longitudinal incisures; lip region slightly offset by a constriction, flattened at front end; bearing 5-7 annuli; cephalic framework not refractive; stylet robust, 18.3-27 μm long; post anal intestinal sac absent; tail elongate conical, dorsally convex, with 24 (19-28) annuli in ventral side, ending to a smooth terminus and males common; spicules 24.5-31 μm long. The phylogenetic analyses were carried out using molecular data from nuclear ribosomal DNA (rDNA) genes viz. D2-D3 expansion segments of the large ribosomal subunit (28S rRNA), partial small ribosomal subunit (18S rRNA), and internal transcribed spacer (ITS). The molecular variability of D2-D3 expansion segments of the 28S rRNA and partial 18S rRNA was low in this family in comparison to the ITS region, which could be a more helpful molecular marker in species and genus identification.

Gastrodin destabilizes survivin and overcomes pemetrexed resistance

Survivin is a bifunctional protein that plays crucial roles in tumorigenesis. In the present study, we discovered that the natural product gastrodin suppressed the cell viability and colony formation of non-small cell lung cancer (NSCLC) cell lines A549, HCC827, and H460 in a dose-dependent manner. In addition, gastrodin enhanced the protein levels of cleaved-caspase 3 by activating the endogenous mitochondrial apoptosis pathway. Gastrodin inhibits protein kinase B (Akt)/WEE1/cyclin-dependent kinase 1 (CDK1) signaling to downregulate survivin Thr34 phosphorylation. Survivin Thr34 dephosphorylation caused by gastrodin interfered with the binding of ubiquitin-specific protease 19 (USP19), which eventually destabilized survivin. We revealed that the growth of NSCLC xenograft tumors was markedly suppressed by gastrodin in vivo. Furthermore, gastrodin overcomes pemetrexed resistance in vivo or in vitro. Our results suggest that gastrodin is a potential antitumor agent by reducing survivin in NSCLC.

Bergenin Inhibits Tumor Growth and Overcomes Radioresistance by Targeting Aerobic Glycolysis

Hexokinase 2 (HK2), the first glycolytic rate-limiting enzyme, is closely correlated with the occurrence and progression of tumors. Effective therapeutic agents targeting HK2 are urgently needed. Bergenin has exhibited various pharmacological activities, such as antitumor properties. However, the effects of bergenin on the abnormal glucose metabolism of cancer cells are yet unclear. In this study, HK2 was overexpressed in OSCC tissues, and the depletion of HK2 inhibited the growth of OSCC cells in vitro and in vivo. Moreover, these results showed that the natural compound, bergenin, exerted a robust antitumor effect on OSCC cells. Bergenin inhibited cancer cell proliferation, suppressed glycolysis, and induced intrinsic apoptosis in OSCC cells by downregulating HK2. Notably, bergenin restored the antitumor efficacy of irradiation in the radioresistant OSCC cells. A mechanistic study revealed that bergenin upregulated the protein level of phosphatase and the tensin homolog deleted on chromosome 10 (PTEN) by enhancing the interaction between PTEN and ubiquitin-specific protease 13 (USP13) and stabilizing PTEN; this eventually inhibited AKT phosphorylation and HK2 expression. Bergenin was identified as a novel therapeutic agent against glycolysis to inhibit OSCC and overcome radioresistance. Targeting PTEN/AKT/HK2 signaling could be a promising option for clinical OSCC treatment.

Transcriptomics of Cruznema velatum (Nematoda: Rhabditidae) with a redescription of the species

Cruznema velatum isolated from soil in a chestnut orchard located at Guangdong province, China, is redescribed with morphology, molecular barcoding sequences, and transcriptome data. The morphological comparison for C. velatum and six other valid species is provided. Phylogeny analysis suggests genus Cruznema is monophyletic. The species is amphimix, can be cultured with Escherichia coli in 7-9 days from egg to egg-laying adult, and has a lifespan of 11 to 14 days at 20°C. The transcription data generated 45,366 unigenes; 29.9%, 31.3%, 24.8%, and 18.6% of unigenes were annotated in KOG, SwissProt, GO, and KEGG, respectively. Further gene function analysis demonstrated that C. velatum share the same riboflavin, lipoic acid, and vitamin B6 metabolic pathways with Caenorhabditis elegans and Pristionchus pacificus.

