Nanoparticle targeting of neutrophil glycolysis prevents lung ischemia-reperfusion injury

Neutrophils exacerbate pulmonary ischemia-reperfusion injury (IRI) resulting in poor short and long-term outcomes for lung transplant recipients. Glycolysis powers neutrophil activation, but it remains unclear if neutrophil-specific targeting of this pathway will inhibit IRI. Lipid nanoparticles containing the glycolysis flux inhibitor 2-deoxyglucose (2-DG) were conjugated to neutrophil-specific Ly6G antibodies (NP-Ly6G[2-DG]). Intravenously administered NP-Ly6G(2-DG) to mice exhibited high specificity for circulating neutrophils. NP-Ly6G(2-DG)-treated neutrophils were unable to adapt to hypoglycemic conditions of the lung airspace environment as evident by the loss of demand-induced glycolysis, reductions in glycogen and ATP content, and an increased vulnerability to apoptosis. NP-Ly6G(2-DG) treatment inhibited pulmonary IRI following hilar occlusion and orthotopic lung transplantation. IRI protection was associated with less airspace neutrophil extracellular trap generation, reduced intragraft neutrophilia, and enhanced alveolar macrophage efferocytotic clearance of neutrophils. Collectively, our data show that pharmacologically targeting glycolysis in neutrophils inhibits their activation and survival leading to reduced pulmonary IRI.

B cells mediate lung ischemia/reperfusion injury by recruiting classical monocytes via synergistic B cell receptor/TLR4 signaling

Ischemia/reperfusion injury-mediated (IRI-mediated) primary graft dysfunction (PGD) adversely affects both short- and long-term outcomes after lung transplantation, a procedure that remains the only treatment option for patients suffering from end-stage respiratory failure. While B cells are known to regulate adaptive immune responses, their role in lung IRI is not well understood. Here, we demonstrated by intravital imaging that B cells are rapidly recruited to injured lungs, where they extravasate into the parenchyma. Using hilar clamping and transplant models, we observed that lung-infiltrating B cells produce the monocyte chemokine CCL7 in a TLR4-TRIF-dependent fashion, a critical step contributing to classical monocyte (CM) recruitment and subsequent neutrophil extravasation, resulting in worse lung function. We found that synergistic BCR-TLR4 activation on B cells is required for the recruitment of CMs to the injured lung. Finally, we corroborated our findings in reperfused human lungs, in which we observed a correlation between B cell infiltration and CM recruitment after transplantation. This study describes a role for B cells as critical orchestrators of lung IRI. As B cells can be depleted with currently available agents, our study provides a rationale for clinical trials investigating B cell-targeting therapies.

Reprogramming alveolar macrophage responses to TGF-β reveals CCR2+ monocyte activity that promotes bronchiolitis obliterans syndrome

Bronchiolitis obliterans syndrome (BOS) is a major impediment to lung transplant survival and is generally resistant to medical therapy. Extracorporeal photophoresis (ECP) is an immunomodulatory therapy that shows promise in stabilizing BOS patients, but its mechanisms of action are unclear. In a mouse lung transplant model, we show that ECP blunts alloimmune responses and inhibits BOS through lowering airway TGF-β bioavailability without altering its expression. Surprisingly, ECP-treated leukocytes were primarily engulfed by alveolar macrophages (AMs), which were reprogrammed to become less responsive to TGF-β and reduce TGF-β bioavailability through secretion of the TGF-β antagonist decorin. In untreated recipients, high airway TGF-β activity stimulated AMs to express CCL2, leading to CCR2+ monocyte-driven BOS development. Moreover, we found TGF-β receptor 2-dependent differentiation of CCR2+ monocytes was required for the generation of monocyte-derived AMs, which in turn promoted BOS by expanding tissue-resident memory CD8+ T cells that inflicted airway injury through Blimp-1-mediated granzyme B expression. Thus, through studying the effects of ECP, we have identified an AM functional plasticity that controls a TGF-β-dependent network that couples CCR2+ monocyte recruitment and differentiation to alloimmunity and BOS.

The role of neutrophil extracellular traps in acute lung injury

Acute lung injury (ALI) is a heterogeneous inflammatory condition associated with high morbidity and mortality. Neutrophils play a key role in the development of different forms of ALI, and the release of neutrophil extracellular traps (NETs) is emerging as a common pathogenic mechanism. NETs are essential in controlling pathogens, and their defective release or increased degradation leads to a higher risk of infection. However, NETs also contain several pro-inflammatory and cytotoxic molecules than can exacerbate thromboinflammation and lung tissue injury. To reduce NET-mediated lung damage and inflammation, DNase is frequently used in preclinical models of ALI due to its capability of digesting NET DNA scaffold. Moreover, recent advances in neutrophil biology led to the development of selective NET inhibitors, which also appear to reduce ALI in experimental models. Here we provide an overview of the role of NETs in different forms of ALI discussing existing gaps in our knowledge and novel therapeutic approaches to modulate their impact on lung injury.

