[S100A10 promotes proliferation and invasion of lung adenocarcinoma cells by activating the Akt-mTOR signaling pathway]

OBJECTIVE

To investigate the effects of expression levels of S100 calcium-binding protein A10 (S100A10) in lung adenocarcinoma (LUAD) on patient prognosis and the regulatory role of S100A10 in lung cancer cell proliferation and metastasis.

METHODS

Immunohistochemistry was used to detect the expression levels of S100A10 in LUAD and adjacent tissues, and the relationship between S100A10 expression and clinicopathological parameters and prognosis of the patients was statistically analyzed. The lung adenocarcinoma expression dataset in TCGA database was analyzed using gene enrichment analysis (GSEA) to predict the possible regulatory pathways of S100A10 in the development of lung adenocarcinoma. Lactate production and glucose consumption of lung cancer cells with S100A10 knockdown or overexpression were analyzed to assess the level of glycolysis. Western blotting, CCK-8 assay, EdU-594 assay, and Transwell assays were performed to determine the expression level of S100A10 protein, proliferation and invasion ability of lung cancer cells. A549 cells with S100A10 knockdown and H1299 cells with S100A10 overexpression were injected subcutaneously in nude mice, and tumor growth was observed.

RESULTS

The expression level of S100A10 was significantly upregulated in LUAD tissues as compared with the adjacent tissues, and an elevated S100A10 expression level was associated with lymph node metastasis, advanced tumor stage and distant organ metastasis (P < 0.05), but not with tumor differentiation or the patients' age or gender (P > 0.05). Survival analysis showed that elevated S100A10 expressions in the tumor tissue was associated with a poor outcome of the patients (P < 0.001). In the lung cancer cells, S100A10 overexpression significantly promoted cell proliferation and invasion in vitro (P < 0.001). GSEA showed that the gene sets of glucose metabolism, glycolysis and mTOR signaling pathway were significantly enriched in high expressions of S100A10. In the tumor-bearing nude mice, S100A10 overexpression significantly promoted tumor growth, while S100A10 knockdown obviously suppressed tumor cell proliferation (P < 0.001).

CONCLUSION

S100A10 overexpression promotes glycolysis by activating the Akt-mTOR signaling pathway to promote proliferation and invasion of lung adenocarcinoma cells.

Fluid shear stress-induced down-regulation of miR-146a-5p inhibits osteoblast apoptosis via targeting SMAD4

Fluid shear stress (FSS) plays an important role in osteoblast apoptosis. However, the role of miRNA in osteoblast apoptosis under FSS and possible molecular mechanisms remain unknown. Our aim of the study was to explore whether miR-146a-5p regulates osteoblast apoptosis under FSS and its molecular mechanisms. FSS could down-regulate the expression of miR-146a-5p in MC3T3-E1 cells. We confirm that up-regulation of miR-146a-5p promotes osteoblasts apoptosis and down-regulation of miR-146a-5p inhibits osteoblasts apoptosis. We further demonstrated that FSS inhibits osteoblast apoptosis by down-regulated miR-146a-5p. Dual-luciferase reporter assay validated that SMAD4 is a direct target gene of miR-146a-5p. In addition, mimic-146a-5p suppressed FSS-induced up-regulation of SMAD4 protein levels, which suggests that FSS elevated SMAD4 protein expression levels via regulation miR-146a-5p. Further investigations showed that SMAD4 could inhibit osteoblast apoptosis. We demonstrated that miR-146a-5p regulates osteoblast apoptosis via targeting SMAD4. Taken together, our present study showed that FSS-induced down-regulation miR-146a-5p inhibits osteoblast apoptosis via target SMAD4. These findings may provide novel mechanisms for FSS to inhibit osteoblast apoptosis, and also may provide a potential therapeutic target for osteoporosis.

