[Heparin-binding hemagglutinin as a composition antigen of tuberculosis vaccine exerts protective immune effects by inducing IL-17]

To explore the protective immune effect induced by mucosal delivery heparin-binding hemagglutinin (HBHA)-a candidate vaccine antigen of Mycobacterium tuberculosis. Female C57BL/6 mice were between 6 and 8 weeks of age before experimental use. Thirty mice received different immunization strategies and were randomly divided into the control group, the early secreting antigen target-6 (ESAT-6) intranasal immunization group, the HBHA intranasal immunization group, the BCG priming PBS control group, or BCG priming HBHA boost group, 6 mice in each group. In order to analyzed the immune effect, the concentrations of plasma Interleukin-17A (IL-17A) and other cytokines were measured by ELISA. Quantitative real-time PCR analyses were performed to detect the relative quantity (RQ) mRNA of IL-17A in the lung. The lung tissue sections were stained to detect the formation of the tertiary lymphoid structures. The chemokines contributed to formation of the tertiary lymphoid structures were also measured. Flow cytometry was used to detect the frequency of Th1 and Th17 cells in the system. Sixty mice in the BCG priming PBS control group and the BCG priming HBHA boost group were sacrificed at different time points after infection to count the lung bacterial burden. The concentrations of plasma IL-17A and relative quantity of lung IL-17A mRNA were highest in the BCG priming HBHA boost group [(14.76±4.73) pg/mL,RQ (12.27±6.71)], which was significantly higher than the control group [(5.57±2.95) pg/mL,RQ (1.30±0.97)] (t=4.213, P<0.001; t=5.984, P<0.001), and also significantly higher than the BCG priming PBS control group [(6.81±2.18) pg/mL,RQ (1.44±1.16)] (t=3.646 P=0.001; t=6.185 P<0.001). Compared with the BCG priming PBS control group (0.38±0.38)% the frequency of spleen Th17 cells were also significantly increased (t=-0.280, P=0.048) in the BCG-primary HBHA boost group (1.02±0.34)%. In addition, HBHA boosting could promote better formation of the tertiary lymphoid structures in the lung, and decrease the bacterial load on the early stage after BCG challenge. Collectively, mucosal delivery of HBHA can effectively enhance the protective effect after BCG vaccination, and it is a potential candidate vaccine component.

[Accuracy analysis of full-arch implant digital impressions when using a geometric feature]

Objective: To evaluate the effect of adding a geometric feature on the accuracy of digital impressions obtained by intraoral scanners for implant restoration of edentulous jaw quantitatively. Methods: A dentiform model of the maxilla of completely edentulous arch with 6 implant analogs+scan bodies (No. 1-6) was selected as the reference model. Without geometric feature, the dentiform model was scanned by dental model scanner and repeated for 5 times as true value group. Before and after adding the geometric feature, the same operator used intraoral scanner A (Trios 3) and B (Aoralscan 2) to scan the dentiform model with the same scanning path. Each type of intraoral scanner scanned 10 times and ".stl " datas were obtained. The results were imported into reverse engineering software (Geomagic Studio 2015). The linear distances of center point of upper plane between sacn body 1 to 6 was calculated, denoted as D12, D13, D14, D15 and D16. Trueness was the absolute value subtracted from the measured value of the intraoral scanner groups and true value; precision was the absolute value of pairwise subtraction of the measured values in the intraoral scanner groups.The smaller the value, the better the accuracy or precision.With or without the feature, all scan data were statistically analyzed, and the effect of adding geometric feature on the trueness and precision of the two intraoral scanners were evaluated. Results: As for intraoral scanner A, with the feature in place, significant differences were found in D14, D15, D16 for tureness(t=2.66, 2.75, 2.95, P<0.05); the trueness for D16 decreased from (101.9±47.1) μm to (49.6±30.3) μm. On the other hand, with features on the edentulous area, the precision was significantly increased in D15 and D16 (U=378.00, 672.00, P<0.05); the precision for D15 decreased from 40.8 (45.1) μm to 13.1 (17.0) μm. As for intraoral scanner B, the trueness of D12, D13 and D14 after adding geometric features was significantly better than before (t=3.02, 2.66, U=22.00, P<0.05). With feature on the edentulous area, the trueness for D13 decreased from (116.6±41.2) μm to (70.8±35.5) μm. There was no statistical significance in the trueness of D15 and D16 with or without geometric feature (P>0.05), however, the precision of D15 and D16 after adding geometric feature was significantly better than before (U=702.00, 489.00,P<0.05). The precision of D16 decreased from 112.5 (124.7) μm to 35.9 (85.8) μm. Conclusions: The use of geometric feature in edentulous space improves the trueness and precision of the different principle intraoral scanners tested.

Acupuncture Relieves Stress-Induced Depressive Behavior by Reducing Oxidative Stress and Neuroapoptosis in Rats

Oxidative stress is closely related to the occurrence of depression. Acupuncture has been proved to be an effective method for treating depression. In order to explore the mechanism of the antidepressant effect of acupuncture, this study performed acupuncture prevention on chronic unpredictable mild stress (CUMS) depression model rats, and observed the effect of acupuncture on hippocampal oxidative stress and Nrf2 signaling pathway. Male SD rats were randomly divided into control group, CUMS group, acupuncture group, and fluoxetine group (n = 10/group). Fluoxetine, a common antidepressant, was used as a positive control drug in this study. In the fluoxetine group, rats were given fluoxetine (2.1 mg/kg) intragastrically once a day for 28 days. The acupoints of Shangxing (GV23) and Fengfu (GV16) were applied in acupuncture group, once every other day for 14 times in total. Behavioral tests and biological detections were used to evaluate the effects of the interventions and the changes of factors related to oxidative stress, Nrf2 pathway, and neuronal apoptosis. The results showed that both acupuncture and fluoxetine could increase sugar preference rate in SPT and decrease immobility time in FST in depression model rats. It also significantly decreased oxidative stress products such as ROS and H2O2, and elevated the protein and mRNA expressions of Nrf2 and HO-1. From Nissl’s staining, there were more abundant nerve cells in two intervention groups compared with CUMS group. Plus, acupuncture down-regulated the expression levels of Bax and caspase-3 and up-regulated the expression of Bcl-2. Our findings indicate that acupuncture improved depression-like behaviors of CUMS rats. And CUMS-induced depression-like behaviors in rats were related to oxidative stress and neuronal apoptosis in hippocampus. Acupuncture showed antidepressant effects in reducing oxidative stress products via regulating the Nrf2/HO-1 signaling pathway so that prevented neuronal apoptosis.

Tai Chi for anxiety and depression symptoms in cancer, stroke, heart failure, and chronic obstructive pulmonary disease: A systematic review and meta-analysis

BACKGROUND

Many middle-aged and older adults have more than one chronic health condition. It is therefore important to explore the effectiveness of interventions for multiple chronic conditions. Tai Chi is widely used in China and other countries, and many studies have examined the effect of Tai Chi on anxiety and depression. However, there are no systematic reviews of the effect of Tai Chi on anxiety and depression in various chronic conditions. This systematic review and meta-analysis aimed to evaluate the effects of Tai Chi on anxiety and depression symptoms in four chronic conditions: cancer, stroke, heart failure (HF), and chronic obstructive pulmonary disease (COPD).

METHODS

We searched Chinese and English databases (Cochrane Library, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), Wanfang Database, and Sinomed) from inception to October 2020. Review Manager version 5.2 and Stata version 12.0 were used to perform a systematic review. The quality of the included studies was evaluated using the Cochrane risk of bias tool. The study was registered with the PROSPERO database (number CRD42020209594).