Analysis on Recycling Channel Selection of Construction and Demolition Waste in China from the Perspective of Supply Chain

Although construction and demolition waste (C&D waste) recycling has been widely regarded as an effective way to save resources, its selection of recycling channels has received little attention. In order to improve the recycling efficiency of C&D waste and promote the process of C&D waste management, we innovatively propose a dual-channel recycling problem of C&D waste from the perspective of supply-chain operation, aiming to study the impact of the selection of recycling channels and the government’s economic intervention on pricing decisions. Specifically, we build in this paper a three-echelon construction material supply chain including a construction contractor, a professional recycling agency, and a building materials manufacturer, considering two modes: the construction contractor does the recycling job alone (as the direct channel) and the construction contractor entrusts the recycling job to the professional recycling agency (as the indirect channel). We use game theory to analyze the optimal decision strategies of the members with or without governmental intervention and the equilibrium strategies are obtained. At the same time, taking Chongqing city as an example, we apply the model to carry out numerical simulation, and the results reveal that greater recycling costs of C&D waste leads to lower profits for the members. When the market capacity of first-class renewable building materials increases, the recycler’s recycling cost of C&D waste decreases, and the remanufacturing cost of recycled materials processed into first-class renewable building materials decreases, the supply-chain members will choose the indirect channel to perform the recycling job. In the case when government intervention exists, the recycling quantity of C&D waste increases, the price of the final products decreases, and both the total profit of the system and the profit of the supply-chain members increase; there is a positive correlation with the government subsidies. The study provides some insights on managerial significance to C&D waste recycling management.

[Effect of endoscopic vidian neurectomy in patients with coexisting allergic rhinitis and bronchial asthma]

Objective: To evaluate the clinical significance of endoscopic vidian neurectomy (EVN) on outcomes in patients with coexisting refractory allergic rhinitis (AR) and bronchial asthma, and to analyze its influence factor. Methods: Clinical data of 109 patients with moderate to severe persistent intractable AR and bronchial asthma who were allocated to the bilateral EVN group (surgery group, 70 cases) or conservative medication group (drug group, 39 cases) from 1 May 2008 to 30 April 2013 in Department of Otorhinolaryngology Head and Neck Surgery, Third Xiangya Hospital, Central South University were retrospectively analyzed, including 47 cases of male and 62 cases of female aged (32.7±6.8) years.Ninety-five patients were followed up for at least 3 years. The Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), Visual Analog Scale (VAS), Asthma Quality of Life Questionnaire (AQLQ), Total Asthma Symptom Score (TASS), forced expiratory volume in 1 second of predicted (FEV1) and medication scores were evaluated at 6 months, 1 year and 3 years after undergoing the initial treatments in the two groups. Multiple factor analysis was used to determine the factors influencing the improvement after EVN. Results: Postoperative scores of RQLQ were significantly lower than preoperative scores during follow-up in surgery group (the preoperative score and postoperative score at 6 months, 1 year, 3 years after operation was 2.39±0.61 (x±s), 0.81±0.43, 0.89±0.32, 1.06±0.24, respectively, all P<0.001). Postoperative scores of VAS were significantly lower than preoperative scores during follow-up in surgery group (the preoperative score and postoperative score at 6 months, 1 year,3 years after operation was 7.13±1.04, 2.52±1.47, 2.70±1.42, 2.85±1.64, respectively, all P<0.05). Scores of RQLQ and VAS in surgery group were significantly lower than those of drug group. Postoperative scores of AQLQ were significantly higher than preoperative scores during follow-up in surgery group (the preoperative score and postoperative score at 6 months, 1 year, 3 years after operation was 3.78±0.81, 4.99±0.45, 4.75±0.71, 4.62±0.64, respectively, all P<0.05), and were significantly higher than those of drug group. The TASS and FEV1 were not significantly changed in surgery group. The postoperative medication scores for AR were gradually reduced after surgery (the preoperative score and postoperative score at 6 months, 1 year, 3 years after operation was 0.99±0.21, 0.37±0.12, 0.39±0.26, 0.45±0.11, respectively, all P<0.05), and the postoperative medication scores for Asthma were gradually reduced after surgery too (the preoperative score and postoperative score at 6 months, 1 year, 3 years after operation was 1.27±0.31, 0.82±0.29, 0.85±0.23, 0.96±0.19, respectively, all P<0.05), and all the postoperative medication scores were significantly lower than those of drug group. At the end of the follow-up, the improvement rates for AR and asthma were 90.6% (58/64) and 45.3% (29/64), respectively. Asthma outcomes were significantly improved by controlling rhinitis symptoms in patients whose asthma attacks were induced by "rhinitis onset" or "climate change" . Conclusion: For patients with AR and bronchial asthma, EVN can significantly control AR symptoms, and improve asthma outcomes in patients whose asthma attacks are induced by rhinitis onset and/or climate change.

