Fibroblasts inhibit osteogenesis by regulating nuclear-cytoplasmic shuttling of YAP in mesenchymal stem cells and secreting DKK1

BACKGROUND

Fibrous scars frequently form at the sites of bone nonunion when attempts to repair bone fractures have failed. However, the detailed mechanism by which fibroblasts, which are the main components of fibrous scars, impede osteogenesis remains largely unknown.

RESULTS

In this study, we found that fibroblasts compete with osteogenesis in both human bone nonunion tissues and BMP2-induced ectopic osteogenesis in a mouse model. Fibroblasts could inhibit the osteoblastic differentiation of mesenchymal stem cells (MSCs) via direct and indirect cell competition. During this process, fibroblasts modulated the nuclear-cytoplasmic shuttling of YAP in MSCs. Knocking down YAP could inhibit osteoblast differentiation of MSCs, while overexpression of nuclear-localized YAP-5SA could reverse the inhibition of osteoblast differentiation of MSCs caused by fibroblasts. Furthermore, fibroblasts secreted DKK1, which further inhibited the formation of calcium nodules during the late stage of osteogenesis but did not affect the early stage of osteogenesis. Thus, fibroblasts could inhibit osteogenesis by regulating YAP localization in MSCs and secreting DKK1.

CONCLUSIONS

Our research revealed that fibroblasts could modulate the nuclear-cytoplasmic shuttling of YAP in MSCs, thereby inhibiting their osteoblast differentiation. Fibroblasts could also secrete DKK1, which inhibited calcium nodule formation at the late stage of osteogenesis.

Red cell distribution in critically ill patients with chronic obstructive pulmonary disease

BACKGROUND

Red blood cell distribution width (RDW) is associated with increased mortality risk in patients with chronic obstructive pulmonary disease (COPD). However, limited data are available for critically ill patients with COPD.

METHODS

Data from the Medical Information Mart for Intensive Care III V1.4 database were analyzed in this retrospective cohort research. The International Classification of Diseases codes were used to identify critically ill patients with COPD. The first value of RDW was extracted within the first 24 h after intensive care unit admission. The endpoint was 28-day all-cause mortality. Multivariable logistic regression analysis was performed to examine the relationship between RDW and 28-day mortality. Age, sex, ethnicity, anemia status, comorbidities, clinical therapy, and disease severity score were considered for subgroup analysis.

RESULTS

A total of 2,344 patients were included with mean (standard deviation) age of 72.3 (11.3) years, in which 1,739 (53.6%) patients were men. The increase in RDW was correlated with an increased risk of 28-day mortality in the multivariate logistic regression model (odds ratio [OR] 1.15; 95% confidence interval [CI] 1.09-1.21). In comparison with the low-RDW group, the middle and high-RDW groups tended to have higher risks of 28-day all-cause mortality (OR [95% CI] 1.03 [0.78-1.34]; OR [95% CI] 1.70 [1.29-2.22]; P trend < 0.0001). Subgroup analyses show no evidence of effect modifications on the correlation of RDW and 28-day all-cause mortality.

CONCLUSION

An increase in RDW was associated with an increased risk of 28-day all-cause mortality in critically ill patients with COPD. Further studies are required to investigate this association.

Bifunctional Role of Monocyte Subsets in Modulating Radiotherapy Combined Intra-Tumor αCD40 Agonist Induced Abscopal Effect

PURPOSE/OBJECTIVE(S)

Abscopal effect induced by radiotherapy and immune checkpoint blockade is a promising yet far from satisfactory strategy in clinical. The underlying immune mechanism, especially driven by monocytes remains poorly undefined. Monocytes consist of two phenotypically and functionally distinct subsets distinguished by expression of chemokine receptors CCR2 and CX3CR1: classical inflammatory Ly6ChiCCR2hi monocytes and nonclassical patrolling Ly6CloCCR2loCX3CR1hi monocytes. Monocytes differentiate and transit to other myeloid cells such as dendritic cells and macrophages according to various environmental cues. Herein we investigated the roles of monocyte subsets in modulating tumor control consisting of combination RT and myeloid checkpoint agonist αCD40 to specifically ignite myeloid cell activation.

MATERIALS/METHODS

To establish abscopal model, contralateral tumors were implanted in each mouse, while only one side were treated with RT (8 Gy × 3) + αCD40 agonist (50 μg, intra-tumor). Tumor volume and mice survival were compared in each group (control, RT, αCD40 and RT + αCD40). Ccr2RFP/+ Cx3cr1GFP/+ (R2 × 3), Ccr2RFP/RFPCx3cr1+/+ (R2-KO) and Ccr2+/+Cx3cr1GFP/GFP (X3-KO) mice were used for cell tracking and to dissect chemokine receptor CCR2 and CX3CR1 on monocyte. Tumor infiltrating immune cells were analyzed by flowcytometry and RNA-seq.

RESULTS

RT combined with αCD40 significantly dampened tumor growth on both ipsilateral and contralateral sides in abscopal model (p< 0.01), accompanied by upregulation of chemokine receptors CCR2 and CX3CR1 on myeloid cells were both increased in tumor and peripheral blood. Chemokine ligands CCL2, CCL3, CCL5, CCL7, CCL12 and CX3CL1 were upregulated in tumor after RT and αCD40 treatment, recruiting CCR2 and CX3CR1 expressing monocytes in situ. To elucidate the roles of CCR2 and CX3CR1 in mediating local and systemic anti-tumor immunity, R2 × 3, R2-KO and X3-KO mice with combined treatment were used. Tumor size on ipsilateral leg were similar among groups. However, tumor growth was significantly delayed on contralateral side in X3-KO mice while accelerated in R2-KO mice compared with that in R2 × 3 mice. Mechanistically, remarkable decrease of antigen presenting dendritic cells (MHCII+Ly6ChiCD11c+) were observed in R2-KO mice. Moreover, phagocytosis was strengthened in macrophages (F4/80+CD11b+) of X3-KO mice.