RESULTS

Of the 596 studies identified, we included 25 randomized controlled trials involving 1819 participants. Combined analysis of the four diseases showed statistically significant differences between the Tai Chi and control groups for anxiety symptoms (SMD -0.99, 95%CI: -1.5, -0.47; P < 0.01) and depressive symptoms (SMD 0.70, 95%CI: -1.01, -0.39; P < 0.01). Subgroup analyses showed statistically significant differences between the Tai Chi and control groups for depressive symptoms in stroke (SMD -0.43, 95%CI: -0.67, -0.18; P < 0.01) and HF (SMD -0.57, 95%CI: -0.8, -0.33; P < 0.01). However, no statistically significant differences were found for depressive symptoms in COPD or cancer. There were statistically significant differences between the Tai Chi and control groups for anxiety symptoms in stroke (SMD -0.60, 95%CI: -0.88, -0.32; P < 0.01) and cancer (SMD -0.69, 95%CI: -1.22, -0.17; P < 0.01), but not in COPD or HF. Subgroup, sensitivity, meta regression, and publication bias analyses showed high heterogeneity correlated with a single study and study quality. Sensitivity analysis showed that most meta-analysis results had good stability, but those for anxiety symptoms in COPD were unstable; therefore, careful interpretation is required.

CONCLUSION

Tai Chi has a positive effect on anxiety and depression, especially for patients with cancer, stroke, and HF. However, given the weak evidence, this approach is not a substitute for psychiatric treatment.

[Quantitative study of intraoral scanners' accuracy]

Objective: To establish a standard method to evaluate the scanning accuracy of intraoral scanner (IOS) and to investigate six IOS's scanning accuracy and the relationship between different scan span. Methods: Five simplified six abutments full arch model were fabricated by high accuracy (5 μm) milling machine with 7075 aluminum alloy. The machining accuracy, which was verified by a coordinate measuring machine with higher accuracy (0.7 μm), was considered as the reference accuracy. The model with the highest machining accuracy was considered as the test model in IOS's scanning accuracy test, and computer-aided design (CAD) data of the model was used as the reference data. Six IOS scanned the test model 10 times with the same scanning path, obtained 60 test data. CAD data and test data were input into Geomagic Studio 2014. The preparation part above the margin of the abutments of the data was isolated and divided into 4 segments of interest: single crown, three-unit bridge, five-unit bridge, and full arch. The test data were then best-fit aligned to CAD data or each other followed by deviation analysis. Scanning trueness and precision were then calculated. Results: The mid-value of scanning trueness and precision of six IOS in single crown, three-unit bridge, five-unit bridge and full arch were 13.3-29.6 μm and 7.6-20.7 μm, 15.4-30.9 μm and 8.7-26.5 μm, 17.0-66.1 μm and 11.3-44.2 μm, 24.0-107.9 μm and 24.6-150.1 μm respectively. Conclusions: Long-span scanning can affect the accuracy of IOS to a varying extent.

Therapeutic mechanism of Toujie Quwen granules in COVID-19 based on network pharmacology

Background

Chinese medicine Toujie Quwen granule (TJQW) has proven to be effective in the treatment of mild coronavirus disease 2019 (COVID-19) cases by relieving symptoms, slowing the progression of the disease, and boosting the recovery of patients. But the bioactive compounds and potential mechanisms of TJQW for COVID-19 prevention and treatment are unclear. This study aimed to explore the potential therapeutic mechanism of TJQW in coronavirus disease 2019 (COVID-19) based on an integrated network pharmacology approach.

Methods

TCMSP were used to search and screen the active ingredients in TJQW. The Swiss TargetPrediction was used to predict the potential targets of active ingredients. Genes co-expressed with ACE2 were considered potential therapeutic targets on COVID-19. Venn diagram was created to show correlative targets of TJQW against COVID-19. Cytoscape was used to construct a “drug-active ingredient-potential target” network, STRING were used to construct protein-protein interaction network, and cytoHubba performed network topology analysis. Enrichment of biological functions and signaling pathways of core targets was performed by using the clusterProfiler package in R software and ClueGO with CluePedia plugins in Cytoscape.

Results

A total of 156 active ingredients were obtained through oral bioavailability and drug-likeness screenings. Two hundred twenty-seven potential targets of TJQW were related to COVID-19. The top ten core targets are EGFR, CASP3, STAT3, ESR1, FPR2, F2, BCL2L1, BDKRB2, MPO, and ACE. Based on that, we obtained 19 key active ingredients: umbelliprenin, quercetin, kaempferol, luteolin, praeruptorin E, stigmasterol, and oroxylin A. And the enrichment analysis obtained multiple related gene ontology functions and signaling pathways. Lastly, we constructed a key network of “drug-component-target-biological process-signaling pathway”. Our findings suggested that TJQW treatment for COVID-19 was associated with elevation of immunity and suppression of inflammatory stress, including regulation of inflammatory response, viral process, neutrophil mediated immunity, PI3K-Akt signaling pathway, MAPK signaling pathway, Jak-STAT signaling pathway, Complement and coagulation cascades, and HIF-1 signaling pathway.

Conclusions

Our study uncovered the pharmacological mechanism underlying TJQW treatment for COVID-19. These results should benefit efforts for people around the world to gain more knowledge about Chinese medicine TJQW in the treatment of this vicious epidemic COVID-19, and help to address this pressing problem currently facing the world.

Astragaloside IV ameliorates intermittent hypoxia-induced inflammatory dysfunction by suppressing MAPK/NF-κB signalling pathways in Beas-2B cells

PURPOSE

Intermittent hypoxia is a characteristic pathological change in obstructive sleep apnoea (OSA) that can initiate oxidative stress reaction and pro-inflammatory cytokine release. The purpose of this study was to assess the effect and protective mechanism of Astragaloside IV (AS-IV) in intermittent hypoxia-induced human lung epithelial Beas-2B cells.

METHODS

Human lung epithelial Beas-2B cells were exposed to intermittent hypoxia or normoxia in the absence or presence of AS-IV. MTT assay was performed to determine the cell viability. The levels of reactive oxygen species (ROS), lactate dehydrogenase (LDH), malonaldehyde (MDA), and superoxide dismutase (SOD) were measured to evaluate oxidative stress. The levels of cytokines interleukin (IL)-8, IL-1β, and IL-6 were evaluated by enzyme-linked immunosorbent assay and real-time PCR. The expression of Toll-like receptor 4 (TLR4), mitogen-activated protein kinase (MAPK), and nuclear transcription factor-kappa B (NF-κB) signalling pathways was analysed by western blot.

RESULTS

The results showed that AS-IV significantly reduced the levels of ROS, LDH, MDA, IL-8, IL-1β, and IL-6, and increased the level of SOD in intermittent hypoxia-induced Beas-2B cells. It also suppressed the phosphorylation of MAPKs, including P38, c-Jun N-terminal kinase and extracellular signal-regulated kinase, and inhibited the activation of the NF-κB signalling pathway by reducing the phosphorylation of IκBα and p65.

CONCLUSIONS

AS-IV attenuates inflammation and oxidative stress by inhibiting TLR4-mediated MAPK/NF-κB signalling pathways in intermittent hypoxia-induced Beas-2B cells.

Acute Toxicity and Hazardous Concentrations of Zinc to Native Freshwater Organisms Under Different pH Values in China

Zinc bioavailability to aquatic organisms varies greatly under different pH values. In the present study, five native species in China and four common international test species were selected to investigate the influence of changing pH on acute zinc toxicity. The results showed that the higher trophic levels exhibited increasing sensitivity to zinc as pH decreased. However, when the pH value was between 8 and 11, the acute toxicity of zinc was relatively constant. In addition, by using a species-sensitivity distribution (SSD) method, the short-term hazardous concentrations of zinc at different pH values (based on the 5th percentiles of the pH-specific SSDs) were determined to be 17.26 µg/L (pH 4), 48.31 µg/L (pH 5), 80.34 µg/L (pH 6) and 230.6 µg/L (pH 7), respectively. The present study provides useful information for deriving water quality criteria and assessing the risks of metals in the near future.