The Therapeutic and Prognostic Role of Clusterin in Diverse Musculoskeletal Diseases: A Mini Review

This mini-review aims to introduce the association between Secretory clusterin/apolipoprotein J (sCLU) and diverse musculoskeletal diseases. A comprehensive review of the literature was performed to identify basic science and clinical studies, which implied the therapeutic and prognostic role of sCLU in diverse musculoskeletal diseases. sCLU is a multifunctional glycoprotein that is ubiquitously expressed in various tissues and is implicated in many pathophysiological processes. Dysregulated expression of sCLU had been reported to be assocaited with proliferative or apoptotic molecular processes and inflammatory responses, which participated in many pathophysiological processes such as degenerative musculoskeletal diseases including ischemic osteonecrosis, osteoarthritis (OA) and degenerative cervical myelopathy (spinal cord injury), neoplastic musculoskeletal diseases, inflammatory and autoimmune musculoskeletal diseases including Rheumatoid arthritis (RA), joint damage induced by Brucella abortus, Sjogren's syndrome, idiopathic inflammatory myopathies, muscle glucose metabolism, insulin sensitivity and traumatic musculoskeletal diseases. Recent findings of sCLU in these musculoskeletal diseases provides insights on the therapeutic and prognostic role of sCLU in these musculoskeletal diseases. sCLU may serve as a promising therapeutic target for ischemic osteonecrosis, OA and spinal cord injury as well as a potential prognostic biomarker for OA and RA. Moreover, sCLU could act as a prognostic biomarker for osteosarcoma (OS) and a promising therapeutic target for OS resistance. Although many studies support the potential therapeutic and prognostic role of sCLU in some inflammatory and autoimmune-mediated musculoskeletal diseases, more future researches are needed to explore the molecular pathogenic mechanism mediated by sCLU implied in these musculoskeletal diseases.

Fluid Shear Stress Promotes Osteoblast Proliferation and Suppresses Mitochondrial-Mediated Osteoblast Apoptosis Through the miR-214-3p-ATF4 Signaling Axis

MicroRNAs (miRNAs) play vital roles in bone metabolism and participate in the mechanically induced bone alterations. The underlying molecular mechanisms by which fluid shear stress (FSS) regulate the proliferative and apoptotic phenotypic changes of osteoblasts remain elusive. The study aimed to investigate the regulatory effects of FSS on osteoblast proliferative and apoptotic phenotypes and the roles of miR-214-3p-ATF4 (activating transcription factor 4) signaling axis in the mechanomodulation processes. FSS promoted the proliferative activity of osteoblasts and suppressed mitochondrial-mediated osteoblast apoptosis. FSS decreased miR-214-3p expression and increased ATF4 expression in MC3T3-E1 osteoblasts. MiR-214-3p inhibited osteoblast proliferative activity and promoted mitochondrial-mediated osteoblast apoptosis. Overexpression of miR-214-3p attenuated FSS-enhanced osteoblast proliferation and FSS-suppressed mitochondrial-mediated osteoblast apoptosis. We validated that ATF4 acted as a target gene of miR-214-3p. Moreover, miR-214 3p regulated osteoblast proliferation and apoptosis through targeting ATF4. Taken together, our study proved that FSS could suppress mitochondrial-mediated osteoblast apoptosis and promote osteoblast proliferation through the miR-214-3p-ATF4 signaling axis.

MiR-34a affects G2 arrest in prostate cancer PC3 cells via Wnt pathway and inhibits cell growth and migration

OBJECTIVE

To investigate the effect and mechanism of miRNA-34a overexpression on proliferation and migration of PC3 prostate cancer cells.

PATIENTS AND METHODS

Benign prostatic hyperplasia tissue (30 cases), prostate cancer tissue (30 cases), and prostate paracancerous tissue (30 cases) were collected. Levels of miRNA-34a in these fresh tissues were measured by fluorescence quantitative PCR. PC3 cells were divided into non-loaded group and overexpression group. Cells in the non-loaded group were transfected with non-loaded plasmid. Cells in the overexpression group were transfected with miRNA-34a plasmid, and the miRNA-34a level was determined by fluorescence quantitative PCR to confirm the overexpression. Cell proliferation was analyzed by CCK-8 assay. Cell migration rate was measured by cell scratch assay. Flow cytometry was used to detect apoptosis and analyze cell cycle. Western blot was used to measure the expression levels of β-catenin, E-cadherin and Vimentin.