CONCLUSION

CX3CR1 deletion ignite anti-tumor immunity elicited by RT and αCD40 through enhanced phagocytosis in macrophages, while CCR2 deletion renders inferior tumor control through reduction of dendritic cells. Preferential targeting nonclassical patrolling monocyte may lead to enhanced local and systemic tumor control.

Acupuncture combined with exercise training at different time points on nerve repair of cerebral ischemia-reperfusion injury in rats and its effects on the expressions of Nestin, bFGF and EGF

OBJECTIVE

The aim of the study was to observe the neuroreparative effect of electroacupuncture in rats with cerebral ischemia-reperfusion injury, and to explore the difference in the therapeutic effect of acupuncture on different acupoint groups after cerebral ischemia-reperfusion.

MATERIALS AND METHODS

Experimental rats were randomly divided into: sham operation group, model group, electroacupuncture group, rehabilitation group, and Diankang group (electroacupuncture + rehabilitation training). There were 24 rats in each group, and the focal cerebral ischemia-reperfusion model was established by Zea-Longa suture method. After modeling, it took 4 hours to electroacupuncture at Baihui and Dazhui points, which was used to observe the changes of nerve function in rats with signs of keel nerve function defect. Protein expression was detected by immunohistochemistry.

RESULTS

Compared with the model group, the EA 3d, 7d, 10d groups and the rehabilitation group had no significant difference in promoting the expression of Nestin (p>0.05). There was a significant difference (p<0.01). After cerebral ischemia-reperfusion injury, the expression of bFGF and EGF on the ischemic side was stronger. The peak of bFGF expression appeared earlier, and the peak of EGF expression appeared later. The expression of bFGF and EGF in cerebral ischemic cortex at different time points of ischemia in electroacupuncture group, rehabilitation group and Diankang group was increased, and the response was enhanced. The effect of Diankang group on the upregulation of bFGF and EGF was more significant (p<0.01, p<0.05).

CONCLUSIONS

Under the influence of different effects, Diankang is superior to simple treatment in improving ischemic neurological dysfunction. This may be related to the fact that Diankang can promote the proliferation of neural stem cells and the expression of neurotrophic factors on the ischemic side of the rat brain.

[Effects and mechanism of pressure treatment on hemodynamic changes in patients with hypertrophic scar secondary to extensive burns]

Objective: To investigate the hemodynamic changes of the main arteries and veins of the extremities and the heart in patients with hypertrophic scar secondary to extensive burns after pressure treatment, and to analyze the relevant mechanisms. Methods: A retrospective before-after self-control study was conducted. From January 2017 to February 2022, 37 patients with hypertrophic scar secondary to extensive burns who met the inclusion criteria were hospitalized in the Burn Rehabilitation Department of Guangdong Industrial Injury Rehabilitation Hospital, including 25 males and 12 females, aged 23-52 years. The patients were admitted to the hospital within 12 weeks after wound healing, and within one week after admission, rehabilitation therapists, occupational therapists, and tailors custom-made pressure products such as full-body pressure garment, pressure pants, vests, split finger gloves, split finger socks, hoods, and plastic collars, with the pressure at each part maintained at 2.67-4.00 kPa when wearing. Before the first treatment with pressure products (hereinafter referred to as before pressure treatment) and at 1 h of the first treatment with pressure products (hereinafter referred to as 1 h of pressure treatment), color Doppler ultrasonography was performed to check the pulse rate of the axillary artery, the lumen diameter, peak systolic velocity (PSV), and resistance index of the axillary artery and femoral artery on the left side, the lumen diameter, cross-sectional area, and average blood flow velocity of the axillary vein and femoral vein, and the mitral valve E peak, mitral valve A peak, tricuspid valve E peak, aortic valve PSV, and pulmonary valve PSV of the heart; an optical chromatographic skin detector was used to detect the red color, red pigment, and surface brightness of the scar on the back of the hand to reflect the filling and distribution of the scar microvessels. Data were statistically analyzed with paired sample t test. Results: Compared with those before pressure treatment, the PSV of the axillary artery of patients was significantly slowed down at 1 h of pressure treatment (t=55.42, P<0.01); the average blood flow velocity of the axillary vein was significantly accelerated (t=-60.50, P<0.01); the pulse rate, lumen diameter, and resistance index of the axillary artery, as well as the lumen diameter and cross-sectional area of the axillary vein did not change obviously (P>0.05); the average blood flow velocity of the femoral vein was significantly accelerated (t=-80.52, P<0.01); the lumen diameter, PSV, and resistance index of the femoral artery, as well as the lumen diameter and cross-sectional area of the femoral vein had no significant change (P>0.05); the mitral valve E peak and mitral valve A peak of the heart decreased significantly (with t values of 10.71 and 21.96, respectively, P<0.01); the tricuspid valve E peak of the heart increased significantly (t=7.57, P<0.01); the PSV of the aortic valve and pulmonary valve of the heart did not change obviously (P>0.05). At 1 h of pressure treatment, the red color and red pigment values of the scar on the back of the hand of patients were 15.3±1.1 and 16.8±1.2, respectively, which were significantly lower than 24.5±1.3 and 23.8±1.2 before pressure treatment (with t values of 8.32 and 8.04, respectively, P<0.01). The brightness value of the scar surface on the back of the hand of patients at 1 h of pressure treatment was similar to that before pressure treatment (P>0.05). Conclusions: After pressure treatment for the hypertrophic scar in patients secondary to extensive burn, the average blood flow velocity of the axillary vein and femoral vein in patients are obviously accelerated, the PSV of the axillary artery is significantly slowed down, the peak values of mitral valve E and mitral valve A of the heart are significantly decreased, and the tricuspid valve E peak is significantly increased. These hemodynamic changes may be related to the reduction of microvascular blood flow in the local area of scar after systemic pressure treatment.