[Depletion of GP73 inhibits invasion and metastasis of hepatocellular carcinoma cells]

Objective: To explore the in vitro and in vivo effect of GP73 on the proliferation, invasion and metastasis in hepatocellular carcinoma. Methods: GP73 gene was knocked out using CRISPR/Cas9 gene editing system in H22 and HepG2 cells, and stable knock out strains were constructed. The knockout efficiency was measured by western blot. Colony formation assay was used to detect the effect of GP73 on long-term survival ability. Cells were then highly synchronized in G(1) phase upon treatment with cell synchronization reagents (mimosine), and the percentage of cells in G(2)/M phase at different time points was detected by flow cytometry. The invasive and metastasis abilities of hepatocellular carcinoma cells were detected by Transwell™ assay. Furthermore, the tumor formation abilities in vivo were examined using subcutaneous xenograft models. Results: The stable knock out strains of GP73 in H22 and HepG2 cells were successfully established via puromycin selection. The number of colonies of GP73 knock out groups in HepG2 and H22 cells 10 days after transfection were 400±70 and 248±60, respectively. They were significantly lower than those in the control groups (980±40 and 1 100±50, respectively; P<0.01). In addition, GP73 knockout slowed down the cell cycle progression. Moreover, the cell numbers that had migrated to the underside of the filters were 312±50 and 305±49 in the GP73 knockout groups of HepG2 and H22 cells, respectively, significantly lower than 1 540±87 and 1 270±86 in the controls (P<0.01). For transwell invasion assay, the cell number that had invaded into the underside of the filters were 230±47 and 238±54 in the GP73 knockout groups of HepG2 and H22 cells, respectively, significantly lower than 648±74 and 596±63 in the controls(P<0.01). Furthermore, the tumor volume of GP73 knockout group was (70±170) mm(3,) significantly smaller than (1 200±110)mm(3) of the control guoup (P<0.01). Conclusions: GP73 knockout decreases the proliferation, invasive and migratory abilities of HepG2 and H22 cells in vitro and in vivo. GP73 may contribute to tumorigenesis of hepatocellular carcinoma.

Tuberculous peritonitis and pleurisy accompanied by pulmonary cryptococcosis: A case report

Although the infectious diseases tuberculosis (TB) and cryptococcosis both cause formation of single or multiple nodules in immunodeficient hosts, cases of co-infection of these diseases are rarely seen. We report a patient who was co-infected with TB and cryptococcosis. A male patient with no clinical evidence of immunodeficiency presented with a 3-week history of abdominal distension accompanied by oedema of recurring lower extremities. The patient was diagnosed with tuberculous peritonitis and tuberculous pleurisy by an abdominal puncture biopsy. Several months after being treated for TB, the patient was diagnosed with Cryptococcus infection and received antifungal treatment. Computed tomographic and magnetic resonance imaging findings suggested that treatment was effective. This case illustrates the challenges encountered during assessment of neoplasms associated with TB and cryptococcosis. Differential diagnosis requires an abdominal puncture biopsy. Diagnosis of Cryptococcus infection also requires a positive cryptococcal culture and positive India ink staining analysis. Notably, our patient also showed no obvious symptoms of cryptococcosis after receiving anti-TB treatment. Accordingly, in this report, we discuss the possible pathogenic mechanisms that underlie the coincidence of both types of inflammatory lesions. We emphasize the need for a greater awareness of atypical presentations of TB accompanied by Cryptococcus infection.

Local structure, nucleation sites and crystallization behavior and their effects on magnetic properties of Fe81Si x B10P8-xCu1 (x = 0~8)

In this work, an attempt has been made to reveal critical factors dominating the crystallization and soft magnetic properties of Fe₈₁Si _x B₁₀P_8-xCu₁ (x = 0, 2, 4, 6 and 8) alloys. Both melt spun and annealed alloys are characterized by differential scanning calorimetry, X-ray diffractometry, Mössbauer spectroscopy, transmission electron microscopy, positron annihilation lifetime spectroscopy and magnetometry. The changes in magnetic interaction between Fe atoms and chemical homogeneity can well explain the variation of magnetic properties of Fe₈₁Si _x B₁₀P_8-xCu₁ amorphous alloys. The density of nucleation sites in the amorphous precursors decreases in the substitution of P by Si. Meanwhile, the precipitated nanograins gradually coarsen, but the inhibiting effect of P on grain growth diminishes causing the increase of the crystallinity. Moreover, various site occupancies of Si are observed in the nanocrystallites and the Si occupancy in bcc Fe decreases the average magnetic moment of nanograins. Without sacrificing amorphous forming ability, we can obtain FeSiBPCu nanocrystalline alloy with excellent soft magnetic properties by optimizing the content of Si and P in the amorphous precursors.

Anomalous optical forces on the anisotropic Rayleigh particles

We investigate the optical forces on the radially anisotropic spheres from an incident plane wave based on our generalized full-wave scattering theory and the Maxwell stress tensor integration techniques. We demonstrate that the optical force on the Rayleigh sphere with radial anisotropy does not always obey the well-known Rayleigh's law F~k04a(6) (where k(0) is the wave number and a is the radius of the sphere), but could be anomalous with the laws such as F~k00a(2), F~k0-2a(0), and F~k08a(10) under certain conditions. Therefore, the optical force on the anisotropic Rayleigh spheres is enhanced at the electric dipole resonance, and may be further increased by tuning the anisotropic parameters. On the contrary, the optical forces on the anisotropic spheres can be largely reduced for anisotropic spheres with electromagnetic transparency.

Thermal response of a dental tissue induced by femtosecond laser pulses

This paper reports a theoretical and experimental study for thermal transport in a thin slice of human tooth induced by a 120 fs, 800 nm pulse laser at a repetition rate of 1 kHz. The surface reflectivity of enamel and the convection heat transfer coefficient were determined using an inverse heat transfer analysis. Instead of a fully three-dimensional modeling, two simplified two-dimensional (2D) planar and axisymmetric heat conduction models were proposed to simulate the temperature fields. The temperature responses obtained from the 2D planar and axisymmetric model agree well with the experimental measurements. On the other hand, the one-dimensional (1D) result significantly differs from the 2D axisymmetric one, suggesting that care should be taken when a 1D thermal model is considered for estimating temperature response.

Nonequilibrium phase change in gold films induced by ultrafast laser heating

Ultrafast laser-induced melting in a gold thin film is simulated by an integrated continuum-atomistic method with the extended Drude model for dynamic optical properties. The local order parameter of atoms is used to identify solid and liquid regions. It is shown that the film is superheated in the early nonequilibrium stage and the melted region grows very quickly with a very high rate of melting up to ∼13,300 m/s. It is also found that the continuum approach could significantly underestimate the ultrafast phase-change response, and temperature-dependent optical properties should be considered in atomic-level modeling for ultrafast laser heating.

Low energy laser light (632.8 nm) suppresses amyloid-β peptide-induced oxidative and inflammatory responses in astrocytes

Oxidative stress and inflammation are important processes in the progression of Alzheimer's disease (AD). Recent studies have implicated the role of amyloid β-peptides (Aβ) in mediating these processes. In astrocytes, oligomeric Aβ induces the assembly of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complexes resulting in its activation to produce anionic superoxide. Aβ also promotes production of pro-inflammatory factors in astrocytes. Since low energy laser has previously been reported to attenuate oxidative stress and inflammation in biological systems, the objective of this study was to examine whether this type of laser light was able to abrogate the oxidative and inflammatory responses induced by Aβ. Primary rat astrocytes were exposed to Helium-Neon laser (λ=632.8 nm), followed by the treatment with oligomeric Aβ. Primary rat astrocytes were used to measure Aβ-induced production of superoxide anions using fluorescence microscopy of dihydroethidium (DHE), assembly of NADPH oxidase subunits by the colocalization between the cytosolic p47(phox) subunit and the membrane gp91(phox) subunit using fluorescent confocal microscopy, phosphorylation of cytosolic phospholipase A(2) cPLA(2) and expressions of pro-inflammatory factors including interleukin-1β (IL-1β) and inducible nitric-oxide synthase (iNOS) using Western blot Analysis. Our data showed that laser light at 632.8 nm suppressed Aβ-induced superoxide production, colocalization between NADPH oxidase gp91(phox) and p47(phox) subunits, phosphorylation of cPLA(2,) and the expressions of IL-1β and iNOS in primary astrocytes. We demonstrated for the first time that 632.8 nm laser was capable of suppressing cellular pathways of oxidative stress and inflammatory responses critical in the pathogenesis in AD. This study should prove to provide the groundwork for further investigations for the potential use of laser therapy as a treatment for AD.