RESULTS

The expression level of miRNA-34a in prostate cancer tissue was significantly lower than that in prostate paracancerous tissue. Dual-Luciferase reporter gene assay was used to analyze the transcriptional activity of Wnt1 gene. The proliferation and migration of PC3 cells were significantly decreased after overexpression of miRNA-34a, and the differences were statistically significant compared with those in the non-loaded group (p<0.05). Flow cytometry analysis showed that in the overexpression group, the apoptotic rate, as well as the proportion of cells in the G2 phase, was significantly higher than that in the non-loaded group (p<0.05). The β-catenin level in the nucleus of PC3 cells was significantly reduced after overexpression of miRNA-34a. The total protein levels of β-catenin and Vimentin were significantly decreased, whereas the level of E-cadherin in the overexpression group was apparently increased, compared with that in the non-loaded group. The Dual-Luciferase reporter gene showed a decrease in the relative fluorescence intensity of Wnt1 after overexpression of miR-34a (p<0.05).

CONCLUSIONS

Overexpression of miRNA-34a inhibits Wnt/β-catenin pathway by regulating the transcriptional activity of Wnt1, thereby regulating the proliferation and migration of PC3 cells and promoting apoptosis.

Management of Small Unruptured Intracranial Aneurysms: A Survey of Neuroradiologists

BACKGROUND AND PURPOSE

The long-term history and management of unruptured intracranial aneurysms is not well understood. Our aim was to determine current practice patterns in the management of unruptured intracranial aneurysms, especially regarding imaging surveillance for conservatively managed aneurysms of this type.

MATERIALS AND METHODS

An on-line survey was designed to examine physician practice and preference regarding the management of small unruptured intracranial aneurysms (≤7 mm in diameter). The survey was circulated to members of the American Society of Neuroradiology. Participation was voluntary, and all responses were anonymous.

RESULTS

A total of 227 individual survey responses were obtained and included in the analysis with 54.6% (124/227) from diagnostic neuroradiologists (practicing >50% neuroradiology) and one-third (29%) from neurointerventional radiologists. One hundred seventy-three of 227 responded that routine, periodic imaging surveillance would be appropriate for conservatively managed unruptured intracranial aneurysms, and 84% of respondents recommended surveillance frequency of at least once a year. Fifty-nine percent favored indefinite, life-long follow-up for small unruptured intracranial aneurysms, and a similar number of respondents favored noncontrast MR angiography for aneurysm follow-up. Significant heterogeneity was found in size measurements used to assess aneurysms and criteria used to define growth on surveillance imaging.

CONCLUSIONS

The natural history of intracranial aneurysms is not well-understood. A large proportion of incidentally detected, unruptured aneurysms are small (<7 mm). The survey results show significant heterogeneity in practice even among neuroradiologists and underlies the need to standardize imaging practice. Further studies are needed to assess the optimal frequency and duration of surveillance imaging for unruptured intracranial aneurysms. The criteria used to measure aneurysms and define growth on imaging also need to be standardized.

Evaluation of the Myo armband for the classification of hand motions

Pattern recognition-based control systems have been widely investigated in prostheses and virtual reality environments to improve amputees' quality of life. Most of these systems use surface electromyography (EMG) to detect user movement intentions. The Myo armband (MYB) is a wireless wearable device, developed by Thalmic Labs, which enables EMG recordings with a limited bandwidth (<100Hz). The aim of this study was to compare MYB's narrow bandwidth with a conventional EMG acquisition system (CONV) that captures the full EMG spectrum to assess its suitability for pattern recognition control. A crossover study was carried out with eight able-bodied participants, performing nine hand gestures. Six features were extracted from the data and classified by Linear Discriminant Analysis (LDA). Results showed a mean classification error of 5.82 ± 3.63% for CONV and 9.86 ± 8.05% for MYB with no significantly difference (P = 0.056). This implies that MYB may be suitable for pattern recognition applications despite the limitation in the bandwidth.

Large-size and high performance visible-light photodetectors based on two-dimensional hybrid materials SnS/RGO

We report a facile solvothermal method to synthesize two-dimensional hybrid materials consisting of layered SnS nanosheets and reduced graphene oxide (SnS/RGO). Large-size photodetectors with a channel length/width = 2 mm/7 mm are fabricated on Si/SiO₂ substrates, showing an excellent photoresponsivity of 0.18 A W⁻¹ under visible-light illumination with a detectivity of 4.18 × 10¹⁰ Jones, as well as fast rise and decay times (τ_rise = τ_decay = 0.4 s). SnS/RGO hybrids are therefore promising candidates for potential applications in optoelectronics and low cost, high performance, and reliable photodetectors.