A minimally invasive bipolar surgical approach for the treatment of patellar fracture using the tension-band wiring technique

Objective

Minimally invasive surgical techniques are becoming increasingly popular for the treatment of traumatic injuries. Although some minimally invasive techniques in the management of patellar fractures have been reported, the limited exposure in such methods may cause technical difficulties during surgery and restrict their wide application. In this context, this study aims to introduce a bipolar incision and assess the clinical outcomes of patellar fractures treated via this type of incision.

Materials and methods

Patients who suffered patellar fractures and who received surgical treatment via bipolar incision between 2018 and 2020 in our hospital were retrospectively reviewed and included in this study. The clinical and radiological records of all patients were reviewed. A classification of the fractures was done and intraoperative parameters, Visual Analog Scale (VAS) score, knee range of motion, and the Hospital for Special Surgery (HSS) knee score of the patients were evaluated and summarized.

Results

The study included 19 patients who met the inclusion criteria. All patellar fractures were operated through the minimally invasive bipolar surgical approach. The mean time of operation was 69.0 ± 8.5 min. The mean time to union was 12.8 ± 2.1 weeks. The average total knee range of motion was 131.8 ± 4.4°, and the average HSS score was 97.1 ± 2.6 at 1-year post-operation. No surgical-related complications were observed.

Conclusions

The knee functional outcomes were favorable when patellar fractures were treated through the minimally invasive bipolar incision method. This bipolar surgical approach was found to be a feasible method for treating patellar fractures.

Platycodon D-induced A549 cell apoptosis through RRM1-regulated p53/VEGF/MMP2 pathway

BACKGROUND

Lung cancer is one of the leading causes of cancer-related deaths worldwide. Platycodin D (PD), a major pharmacological constituent from the Chinese medicinal herb named Platycodonis Radix, has shown potent anti-tumor activity. Also, it is also reported that PD could inhibit cellular growth in the non-small-cell lung carcinoma (NSCLC) A549 cell line. However, the underlying mechanism is not fully clarified.

METHODS

Cell proliferation was measured by MTT assay. Annexin V and propidium iodide (PI) assay were employed to study the apoptosis effects of PD on A549 cells. Western blot analysis was used to evaluate protein expression. Also, we used a siRNA against p53, as well as a plasmid-based RRM1 over-expression to investigate their functions.

RESULTS

It demonstrated PD inhibited A549 cell proliferation in a dose- and time-dependent manner. Further investigations showed that PD induced cell apoptosis, which was supported by dose-dependent and time-dependent caspase-3 activation and p53/VEGF/MMP2 pathway regulation. Also, PD demonstrated the inhibition effect of ribonucleotide reductase M1 (RRM1), whose role in various tumors is contradictory. Remarkably, in this work, RRM1 overexpression in A549 cells could have a negative impact on the regulation of the p53/VEGF/MMP2 pathway induced by PD treatment. Note as well that RRM1 overexpression also attenuated cell apoptosis and inhibition of cell proliferation of A549 treated with PD.

CONCLUSION

The results suggested that PD could inhibit A549 cell proliferation and induce cell apoptosis by regulating p53/VEGF/MMP2 pathway, in which RRM1 plays an important role directly.

Stattic sensitizes osteosarcoma cells to epidermal growth factor receptor inhibitors via blocking the interleukin 6-induced STAT3 pathway

Osteosarcoma (OS), the most common malignant bone tumor with high metastatic potential, frequently affects children and adolescents. Epidermal growth factor receptor (EGFR)-targeted tyrosine kinase inhibitors exhibit encouraging anti-tumor activity for patients with solid tumors, whereas their effects on OS remain controversial. In the present study, we aimed to elucidate the anti-tumor activity of gefitinib for OS, as well as to explore the underlying mechanisms. Gefitinib inhibits cell viability, tumor growth, cell migration, and invasion and promotes cell apoptosis and G1 cycle arrest in OS at a relatively high concentration via suppressing the PI3K/Akt and ERK pathways. However, gefitinib treatment results in the feedback activation of signal transducer and activator of transcription 3 (STAT3) induced by interleukin 6 (IL-6) secretion. Combined treatment with gefitinib and stattic, an inhibitor for STAT3 phosphorylation, engenders more evident inhibitory effects on cell proliferation, migration, and invasion and promotive effects on cell apoptosis and G1 phase arrest in OS, compared with the single exposure to gefitinib or stattic. Western blot analysis demonstrates that stattic treatment in gefitinib-treated OS abrogates the IL-6-induced STAT3 activation and subsequently further restrains the activities of EGFR, Akt, and ERK pathways in tumor cells. This study confirms that the EGFR inhibitor of gefitinib has moderate anti-tumor effects on OS through IL-6 secretion-mediated STAT3 activation. Additional administration of stattic in EGFR-targeted therapies may contribute to improve the efficacy for OS.

Inhibition of BUB1 suppresses tumorigenesis of osteosarcoma via blocking of PI3K/Akt and ERK pathways

Osteosarcoma (OS) is a primary malignant bone tumour that mainly affects teenagers, with patients displaying poor prognosis. Budding uninhibited by benzimidazoles 1 (BUB1), a type of serine/threonine kinase that is linked to pro-tumorigenic phenomena, has not been well studied in OS. Hence, this study aimed to explore the role of BUB1 in OS. The expression of BUB1 in OS specimens and cell lines was assessed using immunohistochemistry and Western blot analysis. Univariate and multivariate analyses were applied to evaluate the impact of BUB1 on patient survival. Cell counting kit-8, wound-healing and Transwell assays, as well as flow cytometry, were used to investigate the influence of BUB1 inhibition on OS in vitro. Moreover, a tumour xenograft model was established to investigate the in vivo effect of BUB1 inhibition on OS tumour growth. Results showed that BUB1 was overexpressed in OS specimens and cell lines. Furthermore, BUB1 overexpression was closely associated with the poor clinical outcomes of patients with OS. Inhibition of BUB1 markedly suppressed cell proliferation and tumour growth, cell migration, invasion and induced cell apoptosis of OS by blocking the PI3K/Akt and ERK signalling pathways. Thus, our study suggested that overexpression of BUB1 protein contributed to poor survival of OS patients and that inhibition of BUB1 resulted in considerable anti-tumour activity associated with proliferation, migration, invasion and apoptosis of OS.