Galuminox: Preclinical validation of a novel PET tracer for non-invasive imaging of oxidative stress in vivo

Overproduction of reactive oxygen species (ROS) is a well-established indicator of ongoing tissue inflammation. However, there is a scarcity of molecular imaging probes capable of providing noninvasive sensitive detection of ROS for allowing longitudinal studies of disease pathology and/or monitoring therapeutic efficacy of ROS scavengers. Herein, we report synthesis and chemical characterization of a novel metalloprobe, Galuminox, a moderately fluorescent agent that detects superoxide and hydrogen peroxide generation. Using live-cell fluorescence imaging analysis, Galuminox demonstrates ability to detect superoxide and monitor effects of ROS-attenuating agents, such as Carvedilol, Dexrazoxane, and mitoTempo in lung epithelial A549 cells. Furthermore, LPS stimulation of A549 cells that either express the mitochondria targeted fluorescent protein Keima or are stained with MitoSOX, a mitochondria-specific superoxide probe, indicates preferential co-localization of Galuminox with mitochondria producing elevated amounts of superoxide. Dynamic PET/CT scans 45 min post tail-vein administration of ⁶⁸Ga-Galuminox show 4-fold higher uptake and stable retention in lungs of LPS treated mice compared to their saline-only treated counterparts. Post preclinical PET imaging, quantitative biodistribution studies also correlate with 4-fold higher retention of the radiotracer in lungs of LPS treated mice compared with their saline-only treated control counterparts. Consistent with these observations, lung cells isolated from LPS-treated mice demonstrated elevated ROS production deploying CellROX, the ROS probe. Finally, Galuminox uptake correlates with histological and physiological evidence of acute lung injury as evident by polynuclear infiltration, thickening of the alveolar epithelial membranes and increased bronchioalveolar lavage protein content. Taken collectively, these data indicate that ⁶⁸Ga-Galuminox tracer uptake is a measure of ROS activity in acutely injured lungs and suggests its potential utility in monitoring oxidative stress in other diseases.

C3 expression by lung transplants reduces alloimmune-mediated injury

Allograft injury is a major risk factor for death in lung transplant recipients. Complement protein C3 is primarily synthesized in the liver. However, a recent study by our group has demonstrated that C3 present in pulmonary epithelial cells can be augmented to facilitate their own ability to withstand acute environmental stress. Here, we hypothesized that pulmonary C3 expression reduces the severity of allograft rejection. To address this question, C3−/−left lungs [on a C57BL/6 (B6) background] were orthotopically transplanted into wildtype (WT) fully MHC mismatched (CBA/J) recipients. The right lung, native to the recipient, served as an internal control. CBA/J lungs transplanted into C3−/− recipients, C3−/− lungs transplanted into C3−/− recipients and CBA/J lungs transplanted into WT B6 recipients were also employed as controls. One week after transplantation, recipients were euthanized and evaluated for C3 levels and graft injury. C3 protein in C3−/− recipients of WT B6 and CBA/J lungs was not detected in the peripheral circulation but was expressed within graft tissues suggesting locally expressed C3 is sequestered within the lung. Signs of graft tissue injury were only observed in allogeneic recipients. However, acute rejection severity was significantly higher in C3−/− allografts when compared to WT allografts. Additionally, C3−/− allografts had a distinct pattern of acute alveolar damage and increased cellularity not evident in WT allografts. Taken collectively, our data indicate that expression of C3 by lung allografts attenuates alloimmunedependent responses that are associated with reduced survival in humans.

Mitochondrial damage-associated molecular patterns released by lung transplants are associated with primary graft dysfunction

Primary graft dysfunction (PGD) is a major limitation in short- and long-term lung transplant survival. Recent work has shown that mitochondrial damage-associated molecular patterns (mtDAMPs) can promote solid organ injury, but whether they contribute to PGD severity remains unclear. We quantitated circulating plasma mitochondrial DNA (mtDNA) in 62 patients, before lung transplantation and shortly after arrival to the intensive care unit. Although all recipients released mtDNA, high levels were associated with severe PGD development. In a mouse orthotopic lung transplant model of PGD, we detected airway cell-free damaged mitochondria and mtDNA in the peripheral circulation. Pharmacologic inhibition or genetic deletion of formylated peptide receptor 1 (FPR1), a chemotaxis sensor for N-formylated peptides released by damaged mitochondria, inhibited graft injury. An analysis of intragraft neutrophil-trafficking patterns reveals that FPR1 enhances neutrophil transepithelial migration and retention within airways but does not control extravasation. Using donor lungs that express a mitochondria-targeted reporter protein, we also show that FPR1-mediated neutrophil trafficking is coupled with the engulfment of damaged mitochondria, which in turn triggers reactive oxygen species (ROS)-induced pulmonary edema. Therefore, our data demonstrate an association between mtDAMP release and PGD development and suggest that neutrophil trafficking and effector responses to damaged mitochondria are drivers of graft damage.