We report a facile solvothermal method to synthesize hybrid materials SnS/RGO which are promising candidates for potential applications in photodetectors.

Facilitating the measurement of circulatory hydrogen sulfide with fluorescence probe-coated microplates

OBJECTIVE

The hydrogen sulfide (H₂S) role in pathogenesis of various diseases were wildly addressed in recent decade. The circulatory (plasma or serum) and biological fluid H₂S measurement is still an enormous issues due to the technical limitation. This paper aimed to develop a novel measurement method based on fluorescence probe.

METHODS

Firstly, 20 μL ethanol was used to dissolve 100 pmol fluorescence probe, then added in a 96-well plate. An equal volume of ethanol was also added to the blank well of the plate. The plate was placed in a dark room for about 1 h until the fluorescence probe was evenly coated in the 96-well microplate and dried. The plate was frozen at -20 °C for later use. Secondly, the plasma or serum sample was added with saturated ammonium sulfate buffer (pH 7.8) and then centrifuged to remove the proteins. The equal volume supernatant liquid was added to the probe-coated well and the probe-uncoated well. The plate was incubated in a dark environment at 37 °C for 2 h. Finally, after incubation, the fluorescence density was acquired at Λ_Ex/Λ_Em 340/445 nm in a microplate reader. The differences of the fluorescence density values between the probe-coated well and probe-uncoated well were counted and H₂S concentration of plasma/serum was calculated by standard curve with NaHS.

RESULTS

The method had high sensitivity (from 0.3 to 100 μmol/L) and specificity for measuring H₂S as compared with other biologically relevant reactive sulfur species and sulfur-containing amino acid. Serum H₂S concentrations were assayed in 188 health volunteers using this method [(12.1±3.5) μmol/L, 95%CI: 4.6-19.8 μmol/L], and the frequency distribution showed a normal tendency(one-sample Kolmogorov-Smirnov test, P>0.1). The serum H₂S concentrations in 30 hypertension patients were decreased compared with 22 age- and gender-matched health individuals (paired-samples t test, t=9.937, P<0.001). There were no differences of H₂S concentration in serum [(19.66±2.32) μmol/L] or plasma [(18.67±2.07) μmol/L], between the samples acquired from artery [(19.34±0.51) μmol/L] or vein [(18.99±0.50) μmol/L] of male Wistar rats (repeated measurement of ANOVA, P=0.38). One week frozen samples did not affect the detection. The values of the repeated measurement did not differ (two-way ANOVA, P>0.05).

CONCLUSION

The present method is easily performed with high sensitivity, specificity and repeatability for circulatory H₂S. It is also quick and may apply for large samples.

Polymer Adsorption on Graphite and CVD Graphene Surfaces Studied by Surface-Specific Vibrational Spectroscopy

Sum-frequency vibrational spectroscopy was employed to probe polymer contaminants on chemical vapor deposition (CVD) graphene and to study alkane and polyethylene (PE) adsorption on graphite. In comparing the spectra from the two surfaces, it was found that the contaminants on CVD graphene must be long-chain alkane or PE-like molecules. PE adsorption from solution on the honeycomb surface results in a self-assembled ordered monolayer with the C-C skeleton plane perpendicular to the surface and an adsorption free energy of ∼42 kJ/mol for PE(H(CH2CH2)nH) with n ≈ 60. Such large adsorption energy is responsible for the easy contamination of CVD graphene by impurity in the polymer during standard transfer processes. Contamination can be minimized with the use of purified polymers free of PE-like impurities.

Successful orthotopic liver transplantation in an adult patient with sickle cell disease and review of the literature

Sickle cell disease can lead to hepatic complications ranging from acute hepatic crises to chronic liver disease including intrahepatic cholestasis, and iron overload. Although uncommon, intrahepatic cholestasis may be severe and medical treatment of this complication is often ineffective. We report a case of a 37 year-old male patient with sickle cell anemia, who developed liver failure and underwent successful orthotopic liver transplantation. Both pre and post-operatively, he was maintained on red cell transfusions. He remains stable with improved liver function 42 months post transplant. The role for orthotopic liver transplantation is not well defined in patients with sickle cell disease, and the experience remains limited. Although considerable challenges of post-transplant graft complications remain, orthotopic liver transplantation should be considered as a treatment option for sickle cell disease patients with end-stage liver disease who have progressed despite conventional medical therapy. An extended period of red cell transfusion support may lessen the post-operative complications.