Sulfiredoxin-1 protects spinal cord neurons against oxidative stress in the oxygen-glucose deprivation/reoxygenation model through the bax/cytochrome c/caspase 3 apoptosis pathway

BACKGROUND

Spinal cord ischemia/reperfusion injury is a common clinical, pathophysiological phenomenon with complex molecular mechanisms. Currently, there are no therapeutics available to alleviate the same. This study investigates the protective effects of sulfiredoxin-1 (Srxn 1) on spinal cord neurons following exposure to oxygen-glucose deprivation/reoxygenation (OGD/R) treatment.

MATERIALS AND METHODS

Primary spinal cord neurons were cultured, detected by anti-tubulin βⅢ, and transfected with adeno-associated virus (AAV)-Srxn 1 to overexpress Srxn 1. They were identified by their morphology and CCK-8 assay. The superoxide dismutase level was measured by superoxide dismutase assay. Malondialdehyde level was measured by malondialdehyde assay. The apoptosis ratio was calculated by Hoechst 33342 and Annexin V-PE/7-AAD staining. Mitochondrial transmembrane potential (Δψm) was detected by tetramethylrhodamine-methyl ester-perchlorate (TMRM) staining. The mRNA expression levels of Srxn 1 and caspase 3 were detected by quantitative reverse transcription-polymerase chain reaction, and the protein expression levels of Srxn 1, bax, bcl-2, cytosolic cytochrome c, and caspase 3 were detected by western blotting.

RESULTS

AAV-Srxn 1 up-regulated mRNA and protein levels of Srxn 1 in spinal cord neurons. Following exposure to OGD/R, overexpression of Srxn 1 improved the neuronal viability, alleviated the neuron apoptosis, enhanced the mitochondrial transmembrane potential, increased the SOD level, decreased the MDA level, inhibited the expression of cytosolic cytochrome c, bax, and caspase 3, and promoted the expression of bcl-2.

CONCLUSION

Srxn 1 plays a significant role in anti-apoptosis of spinal cord neurons, and Srxn 1 may be a potential therapeutic target for spinal cord I/R injury.

Bulk Fermi Surfaces of the Dirac Type-II Semimetallic Candidates MAl_{3} (Where M=V, Nb, and Ta)

We report a de Haas-van Alphen (dHvA) effect study on the Dirac type-II semimetallic candidates MAl_{3} (where, M=V, Nb and Ta). The angular dependence of their Fermi surface (FS) cross-sectional areas reveals a remarkably good agreement with our first-principles calculations. Therefore, dHvA supports the existence of tilted Dirac cones with Dirac type-II nodes located at 100, 230 and 250 meV above the Fermi level ϵ_{F} for VAl_{3}, NbAl_{3} and TaAl_{3} respectively, in agreement with the prediction of broken Lorentz invariance in these compounds. However, for all three compounds we find that the cyclotron orbits on their FSs, including an orbit nearly enclosing the Dirac type-II node, yield trivial Berry phases. We explain this via an analysis of the Berry phase where the position of this orbit, relative to the Dirac node, is adjusted within the error implied by the small disagreement between our calculations and the experiments. We suggest that a very small amount of doping could displace ϵ_{F} to produce topologically nontrivial orbits encircling their Dirac node(s).

Heme oxygenase-1 protects spinal cord neurons from hydrogen peroxide-induced apoptosis via suppression of Cdc42/MLK3/MKK7/JNK3 signaling

The mechanisms by which oxidative stress induces spinal cord neuron death has not been completely understood. Investigation on the molecular signal pathways involved in oxidative stress-mediated neuronal death is important for development of new therapeutics for oxidative stress-associated spinal cord disorders. In current study we examined the role of heme oxygenase-1 (HO-1) in the modulation of MLK3/MKK7/JNK3 signaling, which is a pro-apoptotic pathway, after treating primary spinal cord neurons with H2O2. We found that MLK3/MKK7/JNK3 signaling was substantially activated by H2O2 in a time-dependent manner, demonstrated by increase of activating phosphorylation of MLK3, MKK7 and JNK3. H2O2 also induced expression of HO-1. Transduction of neurons with HO-1-expressing adeno-associated virus before H2O2 treatment introduced expression of exogenous HO-1 in neurons. Exogenous HO-1 reduced phosphorylation of MLK3, MKK7 and JNK3. Consistent with its inhibitory effect on MLK3/MKK7/JNK3 signaling, exogenous HO-1 decreased H2O2-induced neuronal apoptosis and necrosis. Furthermore, we found that exogenous HO-1 inhibited expression of Cdc42, which is crucial for MLK3 activation. In addition, HO-1-induced down-regulation of MLK3/MKK7/JNK3 signaling might be related to up-regulation of microRNA-137 (mir-137). A mir-137 inhibitor alleviated the inhibitory effect of HO-1 on JNK3 activation. This inhibitor also increased neuronal death even when exogenous HO-1 was expressed. Therefore, our study suggests a novel mechanism by which HO-1 exerted its neuroprotective efficacy on oxidative stress.