Simulation of laser-induced thermotherapy using a dual-reciprocity boundary element model with dynamic tissue properties

This paper presents a nonlinear dual-reciprocity boundary element method (DRBEM) for bioheat transfer in laser-induced thermotherapy. The nonlinearity stems from the dynamic changes of tissue thermophysical and optical properties and the blood perfusion rate during laser heating. The proposed DRBEM is coupled with a modified Monte Carlo method and the Arrhenius rate equation to investigate laser light propagation, bioheat transfer, and irreversible thermal damage in tumors. The computer code is justified by comparing the DRBEM results with the finite-difference results. The photothermal processes in interstitial laser thermotherapy with single or double laser fiber scattering applicators are chosen as the demonstrative examples. The dynamic nature, together with the unique advantages of "boundary-only" and excellent adaptability to complex anatomical geometries that the DRBEM method offers, makes the present nonlinear DRBEM a powerful tool for analysis and optimization of the parameters in laser surgical procedure.

Biostabilization assessment of MSW co-disposed with MSWI fly ash in anaerobic bioreactors

Municipal solid waste incinerator (MSWI) fly ash has been examined for possible use as landfill interim cover. For this aim, three anaerobic bioreactors, 1.2m high and 0.2m in diameter, were used to assess the co-digestion or co-disposal performance of MSW and MSWI fly ash. Two bioreactors contained ratios of 10 and 20 g fly ash per liter of MSW (or 0.2 and 0.4 g g(-1) VS, that is, 0.2 and 0.4 g fly ash per gram volatile solids (VS) of MSW). The remaining bioreactor was used as control, without fly ash addition. The results showed that gas production rate was enhanced by the appropriate addition of MSWI fly ash, with a rate of approximately 6.5l day(-1)kg(-1)VS at peak production in the ash-added bioreactors, compared to approximately 4l day(-1)kg(-1)VS in control. Conductivity, alkali metals and VS in leachate were higher in the fly ash-added bioreactors compared to control. The results show that MSW decomposition was maintained throughout at near-neutral pH and might be improved by release of alkali and trace metals from fly ash. Heavy metals exerted no inhibitory effect on MSW digestion in all three bioreactors. These phenomena indicate that proper amounts of MSWI fly ash, co-disposed or co-digested with MSW, could facilitate bacterial activity, digestion efficiency and gas production rates.

Solubility of heavy metals added to MSW

This paper aims to investigate the six heavy metal levels (Cd, Cr, Cu, Pb, Ni and Zn) in municipal solid waste (MSW) at different pHs. It intends to provide the baseline information of metals solubility in MSW co-disposed or co-digested with MSW incinerator ashes in landfill or anaerobic bioreactors or heavy metals contaminated in anaerobic digesters. One milliliter (equal to 1mg) of each metal was added to the 100ml MSW and the batch reactor test was carried out. The results showed that higher HNO3 and NaOH were consumed at extreme pH of 1 and 13 compared to those from pH 2 to 11 due to the comparably higher buffer capacity. Pb was found to have the least soluble level, highest metal adsorption (%) and highest partitioning Kd (lg(-1)) between pH 3 and 12. In contrast, Ni showed the highest soluble level, lowest metal adsorption (%) and lowest Kd (lg(-1)) between pH 4 and 12. Except Ni and Cr, other four metals seemed to show the amphibious properties as comparative higher solubility was found in the acidic and basic conditions.

Theoretical analysis of thermal damage in biological tissues caused by laser irradiation

A bioheat transfer approach is proposed to study thermal damage in biological tissues caused by laser radiation. The laser light propagation in the tissue is first solved by using a robust seven-flux model in cylindrical coordinate system. The resulting spatial distribution of the absorbed laser energy is incorporated into the bioheat transfer equation for solving temperature response. Thermal damage to the tissue is assessed by the extent of denatured protein using a rate process equation. It is found that for the tissue studied, a significant protein denaturation process would take place when temperature exceeds about 53 degrees C. The effects of laser power, exposure time and beam size as well as the tissue absorption and scattering coefficients on the thermal damage process are examined and discussed. The laser conditions that cause irreversible damage to the tissue are also identified.

Multi-resolution image fusion technique and its application to forensic science

Image fusion is a process of combining two or more images into an image. It can extract features from source images, and provide more information than one image can. Multi-resolution analysis plays an important role in image processing, it provides a technique to decompose an image and extract information from coarse to fine scales. In some practical forensic examinations (such as the cartridge image check), we cannot obtain all information from just one image; on the contrary, we need information from images with difference light sources (or light ways). In this paper, we apply an image fusion method based on multi-resolution analysis to forensic science. Synthetic and real images (such as images from closed-up photography and flash photography) are used to show the capability of the multi-resolution image fusion technique.

Genetic diversity in the northernmost Oryza rufipogon populations estimated by SSR markers

To estimate genetic diversity of the residual northern populations of Oryza rufipogon, a total of 232 individuals from six populations were analyzed using microsatellites (SSRs). The O. rufipogon populations with different status included three from Dongxiang (Jiangxi Province) and three from Chaling (Hunan Province) in China. The 23 rice SSR primer pairs selected from the RiceGenes Database detected a total of 115 alleles, indicating that all the SSR loci were polymorphic in this study. The total gene diversity was 0.919 in the six O. rufipogon populations, and the Donxiang populations showed higher diversity than the Chaling populations. More significant genetic differentiation and less gene flow were found among the Dongxiang populations than those from Chaling. The two putative introgressed populations showed relatively high genetic variation. One in situ conserved population from Dongxiang had the lowest level of genetic diversity. The re-introduced population from Chaling restored about 90% of the genetic variation, compared with the original source population. It is concluded from these results that a relatively high level of genetic variation resided in the northern O. rufipogon populations and continued efforts of conservation of these populations are needed; and that the conservation of some Chaling and Dongxiang populations has been effective in preventing gene flow from cultivated rice. Introgression of cultivated rice demonstrated significant impacts on genetic variability of the O. rufipogon populations, and should be carefully considered in conserving this wild rice. This study also suggested that re-introduction to its original habitats is an effective approach to restore O. rufipogon populations.

Ex vivo gene therapy in autologous bone marrow stromal stem cells for tissue-engineered maxillofacial bone regeneration

This study examines the clinical relevance of tissue engineering integrating gene therapy and polymer science to bone regeneration. Bilateral maxillary defects (3 x 1.2 cm(2)) in 20 miniature swine were bridged with a bioresorbable internal splint. Constructs were created using ex vivo adenovirus bone morphogenetic protein (BMP)-2-mediated gene transfer to the expanded bone marrow mesenchymal stem cells (MSCs) 7 days before implantation. Controls were performed using adenovirus beta-galactosidase. The BMP-2 cell/construct displayed white solid bone formation after 3 months. Meanwhile, the hematoxylin and eosin and Von Kossa stains demonstrated exhibited mature woven bone with good mineralization. Additionally, three-dimensional computer tomography imaging revealed a nearly complete infraorbital rim repair. Quantitative analysis demonstrated a significant difference (P<0.001) in bone formation. Finally, biomechanical testing revealed no statistically significant difference in the maximal compressive strength of new bone formed by BMP-2 cell constructs and the normal maxilla. The data evidenced de novo bone formation capable of sustaining axial compressive loads. The measurement results showed that ex vivo replication defective adenovirus-mediated human BMP-2 gene transfer to MSCs enhances autologous bone formation in the repair of maxillary defects.

Visualizing caveolin-1 and HDL in cholesterol-loaded aortic endothelial cells

Caveolae are vesicular invaginations of the plasma membranes that regulate signal transduction and transcytosis, as well as cellular cholesterol homeostasis. Our previous studies indicated that the removal of cholesterol from aortic endothelial cells and smooth muscle cells in the presence of HDL is associated with plasmalemmal invaginations and plasmalemmal vesicles. The goal of the present study was to investigate the location and distribution of caveolin-1, the main structural protein component of caveolae, in cholesterol-loaded aortic endothelial cells after HDL incubation. Confocal microscopic analysis demonstrated that the caveolin-1 appeared to colocalize with HDL-fluorescein 1,1'-dioctadecyl 3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) conjugates on the cell surface. No free HDL-DiI conjugates were revealed in the cytoplasm. Immunoelectron microscopy further demonstrated that caveolin-1 gold (15 nm) conjugates colocalized with HDL gold (10 nm) conjugates in the plasmalemmal invaginations. These morphological results indicated that caveolae are the major membrane domains facilitating the transport of excess cholesterol to HDL on the cell surface of aortic endothelial cells.