Electrical control of optical plasmon resonance with graphene

Surface plasmon has the unique capability to concentrate light into subwavelength volume. Active plasmon devices using electrostatic gating can enable flexible control of the plasmon excitations, which has been demonstrated recently in terahertz plasmonic structures. Controlling plasmon resonance at optical frequencies, however, remains a significant challenge because gate-induced free electrons have very weak responses at optical frequencies. Here we achieve efficient control of near-infrared plasmon resonance in a hybrid graphene-gold nanorod system. Exploiting the uniquely strong and gate-tunable optical transitions of graphene, we are able to significantly modulate both the resonance frequency and quality factor of gold nanorod plasmon. Our analysis shows that the plasmon-graphene coupling is remarkably strong: even a single electron in graphene at the plasmonic hotspot could have an observable effect on plasmon scattering intensity. Such hybrid graphene-nanometallic structure provides a powerful way for electrical control of plasmon resonances at optical frequencies and could enable novel plasmonic sensing down to single charge transfer events.

Graphene plasmonics for tunable terahertz metamaterials

Plasmons describe collective oscillations of electrons. They have a fundamental role in the dynamic responses of electron systems and form the basis of research into optical metamaterials. Plasmons of two-dimensional massless electrons, as present in graphene, show unusual behaviour that enables new tunable plasmonic metamaterials and, potentially, optoelectronic applications in the terahertz frequency range. Here we explore plasmon excitations in engineered graphene micro-ribbon arrays. We demonstrate that graphene plasmon resonances can be tuned over a broad terahertz frequency range by changing micro-ribbon width and in situ electrostatic doping. The ribbon width and carrier doping dependences of graphene plasmon frequency demonstrate power-law behaviour characteristic of two-dimensional massless Dirac electrons. The plasmon resonances have remarkably large oscillator strengths, resulting in prominent room-temperature optical absorption peaks. In comparison, plasmon absorption in a conventional two-dimensional electron gas was observed only at 4.2 K (refs 13, 14). The results represent a first look at light-plasmon coupling in graphene and point to potential graphene-based terahertz metamaterials.

The interaction of Li+ with single-layer and few-layer graphene

The interaction of Li(+) with single and few layer graphene is reported. In situ Raman spectra were collected during the electrochemical lithiation of the single- and few-layer graphene. While the interaction of lithium with few layer graphene seems to resemble that of graphite, single layer graphene behaves very differently. The amount of lithium absorbed on single layer graphene seems to be greatly reduced due to repulsion forces between Li(+) at both sides of the graphene layer.

Transfer-free batch fabrication of large-area suspended graphene membranes

We demonstrate a process for batch production of large-area (100-3000 microm(2)) patterned free-standing graphene membranes on Cu scaffolds using chemical vapor deposition (CVD)-grown graphene. This technique avoids the use of silicon and transfers of graphene. As one application of this technique, we fabricate transmission electron microscopy (TEM) sample supports. TEM characterization of the graphene membranes reveals relatively clean, highly TEM-transparent, single-layer graphene regions ( approximately 50% by area) and, despite the polycrystalline nature of CVD graphene, membrane yields as high as 75-100%. This high yield verifies that the intrinsic strength and integrity of CVD-grown graphene films is sufficient for sub-100 microm width membrane applications. Elemental analysis (electron energy loss spectroscopy (EELS) and X-ray energy-dispersive spectroscopy (EDS)) of the graphene membranes reveals some nanoscaled contamination left over from the etching process, and we suggest several ways to reduce this contamination and improve the quality of the graphene for electronic device applications. This large-scale production of suspended graphene membranes facilitates access to the two-dimensional physics of graphene that are suppressed by substrate interactions and enables the widespread use of graphene-based sample supports for electron and optical microscopy.