Heme Oxygenase-1 Inhibits Neuronal Apoptosis in Spinal Cord Injury through Down-Regulation of Cdc42-MLK3-MKK7-JNK3 Axis

The mechanism by which spinal cord injury (SCI) induces neuronal death has not been thoroughly understood. Investigation on the molecular signal pathways involved in SCI-mediated neuronal apoptosis is important for development of new therapeutics for SCI. In the current study, we explore the role of heme oxygenase-1 (HO-1) in the modulation of mixed lineage kinase 3/mitogen-activated protein kinase kinase/cJUN N-terminal kinase 3 (MLK3/MKK7/JNK3) signaling, which is a pro-apoptotic pathway, after SCI. We found that MLK3/MKK7/JNK3 signaling was activated by SCI in a time-dependent manner, demonstrated by increase in activating phosphorylation of MLK3, MKK7, and JNK3. SCI also induced HO-1 expression. Administration of HO-1-expressing adeno-associated virus before SCI introduced expression of exogenous HO-1 in injured spinal cords. Exogenous HO-1 reduced phosphorylation of MLK3, MKK7, and JNK3. Consistent with its inhibitory effect on MLK3/MKK7/JNK3 signaling, exogenous HO-1 decreased SCI-induced neuronal apoptosis and improved neurological score. Further, we found that exogenous HO-1 inhibited expression of cell division cycle 42 (Cdc42), which is crucial for MLK3 activation. In vitro experiments indicated that Cdc42 was essential for neuronal apoptosis, while transduction of neurons with HO-1-expressing adeno-associated virus significantly reduced neuronal apoptosis to enhance neuronal survival. Therefore, our study disclosed a novel mechanism by which HO-1 exerted its neuroprotective efficacy. Our discovery might be valuable for developing a new therapeutic approach for SCI.

Dynamic change in natural killer cell type in the human ocular mucosa in situ as means of immune evasion by adenovirus infection

The most severe form of virus-induced inflammation at the ocular surface is epidemic keratoconjunctivitis (EKC), often caused by group D human adenoviruses (HAdVs). We investigated the dynamics and mechanisms of changes in natural killer (NK) cell types in the human ocular mucosal surface in situ over the course of infection. In the acute phase of infection, the mature CD56(dim)NK cells that comprise a major subpopulation in the normal human conjunctiva are replaced by CD56(bright)NK cells recruited to the ocular surface by chemokines produced by the infected epithelium, and NKG2A-expressing CD56(dim) and CD56(bright) NK cells become the major subpopulations in severe inflammation. These NK cells attracted to the mucosal surface are however incapable of mounting a strong antiviral response because of upregulation of the inhibitory ligand human leukocyte antigen-E (HLA-E) on infected epithelium. Furthermore, group D HAdVs downregulate ligands for activating NK cell receptors, thus rendering even the mature NKG2A(-)NK cells unresponsive, an immune-escape mechanism distinct from other adenoviruses. Our findings imply that the EKC-causing group D HAdVs utilize these multiple pathways to inhibit antiviral NK cell responses in the initial stages of the infection.

146 CO-CULTURE OF EARLY CLEAVAGE STAGE IVP EMBRYOS WITH BOVINE OVIDUCT EPITHELIAL CELLS DOES NOT IMPROVE EMBRYO DEVELOPMENT OR PREGNANCY RATES

Pregnancy rates after the transfer of bovine IVP embryos are lower than that achieved after the transfer of MOET embryos. One reason may be that the relatively defined IVC (SOFaaBSA) culture system used in vitro is suboptimal for embryo development. We investigated whether the co-culture of early stage IVP embryos with bovine oviduct epithelial cell (BOEC) to Day 3 could provide some of the missing substrates and improve both embryo production and subsequent pregnancy rates after embryo transfer. COCs were collected by ovum pickup (OPU) from donor Brahman females, transported overnight at 38.5°C to the laboratory in HEPES-IVM media, then fertilized and cultured by our standard IVP methodology (Fry et al. 2003 Theriogenology 59, 446). Briefly, the IVC was carried out at 38.5°C in a humidified atmosphere of 5% CO2, 5% O2, 90% N2 in 4-well Nunc dishes in 500 μL of SOFaaBSA media overlayed by 500 μL of mineral oil. After 3 days of culture, the embryos were transferred to fresh IVC media and after 6 days placed in 5-mL Falcon tubes (Becton Dickinson Labware, Lincoln, NJ, USA) in fresh IVC media containing 2% FCS for overnight shipment. All grade 1 and 2 embryos were transferred to synchronized recipients on Day 7. Pregnancy diagnosis was between Days 50-90. In the BOEC treatment group, frozen aliquots of BOEC were thawed, seeded at 300,000 cells/mL, and grown for 2 days to 60-80% confluence in the Nunc wells in 500μL of DMEM/F12 media containing 10% FCS. On the first day of embryo culture, the media was removed and replaced by IVC media prior to the introduction of presumptive zygotes. After 3 days of co-culture, the embryos were transferred to fresh IVC media and thereafter cultured and transferred as for the Control group. In the Control group, 80 OPU sessions produced 1277 COCs (mean 16.0) of which 1064 (81.6%) cleaved producing 385 (33.7%) transferable embryos. Of the 337 embryos transferred to recipients (48 were vitrified), 141 (40.1%) resulted in pregnancies. In the BOEC group, 73 OPU sessions produced 1111 COCs (mean 15.2) of which 891 (80.2%) cleaved producing 388 (35%) transferable embryos that resulted in 161 (41.5%) pregnant recipients after transfer. Chi-square analysis showed no difference in either IVP embryo production or subsequent pregnancy rate between the Control group or the group where the IVP embryo was co-cultured for the first 3 days with BOEC.

Lack of association between HLA-A, -B and -DRB1 alleles and the development of SARS: a cohort of 95 SARS-recovered individuals in a population of Guangdong, southern China

Severe acute respiratory syndrome (SARS), caused by infection with a novel coronavirus (SARS‐CoV), was the first major novel infectious disease at the beginning of the 21st century, with China especially affected. SARS was characterized by high infectivity, morbidity and mortality, and the confined pattern of the disease spreading among the countries of South‐East and East Asia suggested the existence of susceptible factor(s) in these populations. Studies in the populations of Hong Kong and Taiwan showed an association of human leucocyte antigen (HLA) polymorphisms with the development and/or severity of SARS, respectively. The aim of the present study was to define the genotypic patterns of HLA‐A, ‐B and ‐DRB1 loci in SARS patients and a co‐resident population of Guangdong province, southern China, where the first SARS case was reported. The samples comprised 95 cases of recovered SARS patients and 403 unrelated healthy controls. HLA ‐A, ‐B and ‐DRB1 alleles were genotyped using polymerase chain reaction with sequence‐specific primers. The severity of the disease was assessed according to the history of lung infiltration, usage of assisted ventilation and occurrence of lymphocytopenia. Although the allelic frequencies of A23, A34, B60, DRB1*12 in the SARS group were slightly higher, and A33, ‐B58 and ‐B61 were lower than in the controls, no statistical significance was found when the Pc value was considered. Similarly, no association of HLA alleles with the severity of the disease was detected. Thus, variations in the major histocompatibility complex are unlikely to have contributed significantly to either the susceptibility or the severity of SARS in the population of Guangdong.