Detection of DNA strand breaks, DNA-protein crosslinks, and telomerase activity in nickel-transformed BALB/c-3T3 cells

Although nickel compounds are known carcinogens, the underlying carcinogenic mechanisms are not fully understood. The objective of this research was to determine if the genotoxic lesions of DNA strand breaks and DNA-protein crosslinks are present in nickel-transformed BALB/c-3T3 cells, and to further elucidate the potential carcinogenesis of insoluble and soluble nickel compounds through telomerase activity in nickel-transformed BALB/c-3T3 cell lines. DNA strand breaks, DNA-protein crosslinks and telomerase activity were investigated by single cell gel electrophoresis (comet assay), (125)I-postlabelling techniques, and the TRAP-silver staining assay, respectively. Results showed that both DNA strand breaks and DNA-protein crosslinks were present in nickel-transformed BALB/c-3T3 cells. However, the highest levels of DNA strand breaks and DNA-protein crosslinks were found in insoluble crystalline NiS-transformed cells and high levels of DNA strand breaks and DNA-protein crosslinks were also found in the transformed cells induced by two water-soluble NiCl(2) and NiSO(4) at moderate concentrations of cytotoxicity. These data suggest that these two genetic endpoints are useful biomarkers and are associated with cell transformation and carcinogensis of insoluble and soluble nickel compounds. Also, we found that the crystalline NiS- and NiCl(2)-transformed cells possessed a high telomerase activity. A weak telomerase was found in NiSO(4)-transformed cells. The results seem to indicate that in addition to crystalline NiS, some water-soluble nickel compounds such as NiCl(2) are also highly carcinogenic. These results may partly explain the cell transformation and relative carcinogenic potency of insoluble crystalline NiS, soluble NiCl(2), and NiSO(4).

Expression of matrix metalloproteinases 2 and 9 and tissue inhibitors of metalloproteinase 1 and 2 in inflammation-induced corneal neovascularization

PURPOSE

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) have been linked to the angiogenic process in general. In order to understand the potential roles of MMP-2, MMP-9 and TIMPs in the corneal neovascularization process, we examined the expression and activities of MMP-2, MMP-9 and TIMPs during the course of cauterization-induced corneal neovascularization in a rat model.

METHODS

Neovascularization of rat corneas was induced by silver nitrate cauterization. The expression of MMP-2, MMP-9, TIMP-1 and TIMP-2 was examined by immunohistochemistry and RT-PCR. The protein activities of MMPs and TIMPs were compared in pre- and postcauterization corneas by gelatin zymography and reverse zymography, respectively.

RESULTS

MMP-2, TIMP-1 and TIMP-2 immunoreactivities were expressed in normal corneas, predominantly in the corneal epithelium. After injury, immunoreactivities of both MMPs and TIMPs were increased, notably in the healing corneal epithelium, infiltrating inflammatory cells, stromal fibroblasts and ingrowing vascular endothelial cells. The increase in gross MMP-2 enzymatic activity paralleled the maximal vascular ingrowth on day 4, while the gross MMP-9 enzymatic activity rose immediately on day 1, then decreased steadily, which paralleled the magnitude of inflammatory cell infiltration. The immunoreactivity of MMPs/TIMPs decreased significantly 2 weeks after cauterization. On day 35, MMP-2, TIMP-1 and TIMP-2 staining was seen only in corneal epithelium and vascular endothelial cells. Both the RT-PCR and reverse zymography results revealed a more constant expression of TIMP-2, while the TIMP-1 expression appeared to be more inducible.

CONCLUSION

MMPs as well as TIMPs were upregulated in cauterization-induced corneal neovascularization, suggesting that both may participate in extracellular matrix remodeling in the corneal wound healing, inflammation and neovascularization processes.

Cytochrome p450 epoxygenase metabolism of arachidonic acid inhibits apoptosis

The ubiquitous cytochrome P450 hemoproteins play important functional roles in the metabolism and detoxification of foreign chemicals. However, other than established roles in cholesterol catabolism and steroid hormone biosynthesis, their cellular and/or organ physiological functions remain to be fully characterized. Here we show that the cytochrome P450 epoxygenase arachidonic acid metabolite 14,15-epoxyeicosatrienoic acid (14,15-EET) inhibits apoptosis induced by serum withdrawal, H(2)O(2), etoposide, or excess free arachidonic acid (AA), as determined by DNA laddering, Hoechst staining, and fluorescein isothiocyanate-labeled annexin V binding. In the stable transfectants (BM3 cells) expressing a mutant bacterial P450 AA epoxygenase, F87V BM3, which was genetically engineered to metabolize arachidonic acid only to 14,15-EET, AA did not induce apoptosis and protected against agonist-induced apoptosis. Ceramide assays demonstrated increased AA-induced ceramide production within 1 h and elevated ceramide levels for up to 48 h, the longest time tested, in empty-vector-transfected cells (Vector cells) but not in BM3 cells. Inhibition of cytochrome P450 activity by 17-octadecynoic acid restored AA-induced ceramide production in BM3 cells. Exogenous C2-ceramide markedly increased apoptosis in quiescent Vector cells as well as BM3 cells, and apoptosis was prevented by pretreatment of Vector cells with exogenous 14,15-EET and by pretreatment of BM3 cells with AA. The ceramide synthase inhibitor fumonisin B1 did not affect AA-induced ceramide production and apoptosis; in contrast, these effects of AA were blocked by the neutral sphingomyelinase inhibitor scyphostatin. The pan-caspase inhibitor Z-VAD-fmk had no effect on AA-induced ceramide generation but abolished AA-induced apoptosis. The antiapoptotic effects of 14,15-EET were blocked by two mechanistically and structurally distinct phosphatidylinositol-3 (PI-3) kinase inhibitors, wortmannin and LY294002, but not by the specific mitogen-activated protein kinase kinase inhibitor PD98059. Immunoprecipitation followed by an in vitro kinase assay revealed activation of Akt kinase within 10 min after 14,15-EET addition, which was completely abolished by either wortmannin or LY294002 pretreatment. In summary, the present studies demonstrated that 14,15-EET inhibits apoptosis by activation of a PI-3 kinase-Akt signaling pathway. Furthermore, cytochrome P450 epoxygenase promotes cell survival both by production of 14,15-EET and by metabolism of unesterified AA, thereby preventing activation of the neutral sphingomyelinase pathway and proapoptotic ceramide formation.

[Experimental studies of genistein on the proliferation and apoptosis of human prolactinoma cells cultured in vitro]

AIM

To study the influence of genistein (GST) on the proliferation and apoptosis of cultured human prolactinoma cells.

METHODS

MTT method and 3H-TdR incorporation and cell cycle analysis were used to examine the changes of proliferation and DNA synthesis of human prolactinoma cells under influence of GST and beta-estradiol (E2). Tdt-mediated dUTP nick end labeling (TUNEL) were employed to observe the effect of GST and E2 on the apoptosis of human prolactinoma cells.

RESULTS

In a dose dependent manner, GST of different concentration could significantly inhibit the proliferation of human prolactinoma cells cultured in vitro. GST(10(-5) mol/L) could increase the proportion of cells in G1 phase from 55.3% up to 90.3%. E2 of different concentration could dose-dependently increase the proliferation of human prolactinoma cells. E (10(-5) mol/L) could increase the proportion of cells in G2 phase from 15.6% up to 41.8%. However, a lower suppressive proliferation of cultured human prolactinoma cells was observed with GST and E2 together. GST, not E2, could significantly induce the apoptosis of human prolactinoma cells cultured in vitro.