A tunable phonon-exciton Fano system in bilayer graphene

Fano resonances are features in absorption, scattering or transport spectra resulting from the interaction of discrete and continuum states. They have been observed in a variety of systems. Here, we report a many-body Fano resonance in bilayer graphene that is continuously tunable by means of electrical gating. Discrete phonons and continuous exciton (electron-hole pair) transitions are coupled by electron-phonon interactions, yielding a new hybrid phonon-exciton excited state. It may also be possible to control the phonon-exciton coupling with an optical field. This tunable phonon-exciton system could allow novel applications such as phonon lasers.

Synthesis and evaluation of a new series of peptide-based endothelin receptor antagonists

Novel peptide-based endothelin (ET) receptor antagonists were designed and synthesized in our laboratory. BQ-485, HIM-CO-Leu-d-Trp-d-Trp-OH, was selected as the leading compound. The primary structures of these new tripeptides were ABO-CO-Leu-d-Trp-d-AA(X)-OH. The introduction of unnatural aromatic amino acids into these tripeptides was useful in the structure-activity relationship studies. Among the 20 tripeptides, 16 of them showed high activities against the contraction of rat aortic smooth muscles induced by ET-1.

[Predictive value of peripheral artery ultrasonography for coronary artery disease]

OBJECTIVE

To investigate the diagnostic value of peripheral artery ultrasonography for coronary atherosclerotic disease (CAD).

METHODS

Peripheral artery ultrasonography was conducted among 135 consecutive examinees of coronary arteriography before the CAG. The results of peripheral artery ultrasonography and of coronary arteriography were analyzed with Stepwise multiple regression analysis and Logistic regression.

RESULTS

The incidence of atherosclerotic plaques of carotid, subclavicular, abdominal aortic, iliac and femoral arteries in patients with positive coronary arteriography was significantly higher than that in the subjects with negative coronary arteriography (P < 0.01); Logistic regression indicated that the presence of atherosclerotic plaques in femoral, abdominal aortic, and common iliac arteries was significantly closely correlated with CAD (P < 0.005, < 0.01, and < 0.05 respectively). Stepwise multiple regression analysis showed that common iliac IMT and femoral IMT were significant closely associated with the severity of coronary atherosclerosis (P < 0.0001). For each increased 1mm of iliac and femoral IMT, the LOG (1 + Gensini's score) of coronary arteriography increased by 0.227 and 0.219 respectively. The carotid artery IMT was partly associated with the LOG (1 + Gensini's score) of coronary arteriography (P < 0.05). The total score of extracoronary atherosclerosis (TSEcAS) was significantly correlated with the occurrence and severity of CAD (P < 0.0001). For 1 more extracoronary atherosclerotic plaques, the odds ratio and LOG (1 + Gensini's scores) for CAD increased 4.98 times and 0.323 respectively. Common iliac atherosclerosis was closely correlated with the occurrence of acute myocardial infarction. The positive predictive value of femoral, iliac atherosclerosis is 87.9%, 86.7%, 80.0% respectively; the positive predictive value for 2 and 3 sites of 3 above sites and is 88.6% and 94.9% respectively. Accuracy of discriminative function for positive and negative results and total was 91.5%, 93.8% and 92.5% respectively.

CONCLUSION

EcAS is closely correlated with CAD. It is possible to predict the occurrence, development, extent and severity of coronary artery atherosclerosis by extracoronary atherosclerosis. Common iliac atherosclerosis and femoral atherosclerosis are two independent factors closely correlated with the occurrence and progression of coronary atherosclerosis and can be used as the alternative indicators in study of coronary atherosclerosis.

[Effect of superoxide dismutase on membrane fluidity and functions of lymphocytes in traumatized mice]

Effect of superoxide dismutase (SOD) on membrane fluidity and functions of lymphocytes in traumatized mice was studied. The results showed that in vivo administration of SOD (10,000 U/kg.d, from 0 to 3 days posttrauma) could significantly decrease malondialdehyde (MDA) contents in serum, lymphatic tissues from spleen, thymus, mesenteric lymph nodes and T cells plasmalemma, mitochondria, microsome, restore decreased T lymphocytes and T cells in traumatized mice, elevate membrane fluidity of lymphocytes transformation (TLT), reduce interleukin 2 (IL-2) production, supprssed IL-2 receptor (IL-2R) expression and depress IL-2 mediated lymphocyte proliferation response (IL 2MLPR) after trauma in various degress. It is suggested that SOD may protect lymphocytes post trauma from damage of oxygen free radical, and elevate lymphocytes functions.