The effect of lidocaine on in vitro neutrophil and endothelial adhesion molecule expression induced by plasma obtained during tourniquet-induced ischaemia and reperfusion

BACKGROUND

Changes in neutrophil and endothelial adhesion molecule expression occur during perioperative ischaemia and reperfusion (I/R) injury. We investigated the effects of lidocaine on neutrophil-independent changes in neutrophil and endothelial adhesion molecule expression associated with tourniquet-induced I/R.

METHODS

Plasma was obtained from venous blood samples (tourniquet arm) taken before (baseline), during, 15 min, 2 and 24 h following tourniquet release in seven patients undergoing elective upper limb surgery with tourniquet application. Isolated neutrophils from healthy volunteers (n = 7) were pretreated in the presence or absence of lidocaine (0.005, 0.05 and 0.5 mg mL(-1) for 1 h, and then incubated with I/R plasma for 2 h. Human umbilical vein endothelial cells (HUVECs) were pretreated in the presence or absence of lidocaine (0.005, 0.05 and 0.5 mg mL(-1)) for 1 h, and then incubated with the plasma for 4 h. Adhesion molecule expression was estimated using flow cytometry. Data were analysed using ANOVA and post hoc Student-Newman-Keuls tests.

RESULTS

I/R plasma (withdrawn 15 min following tourniquet release) increased isolated neutrophil CD11b (P = 0.03), CD18 (P = 0.01) and endothelial intercellular adhesion molecule-1 (ICAM-1) (P = 0.008) expression compared to baseline. CD11b, CD18 and ICAM-1 expression on lidocaine (0.005 mg mL(-1)) treated neutrophils was similar to control. CD11b (P < 0.001), CD18 (P = 0.03) and ICAM-1 (P = 0.002) expression on lidocaine (0.05 mg mL(-1)) treated neutrophils and HUVECs was less than that on controls.

CONCLUSION

Increased in vitro neutrophil and endothelial cell adhesion molecule expression on exposure to plasma obtained during the early reperfusion phase is diminished by lidocaine at greater than clinically relevant plasma concentrations.

The effect of lidocaine on neutrophil CD11b/CD18 and endothelial ICAM-1 expression and IL-1beta concentrations induced by hypoxia-reoxygenation

BACKGROUND

Lidocaine has actions potentially of benefit during ischaemia-reperfusion. Neutrophils and endothelial cells have an important role in ischaemia-reperfusion injury.

METHODS

Isolated human neutrophil CD11b and CD18, and human umbilical vein endothelial cell (HUVEC) ICAM-1 expression and supernatant IL-1beta concentrations in response to hypoxia-reoxygenation were studied in the presence or absence of different concentrations of lidocaine (0.005, 0.05 and 0.5 mg mL(-1)). Adhesion molecule expression was quantified by flow cytometry and IL- 1beta concentrations by ELISA. Differences were assessed with analysis of variance and Student-Newman-Keuls as appropriate. Data are presented as mean+/-SD.

RESULTS

Exposure to hypoxia-reoxygenation increased neutrophil CD11b (94.33+/-40.65 vs. 34.32+/-6.83 mean channel fluorescence (MCF), P = 0.02), CD18 (109.84+/-35.44 vs. 59.05+/-6.71 MCF, P = 0.03) and endothelial ICAM-1 (146.62+/-16.78 vs. 47.29+/-9.85 MCF, P < 0.001) expression compared to normoxia. Neutrophil CD18 expression on exposure to hypoxia-reoxygenation was less in lidocaine (0.005 mg mL(-1)) treated cells compared to control (71.07+/-10.14 vs. 109.84+/-35.44 MCF, P = 0.03). Endothelial ICAM-1 expression on exposure to hypoxia-reoxygenation was less in lidocaine (0.005 mg mL(-1)) treated cells compared to control (133.25+/-16.05 vs. 146.62+/-16.78 MCF, P = 0.03). Hypoxia-reoxygenation increased HUVEC supernatant IL-1beta concentrations compared to normoxia (3.41+/-0.36 vs. 2.65+/-0.21 pg mL(-1), P = 0.02). Endothelial supernatant IL-1beta concentrations in lidocaine-treated HUVECs were similar to controls.

CONCLUSIONS

Lidocaine at clinically relevant concentrations decreased neutrophil CD18 and endothelial ICAM-1 expression but not endothelial IL-1beta concentrations.

The effect of aprotinin on hypoxia-reoxygenation-induced changes in neutrophil and endothelial function

BACKGROUND AND OBJECTIVE

An acute inflammatory response associated with cerebral ischaemia-reperfusion contributes to the development of brain injury. Aprotinin has potential, though unexplained, neuroprotective effects in patients undergoing cardiac surgery.

METHODS

Human neutrophil CD11 b/CD18, endothelial cell intercellular adhesion molecule-1 (ICAM-1) expression and endothelial interleukin (IL)-1beta supernatant concentrations in response to in vitro hypoxia-reoxygenation was studied in the presence or absence of aprotinin (1600 KIU mL(-1)). Adhesion molecule expression was quantified using flow cytometry and IL-1beta concentrations by enzyme-linked immunosorbent assay. Data were analysed using ANOVA and post hoc Student-Newman-Keuls test as appropriate.