Transcription factor STAT1 promotes the proliferation, migration and invasion of nasopharyngeal carcinoma cells by upregulating LINC01160

Aim: To investigate the role of LINC01160 in nasopharyngeal carcinoma (NPC). Materials & methods: Using NPC cells CNE-2 and HNE-2 in vitro, we performed quantitative PCR to determine mRNA expression and western blotting to determine protein expression. CCK-8, transwell, flow cytometry and wound healing assays were done to examine the function of LINC01160 and STAT1. Chromatin immunoprecipitation PCR (ChIP-PCR) confirmed that STAT1 combines with the LINC01160 promoter region. Xenograft experiments were used to verify the role of STAT1 and LINC01160 in vivo. Results: LINC01160 is upregulated in NPC and can promote a malignant cell phenotype. STAT1 is a transcription factor of LINC01160 and can promote a malignant cell phenotype through upregulating LINC01160 expression. Conclusion: STAT1 can promote a malignant cell phenotype by upregulating LINC01160.

LINC00669 insulates the JAK/STAT suppressor SOCS1 to promote nasopharyngeal cancer cell proliferation and invasion

Nasopharyngeal carcinoma (NPC) is an epithelial cancer emerging from the lining of nasopharyngeal mucosa, with extremely frequent occurrence in east and southeast Asia. For the purpose of exploring roles of the dysregulated long non-coding RNA (lncRNA) in NPC, we identified a novel lncRNA LINC00669 with an apparent negative correlation to the overall survival from human NPC mRNA expression profiling databases. We further performed RNA pulldown coupled with mass spectrum to find out its target protein, and applied a series of in vitro and in vivo loss-and-gain-of function assays to investigate its oncogenic roles in NPC tumor development and progression. Our results demonstrated that LINC00669 competitively binds to the key JAK/STAT signaling pathway suppressor SOCS1, and insulates it from imposing ubiquitination modification on the pathway component of STAT1, which leads to its abnormal stabilization and activation. The activated STAT1 is then transferred into the nucleus and initiates the transcription of genes related to proliferation and invasion. In summary, our study reveals that the cytoplasmic resident lncRNA LINC00669 confers malignant properties on NPC cancer cells by facilitating a persistent activation of the JAK/STAT signaling pathway. Findings in the current study shed lights on prospects for treating NPC using strategies targeting the novel regulator of the JAK/STAT signaling.

Mir-142-3p Regulates Inflammatory Response by Contributing to Increased TNF-α in Chronic Rhinosinusitis With Nasal Polyposis

Objective:

Previous studies suggested that microRNAs played an important role in the progression of inflammation and remodeling of chronic rhinosinusitis with nasal polyposis. However, the abnormal expression of microRNAs and regulation cytokine expression in nasal polyposis are not clear.

Method:

The miR-142-3p and tumor necrosis factor α (TNF-α) expression levels in chronic rhinosinusitis with nasal polyposis were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The miR-142-3p and TNF-α levels in human nasal epithelial cells (HNEpC) after stimulation by lipopolysaccharide (LPS) were detected by qRT-PCR. Moreover, HNEpCs were transfected by miR-142-3p mimics or inhibitor or cotransfected with si-TNF-α to evaluate the regulation of miR-142-3p on TNF-α which affects the production of inflammatory factors.