7-alkylidenecephalosporin esters as inhibitors of human leukocyte elastase

A series of 7-alkylidenecephalosporins and 7-vinylidenecephalosporins, as their benzhydryl esters, have been tested as inhibitors of both porcine pancreatic elastase and human leukocyte elastase. Selected 7-alkylidenecephalosporin esters are found to be potent inhibitors of HLE. One category of new inhibitors is the 7-(haloalkylidene)cephalosporins. In contrast to previously reported cephalosporin-based elastase inhibitors, these haloalkylidene cephems show optimum inhibitory activity as sulfides, rather than as sulfones. They are efficient and irreversible inhibitors. A second class of active compounds is represented by the benzhydryl ester 7-(cyanomethylidene)cephalosporin sulfone. In contrast to the activity of these new inhibitors, the benzhydryl ester of the mechanism-based beta-lactamase inhibitor, 7-[(2'-pyridyl)methylidene]-cephalosporin sulfone showed little inhibitory activity as an elastase inhibitor. 7-Vinylidenecephalosporins were also relatively poor inhibitors, although the terminally unsubstituted allene sulfide showed activity as an inhibitor of PPE. A modeling analysis suggests the 7-alkylidene substituents can be readily accommodated in the S1 pocket. A potential mechanism of inhibition is proposed.

[Effects of Astragalus polysaccharides and ginsenosides of Ginseng stems and leaves on lymphocytes membrane fluidity and lipid peroxidation in traumatized mice]

From days 0 to 3 posttrauma, daily administration of Astragalus polysaccharides (250mg/kg,ip) and ginsenosides of ginseng stems and leaves (50mg/kg,sc) can elevate significantly the lymphocytes membrane fluidity of plasmalemma, mitochondria and microsome from spleen,thymus and mesenteric lymph nodes in traumatized mice, reduce lipid peroxide levels, and increase superoxide dismutase activities in serum and lymphocytes from traumatized mice.

[Changes in free calcium concentration and protein kinase C activity in activated T cells of burn mice and their significance]

TBSA 10%III degrees burn mice model was used. The changes in free calcium concentration ([Ca2+]i) and protein kinase C (PKC) activity in activated T cells from burn mice, and their relationship with T cell functions was studied. The results showed that [Ca2+]i and PKC activity in activated T cells were reduced after burn and these changes were closely related to reduced interleukin 2(IL-2) mRNA and IL-2 receptor alpha (IL-2R alpha) mRNA levels, decreased IL-2 production, suppressed IL-2R alpha expression, reduced T lymphocytes transformation in T cells of burn mice. Calcium cation ionophore A 23187 and PKC activator TPA could in vitro elevate respectively [Ca2+]i and PKC activity in activated T cells of burn mice. They also increased significantly IL-2 and IL-2R alpha gene expression in T cells of burn mice, but not up to the normal control. It is suggested that reduced [Ca2+]i, PKC activity in activated T cells may be one of the causes which produce suppression of T cell functions after burns.

[The effect of astragalus polysaccharides (APS) on cell mediated immunity (CMI) in burned mice]

In this paper, the changes in CMI in mice were determined after burn injury, and the effects of APS on CMI of burned mice were investigated in vivo. The results showed that on day 6 postburn, spleen index and thymus index were reduced, T lymphocyte transformation and interleukin 2 (IL-2) production were suppressed. Furthermore, the serum and macrophages from burned mice showed significant suppressive activity upon T lymphocyte transformation in vitro, and suppressive index (SI) of suppressor T cell (Ts) was greater than that of normal controls. Intraperitoneal administration of APS (250mg/kg daily, from day 0 to 5 could restore spleen index and thymus index of burned mice, reverse the suppression of T lymphocyte transformation and IL-2 production, reduce remarkably the suppressive activity of serum, macrophages and Ts. It is suggested that (1) burn injury-induced suppression of CMI may be related to the augmented suppressive activity of serum, macrophages and Ts; (2) administration of APS may restore the impaired CMI after burn injury by reducing the suppressive activity of postburn serum, macrophages and Ts.