RESULTS

Exposure to 60-min hypoxia increased neutrophil CD11b expression compared to normoxia (170+/-46% vs. 91+/-27%, P = 0.001) (percent intensity of fluorescence compared to time 0) (n = 8). Hypoxia (60 min) produced greater upregulation of CD11b expression in controls compared to aprotinin-treated neutrophils [(170+/-46% vs. 129+/-40%) (P = 0.04)] (n = 8). Hypoxia-reoxygenation increased endothelial cell ICAM-1 expression (155+/-3.7 vs. 43+/-21 mean channel fluorescence, P = 0.0003) and IL-1beta supernatant concentrations compared to normoxia (3.4+/-0.4 vs. 2.6+/-0.2, P = 0.02) (n = 3). Hypoxia-reoxygenation produced greater upregulation of ICAM- 1 expression [(155+/-3.3 vs. 116+/-0.7) (P = 0.001)] and IL-1beta supernatant concentrations [(3.4+/-0.3 vs. 2.6+/-0.1) (P = 0.01)] in controls compared to aprotinin-treated endothelial cell preparation (n = 3).

CONCLUSIONS

Hypoxia-reoxygenation-induced upregulation of neutrophil CD11b, endothelial cell ICAM-1 expression and IL-1beta concentrations is decreased by aprotinin at clinically relevant concentrations.

Effect of aprotinin on in vitro cerebral endothelial ICAM-1 expression induced by astrocyte-conditioned medium

BACKGROUND AND OBJECTIVE

Aprotinin administration may decrease the incidence of stroke associated with coronary artery bypass surgery by an unknown mechanism. Astrocytes exposed to hypoxia produce proinflammatory cytokines and upregulate intercellular adhesion molecule (ICAM)-1 on cerebral endothelium. This study investigated the effects of aprotinin on cerebral endothelial activation by hypoxic astrocytes in vitro.

METHODS

Mouse astrocytes were exposed to hypoxia in an anaerobic chamber for 4 h followed by reoxygenation for 24 h. Astrocyte-conditioned medium (ACM) collected from mouse astrocytes subjected to hypoxia/reoxygenation (HR) or normoxia were applied to mouse cerebral endothelial cell (MCEC) cultures for 4 and 24 h in normoxia. Endothelial cells were preincubated for 1 h with aprotinin (1600 KIU mL(-1)) prior to exposure to ACM. Flow cytometry was used to estimate endothelial ICAM-1 expression. Interleukin (IL)-1beta space concentrations in ACM were estimated with enzyme-linked immunosorbent assay (ELISA). Repeated comparisons were made using analysis of variance (ANOVA) and post hoc Tukey test as appropriate. P < 0.05 was considered significant. Data is presented as mean (standard deviation, SD).

RESULTS

MCEC ICAM-1 expression was greater after 24 h exposure to HR-ACM compared to normoxic-ACM (mean channel flouresence (MCF) 107.5 (4.5) vs. 74.3 (4.5), respectively, P < 0.001). ICAM-1 expression was decreased by aprotinin preincubation compared to control (MCF 91.0 (1.1) vs. 107.5 (2.1), P = 0.006). Supernatant IL-1beta concentrations in astrocytes exposed to HR were greater than those exposed to normoxia (7.1 (0.2) vs. 4.1 (0.2), P = 0.01).

CONCLUSIONS

This may be a neuroprotective mechanism associated with aprotinin administration.

The effect of clomethiazole on plasma concentrations of interleukin-6, -8, -1beta, tumor necrosis factor-alpha, and neutrophil adhesion molecule expression during experimental extracorporeal circulation

Clomethiazole (CMZ), a neuroprotective drug, has antiinflammatory actions. We investigated the effects of CMZ administration on plasma concentrations of interleukin (IL)-6, IL-8, IL-1beta, tumor necrosis factor-alpha, and neutrophil adhesion molecule expression during experimental extracorporeal circulation. Five healthy volunteers each donated 500 mL of blood, which was subsequently divided into equal portions. Identical extracorporeal circuits were simultaneously primed with donated blood (250 mL) and circulated for 2 h at 37 degrees C. CMZ was added to 1 of the circuits of each pair to achieve a total plasma concentration of 40 micro mol/L. Blood samples were withdrawn at (i) donation, (ii) immediately after addition of CMZ, and at (iii) 30, 60, 90, and 120 min after commencing circulation. Plasma concentrations of IL-6, IL-8, and tumor necrosis factor-alpha were less in the CMZ group compared with control after 60 min of circulation (2.2 [0.3] versus 3.2 [0.4], 14.9 [4.8] versus 21.9 [18.4], 63.3 [43.5] versus 132.2 [118.9] pg/mL, respectively, P < 0.05). After 120 min of circulation, neutrophils from CMZ-treated circuits showed significantly less CD18 expression compared with control (237.5 [97.4] versus 280.5 [111.5], P = 0.03). The addition of CMZ to experimental extracorporeal circuits decreases the inflammatory response. This effect may be of clinical benefit by decreasing inflammatory-mediated neurological injury during cardiopulmonary bypass.

IMPLICATIONS

Enhancement of gamma-aminobutyric acid(A)-mediated effects by clomethiazole (CMZ) and associated neuroprotection has been established in animal models of cerebral ischemia. In an ex vivo study, we demonstrated antiinflammatory activity of CMZ in experimental extracorporeal circulation. This represents a potential neuroprotective mechanism of CMZ in patients undergoing coronary artery bypass surgery.

How well tolerated are lipid-lowering drugs?

It has been clearly established that lipid-lowering treatments [such as 3-hydroxyl-3-methylglutamyl coenzyme A reductase inhibitors ('statins') or fibrates] can reduce cardiovascular events, and with one of the statins even total mortality, in high-risk populations. Intervention studies have not included the very old, but it is generally assumed that this patient group would benefit from these treatments to an extent similar to younger patients. Worries about the associations seen in observational studies between low cholesterol levels and cancer, cerebral haemorrhage or mood and behaviour change have been largely overcome by findings from the latest large drug intervention trials, which do not show any increase in these conditions with statin or fibrate treatments. The common adverse effects associated with these drugs are relatively mild and often transient in nature. Potentially more serious adverse effects, which are more clearly related to drug treatment and are probably dose-dependent, include elevations in hepatic transaminase levels and myopathy; however, these effects are uncommon and generally resolve rapidly when treatment is stopped. The risk of myopathy with fibrate treatment is increased in patients with renal impairment, and the risk of myopathy with statin treatment increases with co-administration of drugs that inhibit statin metabolism or transport. Other adverse effects are related to specific drugs, for example, clofibrate is associated with an increased risk of gallstones. Studies in elderly patients have not shown an increased risk of adverse effects with lipid-lowering drugs compared with younger patients, but in clinical practice there may be some increased risk, particularly with regards to drug interactions. Therefore, lipid-lowering drugs should be administered with extra caution to elderly patients.