Results:

The miR-142-3p and TNF-α were significantly higher in nasal mucosa of chronic rhinosinusitis with polyps patients compared to normal human. MiR-142-3p and TNF-α expression levels were increased after LPS stimulation in a dose- and time-dependent manner. Knockdown of miR-142-3p in HNEpCs downregulated TNF-α expression at both messenger RNA and protein levels.

Conclusions:

It is indicated that miR-142-3p may participate in the regulation of the body’s inflammatory response through the LPS-TLR-TNF-α signaling pathway in chronic rhinosinusitis with nasal polyposis.

Clinical Effect of Endoscopic Vidian Neurectomy on Bronchial Asthma Outcomes in Patients with Coexisting Refractory Allergic Rhinitis and Asthma

Background The prevalence of both allergic rhinitis and bronchial asthma is high throughout the world; their mutual influence on each other has been documented in many studies. However, studies regarding surgical intervention are limited. Objective To evaluate the clinical significance of endoscopic vidian neurectomy on bronchial asthma outcomes in patients with coexisting refractory allergic rhinitis and asthma. Methods A total of 109 patients with moderate to severe persistent intractable allergic rhinitis and mild/moderate asthma were allocated to the bilateral endoscopic vidian neurectomy group (group 1) or conservative medication group (group 2) according to the patients' self-selection. The Rhinoconjunctivitis Quality of Life Questionnaire, Visual Analog Scale, Asthma Quality of Life Questionnaire, Total Asthma Symptom Score, and medication scores were evaluated at six months, one year, and three years after undergoing the initial treatments. Multivariate analysis was performed to determine which triggers of asthma attacks were associated with improved asthma outcomes in patients. Results Ninety-five patients were followed up for at least three years. Postoperative scores of Rhinoconjunctivitis Quality of Life Questionnaire and Visual Analog Scale were significantly lower than preoperative scores during follow-up in group 1 and were significantly lower than those of group 2. Postoperative scores of Asthma Quality of Life Questionnaire at the three follow-up time points were higher than the preoperative scores in group 1. The Total Asthma Symptom Score was not significantly decreased in group 1. The medication scores for allergic rhinitis and asthma were gradually reduced after surgery. At the end of the follow-up, the improvement rates for allergic rhinitis and asthma were 90.6% and 45.3%, respectively. Asthma outcomes were significantly improved by controlling rhinitis symptoms in patients whose asthma attacks were induced by "rhinitis onset" or "weather change." Conclusion Controlling allergic rhinitis symptoms by bilateral endoscopic vidian neurectomy can significantly improve asthma outcomes in patients whose asthma attacks are induced by rhinitis onset and/or cold air.

Kinetics of the endocytotic pathway of Low Density Lipoprotein (LDL) in human endothelial cells line under shear stress: an in vitro confocal microscopy study

We studied the effect of mechanical forces (shear stress) on the kinetics of internalization of native LDL and ox-LDL in endothelial cell line ECV304. This study was performed by using Confocal microscopy and FRET with two carbocyanine dyes, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiO) as the donor and 3,3'-dioctadecyloxacarbocyanine perchlorate (DiI) as the receptor. The cells were incubated with a culture medium containing either 10 microg/ml DiI-LDL or DiO-LDL in static conditions or subjected to a laminar flow under a Confocal Laser Scanning Microscope (SP2 Leica, Germany). The results showed: (1) the possibility to evaluate the kinetics of LDL endocytosis in living cells, (2) shear stress in comparison with control group more effectively enhanced LDL uptake, (3) ox-LDL (>50 microg/ml) >4 hours incubation was found to affect the cells as reflected by their detachment at low shear stress.