CONCLUSION

GST inhibits the proliferation, DNA synthesis and cell cycle of cultured human pituitary cells, and induces its apoptosis. E2 decreases partly the effect of GST on the suppression of proliferation, not apoptotic induction, of human prolactinoma cells cultured in vitro.

New frontiers in diagnostic imaging in concussive head injury

Concussed athletes may have documented incapacitating postconcussive symptoms, neuropsychological deficits, and consequent important changes in their lives and sport, yet the majority of neuroimaging attempts reveal few findings to account for these signs and symptoms. In this paper, we explore new techniques in the neuroimaging of concussion including diffusion-weighted magnetic resonance imaging and functional brain imaging technology.

Angiotensin IV induces tyrosine phosphorylation of focal adhesion kinase and paxillin in proximal tubule cells

Angiotensin IV (ANG IV), the COOH-terminal hexapeptide fragment of angiotensin II (ANG II), binds to specific sites in the kidney, distinct from type 1 (AT(1)) and type 2 (AT(2)) receptors and designated type 4 (AT(4)) receptors. We determined signaling pathways for ANG IV in a proximal tubular cell line, LLC-PK(1)/Cl(4). In these cells, we found no specific binding of [(125)I]-ANG II. In contrast, ANG IV dose dependently competed for [(125)I]-labeled ANG IV binding, with no displacement by either ANG II, the AT(1) receptor antagonist losartan, or the AT(2) antagonist PD-123319. Saturation binding indicated the presence of AT(4) receptors of high affinity [dissociation constant (K(d)) = 1.4 nM]. ANG IV did not affect cAMP or cGMP production and did not increase cytosolic calcium concentration in these cells. In contrast, immunoprecipitation and immunoblotting studies revealed that ANG IV caused dose-dependent tyrosine phosphorylation of p125-focal adhesion kinase (p125-FAK) and p68-paxillin within 2 min, with maximal stimulation at 30 min. ANG IV-stimulated tyrosine phosphorylation of p125-FAK and paxillin was not affected by pretreatment with either losartan or PD-123319, and ANG II (10(-7) M) did not induce protein tyrosine phosphorylation. Our results indicate that LLC-PK(1)/Cl(4) cells express ANG IV receptors, which we demonstrate for the first time are linked to tyrosine phosphorylation of focal adhesion-associated proteins. This suggests that ANG IV, a product of ANG II metabolism, may regulate function of the focal adhesion complex in proximal tubule cells.

Margulis' theory on division of labour in cells revisited

Division of labour is a marked feature of multicellular organisms. Margulis proposed that the ancestors of metazoans had only one microtubule organizing center (MTOC), so they could not move and divide simultaneously. Selection for simultaneous movement and cell division had driven the division of labour between cells. However, no evidence or explanation for this assumption was provided. Why could the unicellular ancestors not have multiple MTOCs? The gain and loss of three possible strategies are discussed. It was found that the advantage of one or two MTOC per cell is environment-dependent. Unicellular organisms with only one MTOC per cell are favored only in resource-limited environments without strong predatory pressure. If division of labour occurring in a bicellular organism just makes simultaneous movement and cell division possible, the possibility of its fixation by natural selection is very low because a somatic cell performing the function of an MTOC is obviously wasting resources. Evolutionary biologists should search for other selective forces for division of labour in cells.

Beneficial effects of astringinin, a resveratrol analogue, on the ischemia and reperfusion damage in rat heart

Oxidative stress plays an important role in the pathogenesis of myocardial ischemia and infarction. Antioxidants might then be beneficial in the prevention of these diseases. Astringinin (3,3',4',5-tetrahydroxystilbene), a resveratrol (3,4',5-trihydroxystilbene) analogue with considerably higher antioxidative activity and free radical scavenging capacity, was introduced to examine its cardioprotective effects in ischemia or ischemia-reperfusion (I/R) rats. In the present study, the left main coronary artery was occluded by the following procedures: (i) 30 min occlusion, (ii) 5 min occlusion followed by 30 min reperfusion, and (iii) 4 h occlusion. Animals were infused with and without astringinin before coronary artery occlusion. Mortality, and the severity of ischemia- and I/R-induced arrhythmias were compared. Pretreatment of astringinin dramatically reduced the incidence and duration of ventricular tachycardia (VT) and ventricular fibrillation (VF) during either ischemia or I/R period. Astringinin at 2.5 x 10(-5) and 2.5 x 10(-4) g/kg completely prevented the mortality of animals during ischemia or I/R. During the same period, astringinin pretreatment also increased nitric oxide (NO) and decreased lactate dehydrogenase (LDH) levels in the carotid blood. In animals subjected to 4 h coronary occlusion, the cardiac infarct size (expressed as a percentage of occluded zone) was reduced from 44.4 + or - 4.1% to 19.1 + or - 2.4% by astringinin (2.5 x 10(-4) g/kg). We conclude that, astringinin is a potent antiarrhythmic agent with cardioprotective activity in ischemic and ischemic-reperfused rat heart. The beneficial effects of astringinin in the ischemic and ischemic-reperfused hearts may be correlated with its antioxidant activity and upregulation of NO production.

[Effect of interleukin 2 on the expression of estrogen receptors in the anterior pituitary of rats]

Using primary serum-free cell culture combined with immunocytochemistry and semi-quantified RT-PCR methods, we observe the modulation of estrogen receptor alpha (ERalpha) and beta (ERbeta) by interleukin-2 (IL-2) in rat anterior pituitary. The results show that IL-2 up-regulates the level of ERalpha protein and the expression of ERalpha mRNA, but down-regulates those of ERbeta. The density per cell of ERalpha-immunoreactive (ir) cells increases from 48.740 4.567 to 81.188+/-6.619, whereas that of ERbeta -ir cells decreases from 102.560+/-6.250 to 72.718+/-7.623 after rhIL-2 (10 microgram/L) incubation for 48 h. In parallel with these changes, the ratio of ERalpha/ beta -actin mRNA increases from 0.1511 to 0.4334, and ERbeta /beta -actin mRNA declines from 0.3822 to 0.1528. It is likely that IL-2 has direct regulatory effect on ER in anterior pituitary.

The USF proteins regulate transcription of the follicle-stimulating hormone receptor but are insufficient for cell-specific expression

Expression of the FSH receptor (FSHR) is limited to granulosa cells of the ovary and Sertoli cells of the testis. Previous studies showed that an E box in the proximal promoter of the FSHR gene is required for transcription and that the predominant E box binding proteins are the ubiquitous transcription factors, upstream stimulatory factor 1 (USF1) and USF2. Through cotransfection analysis, we have shown that both wild-type and dominant negative forms of the USF proteins regulate the rat FSHR promoter and that transcriptional activation of FSHR required several domains within the amino-terminal portion of the USF proteins. Analysis of the FSHR promoter region using in vivo genomic footprinting indicated that the E box is occupied by proteins in Sertoli cells but not in cells that fail to express the receptor, despite the presence of the USF proteins. To help delineate the regions of the rat FSHR gene required for correct spatial and temporal expression, transgenic mice harboring two constructs containing variable amounts of 5'-flanking sequence (5,000 bp and 100 bp) were generated. Examination of 16 different transgenic lines revealed varied transgene expression profiles with multiple lines having different amounts of ectopic expression and two lines failing to express the transgene. In addition, little or no expression was observed in Sertoli cells. These studies indicate that additional regulatory sequences outside the region from -5,000 to +123 bp are needed for proper expression in Sertoli cells.

Effects of oncogenic mutations in Smoothened and Patched can be reversed by cyclopamine

Basal cell carcinoma, medulloblastoma, rhabdomyosarcoma and other human tumours are associated with mutations that activate the proto-oncogene Smoothened (SMO) or that inactivate the tumour suppressor Patched (PTCH). Smoothened and Patched mediate the cellular response to the Hedgehog (Hh) secreted protein signal, and oncogenic mutations affecting these proteins cause excess activity of the Hh response pathway. Here we show that the plant-derived teratogen cyclopamine, which inhibits the Hh response, is a potential 'mechanism-based' therapeutic agent for treatment of these tumours. We show that cyclopamine or synthetic derivatives with improved potency block activation of the Hh response pathway and abnormal cell growth associated with both types of oncogenic mutation. Our results also indicate that cyclopamine may act by influencing the balance between active and inactive forms of Smoothened.