Adolescents' perceptions of their parents' academic expectations: comparison of American, Chinese-American, and Chinese high school students

Cultural background not only influences family beliefs about the value of education, but may affect how academic expectations are communicated by parents and perceived by their children. This study examined differences in willingness to conform to parents' expectations of academic achievement as perceived by American, Chinese-American, and Chinese high school students. Findings indicated that Chinese students were more willing to accept their parents' advice and cared more about fulfilling academic expectations than did American students. Students in all three groups had similar feelings of independence. The views of Chinese-American students reflected the influence of both their Chinese heritage and the American culture in which they resided.

Differences between learning disability subtypes classified using the revised Woodcock-Johnson Psycho-Educational Battery

This study examined the characteristics of students with specific learning disabilities in either reading and spelling or arithmetic. Based on scores obtained using the revised Woodcock-Johnson Psycho-Educational Battery, students with a marked weakness in arithmetic relative to reading and spelling were designated as Group A. Group R-S showed the opposite pattern. Each group included 30 participants ranging in age from 7 to 16 years, with a mean age of 10 years. The boy-to-girl ratios were 16:14 and 19:11 in Group A and Group R-S, respectively. Comparisons using measures from the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) indicated that Group A was weaker in nonverbal skills than Group R-S, despite equivalent overall IQ scores between the two groups. Group R-S showed a within-group strength in nonverbal versus verbal skills. Group A students were more likely than Group R-S students to have counseling provided as part of their Individualized Education Program, suggesting greater socioemotional difficulty among Group A students. The present study supports the connection between nonverbal skills and socioemotional functioning noted by previous researchers, and generalizes findings from earlier studies to more current test editions.

Studies on the mutagenicity of mild gasification products of coal and their subfractions by the Salmonella/microsomal assay

Mild gasification of coal is a technology being developed in the United States in order to upgrade lower rank coals and facilitate their use in coal-burning electric generation plants. Thirteen coal-derived mild gasification products from different coal sources and processing conditions have been examined for their potential biohazards. The mutagenicity of these samples was tested with the Ames Salmonella/microsomal assay. Two solvents, dimethyl sulfoxide (DMSO) and polyoxyethylene-sorbitan monooleate (Tween 80), were used to dissolve samples in a manner to facilitate their interaction with the test organisms. The results showed that 9 of the 13 samples displayed mutagenic activity in test strains TA98 and/or TA100 with or without metabolic activation, whether dissolved in Tween 80 or DMSO. Five mutagenic and two nonmutagenic samples were class-fractionated into basic, acidic, nonpolar, and polar neutral subfractions to examine their class-related mutagenic activities. Results of the testing of subfractions of the five mutagenic and one nonmutagenic samples showed mutagenic activity in at least the nonpolar neutral fraction. The subfractions of the another nonmutagenic sample did not display any mutagenic activity. Chemical characterization of the subfractions revealed the existence of aromatic hydrocarbons in certain subfractions, which may be responsible for the mutagenic activity of the coal-derived mild gasification products.

Mutagenicity of mild gasification products in Salmonella typhimurium

Mild gasification is a coal-conversion technology that is currently under development in order to help meet future energy needs. 7 products from this process were assayed for mutagenic activity in the pre-incubation variant of the Salmonella assay (Ames test) using both DMSO and Tween 80 as sample solvents. Significant mutagenic activity was detected only in the wide-boiling-point composite materials, and the amount of this activity was found to be dependent on the solvent utilized. The highest number of revertants detected were on TA98 and its O-acetyltransferase over-producing derivative, YG1024, in the presence of the S9 microsomal fraction. Aromatic amines were suggested as a possible source of the mutagenic activity elicited. An examination of the liquid and tar phases of one composite material (MG-120) indicated that the mutagenic activity was restricted to the tar phase.

Energetics of folding subtilisin BPN'

Subtilisin is an unusual example of a monomeric protein with a substantial kinetic barrier to folding and unfolding. Here we document for the first time the in vitro folding of the mature form of subtilisin. Subtilisin was modified by site-directed mutagenesis to be proteolytically inactive, allowing the impediments to folding to be systematically examined. First, the thermodynamics and kinetics of calcium binding to the high-affinity calcium A-site have been measured by microcalorimetry and fluorescence spectroscopy. Binding is an enthalpically driven process with an association constant (Ka) equal to 7 x 10(6) M-1. Furthermore, the kinetic barrier to calcium removal from the A-site (23 kcal/mol) is substantially larger than the standard free energy of binding (9.3 kcal/mol). The kinetics of calcium dissociation from subtilisin (e.g., in excess EDTA) are accordingly very slow (t1/2 = 1.3 h at 25 degrees C). Second, to measure the kinetics of subtilisin folding independent of calcium binding, the high-affinity calcium binding site was deleted from the protein. At low ionic strength (I = 0.01) refolding of this mutant requires several days. The folding rate is accelerated almost 100-fold by a 10-fold increase in ionic strength, indicating that part of the free energy of activation may be electrostatic. At relatively high ionic strength (I = 0.5) refolding of the mutant subtilisin is complete in less than 1 h at 25 degrees C. We suggest that part of the electrostatic contribution to the activation free energy for folding subtilisin is related to the highly charged region of the protein comprising the weak ion binding site (site B).(ABSTRACT TRUNCATED AT 250 WORDS)