Antigenic triggers and molecular targets for anti-double-stranded DNA antibodies

While anti-double-stranded (ds)DNA antibodies are a characteristic serologic hallmark for SLE, the triggering antigen is unknown. Using phage display libraries, we identified DWEYSVWLSN as a peptide mimic of DNA for a pathogenic anti-dsDNA antibody. Peptide immunization of non-autoimmune mice induced anti-dsDNA as well as other lupus-associated antibodies. Molecular analysis of the induced anti-dsDNA antibodies revealed several similarities with anti-dsDNA antibodies that appear spontaneously in lupus mice. Furthermore, lupus-prone mice immunized with this peptide DNA mimic had higher autoantibody titers as well as more severe nephritis. Anti-DNA antibodies may contribute to lupus nephritis via cross-reactivity with renal antigen. Using western blotting of lysates of mesangial cells from a lupus mouse, we found that a pathogenic anti-DNA antibody binds to alpha-actinin. High titers of anti-alpha-actinin antibodies were present in the sera and kidney eluates of lupus mice with active disease. Binding to alpha-actinin was diminished in mesangial cells derived from BALB/c mice, suggesting that target antigen expression may play a role in determining autoantibody binding to the kidney. We conclude that a pathogenic, lupus-like autoantibody response can be induced by a peptide antigen, and that alpha-actinin is a cross-reactive renal target for the pathogenic anti-dsDNA autoantibody response in lupus mice.

[Modulation of endothelin-1 on pulmonary surfactant synthesis of cultured alveolar type II cells]

The effects of endothelin-1(ET-1) on pulmonary surfactant(PS) synthesis of cultured AT II cells were observed. The results showed that: 1. ET-1(10(-11)-10(-8) mol.L-1) enhanced PS synthesis of cultured AT II cells in a dose-dependent manner. 2. The minimum effective concentration of ET-1 enhanced PS synthesis of cultured AT II cells was higher than that of lung explants. 3. ETA antagonist BQ123 decreased the effect of ET-1 on PS synthesis, but ETB antagonist BQ788 did not change the effect. 4. ET-1 (10(-12) and 10(-10) mol.L-1) had no effect on the proliferation of AT II cells. These results confirmed that ET-1 can enhance directly and indirectly on the PS synthesis of AT II cells mediated via ETA receptor. The effect of ET-1 on PS synthesis was not induced by changing the number of AT II cells.

mRNA expression of novel CGRP1 receptors and their activity-modifying proteins in hypoxic rat lung

Calcitonin gene-related peptide (CGRP) is a potent vasodilator. Our group has reported that exogenous CGRP may prevent or reverse hypoxic pulmonary hypertension in rats. The vasodilatory action of CGRP is mediated primarily by CGRP1 receptors. The calcitonin receptor-like receptor (CRLR) and the orphan receptor RDC-1 have been proposed as CGRP1 receptors, and recent evidence suggests that CRLR can function as either a CGRP1 receptor or an adrenomedullin (ADM) receptor. Receptor activity-modifying proteins (RAMPs) determine the ligand specificity of CRLR: coexpression of CRLR and RAMP1 results in a CGRP1 receptor, whereas coexpression of CRLR and RAMP2 or -3 results in an ADM receptor. We used qualitative, semiquantitative, and real-time quantitative RT-PCR to detect and quantitate the relative expression of these agents in the lungs of rats exposed to normoxia (n = 3) and 1 and 2 wk of chronic hypobaric hypoxia (barometric pressure 380 mmHg, equivalent to an inspired O(2) level of 10%; n = 3/time period). Our results show upregulation of RDC-1, RAMP1, and RAMP3 mRNAs in hypoxic rat lung and no change in CRLR and RAMP2 mRNAs. These findings support a functional role for CGRP and ADM receptors in regulating the adult pulmonary circulation.

Influence of overlying tissue and probe geometry on the sensitivity of a near-infrared tissue oximeter

In this paper, the influences of overlying tissue and detecting distance between the source and the detector on the measurement of a tissue oximeter were discussed. The signal-noise-ratio of the detector was also examined. A semi-infinite multi-layer Monte Carlo model was induced to simulate the migration of the photons in the skin, adipose and muscle. The thickness of the adipose layer and the separation between the source and the detector in the muscle were changed to simulate the clinical application. Partial pathlength was introduced as a characteristic parameter to evaluate the sensitivity of the oximeter. A two-wavelength (700 and 830 nm) tissue oximeter was developed to verify the results of the simulation. The Monte Carlo simulation results showed that the sensitivity of the near infrared spectroscopy (NIRS) oximeter declined greatly with increasing overlying tissue thickness. Increasing the distance between the light source and the detector improved the sensitivity. However, in order to achieve a sufficiently high signal-to-noise ratio, it was necessary to limit this distance. The results of a bicycle ergometer exercise verified the above results and showed that, for a special adipose thickness (AT), there may be a reasonable range of the emitter-detector separation.