Cardioprotective effect of resveratrol, a natural antioxidant derived from grapes

BACKGROUND

The major objective of the present study was to examine the cardioprotective effect of resveratrol, an antioxidant presents in red wines, in the rat after ischemia and ischemia-reperfusion (I-R).

METHODS

The left main coronary artery was occluded for 30 or 5 min followed by a 30-min reperfusion in anesthetized rats. Animals were preinfused with and without resveratrol before occlusion and the severity of ischemia- and I-R-induced arrhythmias and mortality were compared.

RESULTS

Resveratrol pretreatment had no effect on ischemia-induced arrhythmias nor on mortality. In contrast, a dramatic protective effects were observed against I-R-induced arrhythmias and mortality. Resveratrol pretreatment both reduced the incidence and duration of ventricular tachycardia (VT) and ventricular fibrillation (VF). During the same period, resveratrol pretreatment also increased nitric oxide (NO) and decreased lactate dehydrogenase levels in the carotid blood.

CONCLUSIONS

Resveratrol is a potent antiarrhythmic agent with cardioprotective properties in I-R rats. The cardioprotective effects of resveratrol in the I-R rats may be correlated with its antioxidant activity and upregulation of NO production.

Reconstruction of damaged corneas by transplantation of autologous limbal epithelial cells

BACKGROUND

Stevens-Johnson syndrome, ocular pemphigoid, and thermal or chemical burns can cause scarring and opacification of the cornea and loss of vision. Transplantation of epithelial cells from the limbus of the contralateral cornea can restore useful vision. However, this procedure requires a large limbal graft from the healthy eye and is not possible in patients who have bilateral lesions.

METHODS

We took specimens of limbal epithelial cells from the healthy contralateral eyes of six patients with severe unilateral corneal disease. The epithelial cells were cultured and expanded on amniotic membrane. The amniotic membrane, together with the sheet of limbal epithelial cells, was transplanted to the denuded corneal surface of the damaged eye after superficial keratectomy to remove fibrovascular ingrowth. The mean (+/-SD) follow-up period was 15+/-2 months.

RESULTS

Complete reepithelialization of the corneal surface occurred within two to four days of transplantation in all six eyes receiving transplants. By one month, the ocular surface was covered with corneal epithelium, and the clarity of the cornea was improved. In five of the six eyes receiving transplants (83 percent), the mean visual acuity improved from 20/112 to 20/45. In one patient with a chemical burn who had total opacification of the cornea, the acuity improved from the ability to count fingers at 40 cm to 20/200. No patient had recurrent neovascularization or inflammation in the transplanted area during the follow-up period.

CONCLUSIONS

Transplantation of autologous limbal epithelial cells cultured on amniotic membrane is a simple and effective method of reconstructing the corneal surface and restoring useful vision in patients with unilateral deficiency of limbal epithelial cells.

Expression of bone sialoprotein in mineralized tissues of tooth and bone and in buccal-pouch carcinomas of Syrian golden hamsters

The expression of bone sialoprotein (BSP) is normally restricted to mineralized connective tissues of bones and teeth where it has been associated with mineral crystal formation. However, recent studies have revealed ectopic expression of BSP in various lesions, including oral and extraoral carcinomas, in which it has been associated with the formation of microcrystalline deposits and the metastasis of cancer cells to bone. To develop a model to study the induction of BSP in carcinoma development, BSP expression in squamous-cell carcinomas induced by chemical carcinogen in the hamster cheek-pouch epithelium was investigated. Hamster BSP cDNA was first isolated and characterized, then used to prepare probes for Northern and in situ hybridization. The protein sequence of hamster BSP displayed 86% amino acid identity with a consensus mammalian BSP sequence and retained polyglutamate sequences, the RGD sequence and sites of phosphorylation, glycosylation and sulphation. The tissue-specific expression of hamster BSP mRNA and protein was confirmed by in situ hybridization and immunolocalization in developing tissues. Squamous-cell carcinomas induced in the buccal pouches of 5-week-old male Syrian golden hamsters treated with chemical carcinogen had BSP mRNA and BSP in the proliferating neoplastic epithelium. In contrast, neither BSP mRNA nor the protein could be detected in the stroma within which islands of the transformed tissue had formed. Thus, the hamster cheek pouch is a well-characterized model that can be used to study the induced expression of BSP in association with the development of squamous-cell carcinomas.

Promotive effect of diethylstilbestrol on urethan-induced mouse lung tumorigenesis

The effect of diethylstilbestrol (DES) on urethan-induced mouse lung tumorigenesis was assessed by a single intraperitoneal injecting of urethan (50 mg/kg) or/and multi intramuscular injecting of DES (5 or 50 mg/kg). All mice were sacrificed 18 weeks after administration, and the lung tumors were examined histopathologically. DES did not produce an elevated lung tumor response when administered alone, but it produced a statistically significant enhancement of incidence of tumors, average number of tumors, incidence of cancers and constituent ratio of malignant tumors when given in conjunction with urethan. The results indicated that DES may be a promoter in lung tumor formation.

Effect of strenuous arm exercise on oxidized-LDL-potentiated platelet activation in individuals with spinal cord injury

This study investigates how strenuous arm exercise affects oxidized-low density lipoprotein (O(X)-LDL) mediated-platelet activation in patients with SCI. Ten patients with SCI and ten age- and sex-matched healthy subjects exercised strenuously using an arm crank ergometer. The following measurements were taken both when the subjects were at rest, and immediately after exercise: plasma lipid profile, O(X)-LDL mediated platelet aggregability and [Ca(2+)]i, urinary 11-dehydro-thromboxane B2 (11-dehydro-TXB2) and 8-iso-prostaglandin F(2alpha), (8-iso-PG F(2alpha)) contents, and plasma NO metabolite (nitrite plus nitrate) level. Based on these measurements, the major findings of this study can be summarized as follows: 1) the SCI group had higher urinary 8-iso-PGF(2alpha) and 11-dehydro-TXB2 contents, but a lower plasma nitrite plus nitrate level than the control group; 2) at rest, the SCI group had a higher platelet aggregability and [Ca(2+)]i, and O(X)-LDL-potentiated platelet activation than the control group; 3) O(X)-LDL-potentiated platelet aggregation was enhanced by strenuous arm exercise in both groups, but the effect of exercise was more pronounced in the SCI group than in the control group; 4) treating the platelet with L-arginine inhibited O(X)-LDL-potentiated platelet activation in both groups. The study concludes that individuals with SCI had more extensive resting and exercise-enhanced O(X)-LDL-potentiated platelet activation and greater amounts of preformed lipid peroxides than those without SCI. Therefore, supplementation therapy with antioxidants may be needed for patients with SCI, especially in a strenuous arm exercise period.

Effects of metabolites of benzo(a)pyrene on unschedule DNA synthesis in BALB/3T3 cell line

In order to explore the damage from metabolites of benzo(a)pyrene on DNA of mammalian cells, the effects of four metabolites of benzo(a)pyrene (anti-BPDE, syn-BPDE, 3-OH-BP and 9-OH-BP) on synthesis of DNA and unschedule DNA synthesis (UDS) in BALB/3T3 cells were assayed, by methods of single-labeling and double-labeling. The results showed that all of the four agents were able to increase the synthesis of DNA, but only three of them (apart from syn-BPDE) induced UDS in BALB/3T3 cells. The above indicates that the metabolites of benzo(a)pyrene are able to damage DNA in BALB/3T3 cells, and that this effect may be relative to the sterical structure of metabolites of benzo(a)pyrene.

Biological effects of cementum and bone extracts on human periodontal fibroblasts

BACKGROUND

Non-collagenous proteins of mineralized tissues play important roles in bone induction during mineralization and in regulating the activity of many types of mesenchymal cells. This study was conducted to determine the effects of acetic acid extracts of bone and cementum on alkaline phosphatase (ALPase) activity and in vitro mineralization of cultured human periodontal fibroblasts (hPF).