[Modulation of endothelin-1 on pulmonary surfactant synthesis in lung explants]

The effect of endothelin-1(ET-1) on pulmonary surfactant(PS) synthesis was studied in cultured lung explants without serum. The results showed that: 1. ET-1 increased [3H] choline incorporation with dose-dependence and time-dependence. 10(-10) mol.L-1 ET-1 increased the contents of total phospholipids, phosphatidylcholine and phosphatidylglcerol in lung tissues. The major membrane characteristic phospholipids, such as phosphatidylethanolamine, phosphatidylinostitol, phosphatidylserine and sphingomyelin, did not show changes. 2. BQ123, a ETA receptor selective antagonist, could decline the [3H] choline incorporation induced by ET-1(10(-12) and 10(-10) mol.L-1) (P < 0.01). 3. PMA, a protein kinase C(PKC) activator, increased [3H] choline incorporation into lung tissues (P < 0.01); the PKC inhibitor H7 decreased [3H] choline incorporation induced by ET-1(P < 0.01). The results demonstrated that ET-1 at physiological level can enhance the PS synthesis mediated by ETA receptor and PKC.

Left ventricular diastolic dysfunction in patients with angina decubitus

OBJECTIVE

To investigate the relationship between left ventricular diastolic dysfunction and episodes of angina decubitus.

METHODS

The study population consisted of three groups, groups I (20 controls) had no cardiovascular diseases. Group II (20 patients) had coronary artery disease (CAD) without angina decubitus. Group III (24 cases with ejection fraction (EF) > 45%) were selected from 26 patients with angina decubitus.

RESULTS

Left ventriculography (LVG) showed that left ventricular (LV) first 1/3 filling fraction (1/3FF) was significantly reduced in groups III as compared with groups II and I (P < 0.01). Left ventricular end-diastolic pressure (LVEDP) significantly increased in patients with angina decubitus after LVG as compared with that before LVG (P < 0.01). However, there were no statistically differences in LVEDP, before and after LVG in both groups II and I.

CONCLUSIONS

Patients with angina decubitus have abnormalities of LV diastolic filling and decrease in LV compliance.

[Clinical and angiographic characteristics of renovascular hypertension]

Clinical and angiographic characteristics of renovascular hypertension were studied in 95 patients. The patients were divided into 3 groups: 55 cases with aortic arteritis (group AA), 27 with fibromuscular dysplasia (group FMD) and 9 with atherosclerosis (group AS). The patients in group AS were significantly older in age and had longer history of hypertension. Abdominal bruit was heard significantly more often in group AA and serum potassium was significantly lower in group FMD. Angiographic data showed that in group AA lesions in thoracic aorta and abdominal aorta was found in 81.4% and those involving both renal arteries in 52.5%. In group FMD, 82.5% of patients had lesion in renal artery on one side and none had lesion in thoracic and abdominal aorta. In group AS, lesions were found mainly in thoracic and abdominal aorta, accounting for 77.7% and lesions in renal arteries were mainly unilateral. In group AA, lesions were found in 90 renal arteries altogether. Among them, 58.9% was in the proximal part of the renal artery; the lesion was either localized stenosis (67.8%) or obstruction (17.7%). In group FMD, lesions were found in 33 renal arteries altogether. Among them, 48.5% was in the middle or distal part of the renal artery and 27.3% resembled string of beads. In group AS, a total of 10 renal arteries were involved with 4 (40%) of ostial stenosis and 4 (40%) total obstruction.

Optical fringe multiplication in moiré interferometry

An optical method for multiplication of moiré fringes is proposed to increase the sensitivity of moireé interferometry. The process involves two recording steps. In the first step, a traditional moiré interferometry setup is used. The moiré pattern containing carrier fringes and load fringes is recorded onto a glass-based holographic plate. The carrier frequency is much lower than that of the original specimen grating. The plate is then developed. In the second step, the holographic plate, regarded as a distorted specimen grating, is further examined by a similar moiré interferometry system. The frequency of the second virtual grating is arranged to be 2n times that of the carrier fringes contained in the recorded plate. As a result, the load fringes are revealed with a multiplication factor of 2n. The interpretation of the optical multiplication method from wave-front interference theory is given and an experiment is conducted.