METHODS

Alveolar bone and cementum obtained from clinically healthy subjects were extracted by a solution containing 0.5 M acetic acid and enzyme inhibitors. Osteoblastic phenotypes of hPF were assayed by ALPase activity, gene expression of bone marker proteins, and the ability to produce in vitro mineralization in culture media containing 50 microg/ml ascorbic acid, 10 mM sodium beta-glycerophosphate, and 10(-7) M dexamethasone. The effects of cementum and bone extracts on the expression of osteoblastic phenotypes in hPF were also determined.

RESULTS

Many protein components, varying in molecular weight from 10 to 14 to 120 kDa, were detectable in 10% SDS-PAGE of both cementum and alveolar bone extracts. The hPF cells were found to exhibit a moderate ALPase activity when compared with rat osteosarcoma (ROS) 17/2.8 cells under the same experimental conditions. Gene expression for ALPase, osteocalcin bone sialoprotein, osteopontin, and BMP-7 at mRNA message was detected by RT-PCR in hPF and ROS 17/2.8 cells. The confluent hPF and ROS 17/2.8 cells showed evidence of calcium deposition in the extracellular milieu at 30 and 15 to 30 days' cultures, respectively, under a mineralization medium. The hPF appeared to form mineralized foci with morphological characteristics different from the mineralized nodules produced by ROS 17/2.8 cells. The addition of low concentrations (5 microg/ml) of either cementum or bone extract produced an increase in the size and number of mineralization spots, as well as greater ALPase activity in both hPF and ROS 17/2.8 cultures during the observation periods.

CONCLUSIONS

These results suggest that hPF possess certain mineralizing phenotypes, and that acetic acid extracts of bone and cementum contain components capable of stimulating osteogenic differentiation of hPF.

[Interleukin-2 stimulates the proliferation of cultured RC-4B/C pituitary adenoma cell line]

The aim of the present study was to investigate whether interleukin-2 (IL-2) is involved in the proliferation control of the cultured RC-4B/C cell, which is a derived pituitary adenoma cell line of the rat. The level of cell proliferation was estimated by assessing (3)H-thymidine ((3)H-TdR) incorporation rate. IL-2 (10 1000 U/ml) significantly stimulated (3)H-TdR incorporation into the cell line in a dose-dependent manner. Specific PTK inhibitor tyrphostin (1 micromol/L) suppressed RC-4B/C cell proliferation and blocked the effect of IL-2 on RC-4B/C cells. After the PKA signaling pathway was inhibited by specific PKA inhibitor H-9 (1 micromol/L), the proliferation rate of RC-4B/C cells increased significantly. H-9 also enhanced the stimulation of IL-2 on RC-4B/C cell growth. Anti-estrogen tamoxifen (1 micromol/L) had no significant effect on the action of IL-2 on the proliferation of RC-4B/C cells. In conclusion, it is suggested that IL-2 modulates the proliferation of the cultured RC-4B/C pituitary adenoma cell line, and the action is closely related with the PTK and PKA signaling pathway.

Overexpression of C-terminal Src kinase blocks 14, 15-epoxyeicosatrienoic acid-induced tyrosine phosphorylation and mitogenesis

We have previously reported that 14,15-epoxyeicosatrienoic acid (14, 15-EET) is a potent mitogen for the renal epithelial cell line, LLCPKcl4. This mitogenic effect is dependent upon activation of a protein-tyrosine kinase cascade that results in activation of mitogen-activated protein kinase and phosphatidylinositol 3-kinase. Because of suggestive evidence that 14,15-EET also activated Src in these cells, we stably transfected LLCPKcl4 with an expression construct of the C-terminal Src kinase (CSK), which inhibits Src family kinase activity. In vitro Src kinase activity assays confirmed that in empty vector-transfected cells (Vector cells), 14, 15-EET increased Src kinase activity, while in clones overexpressing CSK mRNA and immunoreactive protein (CSK cells), 14,15-EET-induced activation of Src was almost completely blocked (94% inhibition). Of interest, epidermal growth factor (EGF) and fetal bovine serum (FBS) also increased Src activity in Vector cells, but not in CSK cells, further confirming the ability of CSK overexpression to prevent Src activation. CSK cells failed to increase [(3)H]thymidine incorporation in response to exogenous 14,15-EET. In contrast, both EGF and FBS significantly increased [(3)H]thymidine incorporation in CSK cells. Immunoprecipitation with anti-phosphotyrosine antibodies and immunoblotting with an antibody against extracellular signal-regulated kinase (ERK) indicated that in CSK cells, 14,15-EET failed to activate ERK1 and ERK2; however, EGF- and FBS-induced activation of ERKs was not different from that seen in Vector cells. In Vector cells, the 14,15-EET-stimulated tyrosine phosphorylation of ERKs was blocked by pretreatment with 1 microm PP2, a selective inhibitor of Src kinases. The present study demonstrates that 14, 15-EET exerts its mitogenic effects predominantly through a Src kinase-mediated pathway, which is the most upstream signaling step determined to date in the 14,15-EET-activated tyrosine kinase cascade in renal epithelial cells.

Role of chronic exercise in decreasing oxidized LDL-potentiated platelet activation by enhancing platelet-derived no release and bioactivity in rats

This study investigates how chronic exercise affects Ox-LDL mediated-platelet activation. Five-week-old male Wistar rats were assigned to either control or trained groups. Trained rats were treadmill-trained for 10 weeks after familiarization. The following measurements were taken in both control and trained groups: plasma lipid profile, oxidation of LDL, platelet adhesiveness, aggregability, cGMP contents, plasma and platelet-NO metabolite (nitrite plus nitrate) levels, and urinary 8-iso-prostaglandin F2alpha (8-iso-PG F2alpha) levels. Based on those measurements, major findings in this study can be summarized as follows: 1) the trained group prolonged the lag time of isolated LDL subjected to copper-induced in vitro oxidation significantly longer than the control group; 2) although having higher plasma and platelet derived-NO metabolite levels, the trained group had lower urinary excretion of 8-iso-PGF2alpha than the control group; 3) the trained group had a lower platelet adhesiveness and aggregability and higher platelet derived-NO metabolite and cGMP productions than the control group; 4) the trained group had a lower Ox-LDL-potentiated platelet adhesiveness and aggregability and Ox-LDL-attenuated NO metabolite and cGMP productions in platelet than the control group; and 5) treating the platelet with L-arginine inhibited Ox-LDL-potentiated platelet activation in both control and trained groups. Results in this study demonstrate that amounts of preformed lipid peroxides decrease while NO production (which acts as an antioxidant) is significantly increased after chronic exercise. Moreover, exercise training decreases Ox-LDL-potentiated platelet activation most likely by enhancing platelet-derived NO release and bioactivity.

Effect of exercise training on oxidized LDL-mediated platelet function in rats

This study investigates how exercise training affects Oxidized LDL (Ox-LDL) mediated-platelet activation. Five-week-old male Wistar rats were assigned to either control or trained groups. Trained rats were treadmill-trained for 10 weeks after familiarization. The following measurements were taken in both control and trained groups: Ox-LDL-mediated platelet aggregability and [Ca2+]i, plasma and platelet-derived nitric oxide (NO) metabolite (nitrite plus nitrate) levels, and antiaggregating activity of NO derived from endothelial cells. Based on those measurements, major findings in this study can be summarized as follows: 1) the trained group had a higher plasma -NO metabolite level than the control group; 2) the trained group had a lower platelet aggregability and [Ca2+]i elevation and a higher platelet derived-NO metabolite level than the control group; 3) the trained group had lower Ox-LDL-potentiated platelet aggregability and [Ca2+]i elevation and Ox-LDL-attenuated NO metabolite in platelet than the control group; 4) treating the platelet with L-arginine inhibited Ox-LDL-potentiated platelet activation in both control and trained groups; 5) Ox-LDL enhances platelet aggregation directly although impairing NO bioactivity but not guanylate cyclase activity in both control and trained groups. Results in this study demonstrate that exercise training decreases Ox-LDL-potentiated platelet activation most likely by enhancing platelet-derived NO release.