An obligatory role for club cells in preventing obliterative bronchiolitis in lung transplants

Obliterative bronchiolitis (OB) is a poorly understood airway disease characterized by the generation of fibrotic bronchiolar occlusions. In the lung transplant setting, OB is a pathological manifestation of bronchiolitis obliterans syndrome (BOS), which is a major impediment to long-term recipient survival. Club cells play a key role in bronchiolar epithelial repair, but whether they promote lung transplant tolerance through preventing OB remains unclear. We determined if OB occurs in mouse orthotopic lung transplants following conditional transgene-targeted club cell depletion. In syngeneic lung transplants club cell depletion leads to transient epithelial injury followed by rapid club cell-mediated repair. In contrast, allogeneic lung transplants develop severe OB lesions and poorly regenerate club cells despite immunosuppression treatment. Lung allograft club cell ablation also triggers the recognition of alloantigens, and pulmonary restricted self-antigens reported associated with BOS development. However, CD8+ T cell depletion restores club cell reparative responses and prevents OB. In addition, ex-vivo analysis reveals a specific role for alloantigen-primed effector CD8+ T cells in preventing club cell proliferation and maintenance. Taken together, we demonstrate a vital role for club cells in maintaining lung transplant tolerance and propose a new model to identify the underlying mechanisms of OB.

Neutrophil extracellular trap fragments stimulate innate immune responses that prevent lung transplant tolerance

Neutrophil extracellular traps (NETs) have been shown to worsen acute pulmonary injury including after lung transplantation. The breakdown of NETs by DNAse-1 can help restore lung function, but whether there is an impact on allograft tolerance remains less clear. Using intravital 2-photon microscopy, we analyzed the effects of DNAse-1 on NETs in mouse orthotopic lung allografts damaged by ischemia-reperfusion injury. Although DNAse-1 treatment rapidly degrades intragraft NETs, the consequential release of NET fragments induces prolonged interactions between infiltrating CD4⁺ T cells and donor-derived antigen presenting cells. DNAse-1 generated NET fragments also promote human alveolar macrophage inflammatory cytokine production and prime dendritic cells for alloantigen-specific CD4⁺ T cell proliferation through activating toll-like receptor (TLR) - Myeloid Differentiation Primary Response 88 (MyD88) signaling pathways. Furthermore, and in contrast to allograft recipients with a deficiency in NET generation due to a neutrophil-specific ablation of Protein Arginine Deiminase 4 (PAD4), DNAse-1 administration to wild-type recipients promotes the recognition of allo- and self-antigens and prevents immunosuppression-mediated lung allograft acceptance through a MyD88-dependent pathway. Taken together, these data show that the rapid catalytic release of NET fragments promotes innate immune responses that prevent lung transplant tolerance.

3D MRI for Quantitative Analysis of Quadrant Percent Breast Density: Correlation with Quadrant Location of Breast Cancer

RATIONALE AND OBJECTIVES

Breast cancer occurs more frequently in the upper outer (UO) quadrant, but whether this higher cancer incidence is related to the greater amount of dense tissue is not known. Magnetic resonance imaging acquires three-dimensional volumetric images and is the most suitable among all breast imaging modalities for regional quantification of density. This study applied a magnetic resonance imaging-based method to measure quadrant percent density (QPD), and evaluated its association with the quadrant location of the developed breast cancer.

MATERIALS AND METHODS

A total of 126 cases with pathologically confirmed breast cancer were reviewed. Only women who had unilateral breast cancer located in a clear quadrant were selected for analysis. A total of 84 women, including 47 Asian women and 37 western women, were included. An established computer-aided method was used to segment the diseased breast and the contralateral normal breast, and to separate the dense and fatty tissues. Then, a breast was further separated into four quadrants using the nipple and the centroid as anatomic landmarks. The tumor was segmented using a computer-aided method to determine its quadrant location. The distribution of cancer quadrant location, the quadrant with the highest QPD, and the proportion of cancers occurring in the highest QPD were analyzed.

RESULTS

The highest incidence of cancer occurred in the UO quadrant (36 out of 84, 42.9%). The highest QPD was also noted most frequently in the UO quadrant (31 out of 84, 36.9%). When correlating the highest QPD with the quadrant location of breast cancer, only 17 women out of 84 (20.2%) had breast cancer occurring in the quadrant with the highest QPD.

CONCLUSIONS

The results showed that the development of breast cancer in a specific quadrant could not be explained by the density in that quadrant, and further studies are needed to find the biological reasons accounting for the higher breast cancer incidence in the UO quadrant.

Achievement of linear response for competitive bioaffinity assays of ligands: criteria of optimized interaction systems

For a linear response, an optimized competitive bioaffinity assay of a ligand requiresC_RT> 3 ×C_PT,C_PT> 50 ×K_dR, andK_dR> 260 ×K_dX(C_RTandC_PTare concentrations of the probe and protein whileK_dXandK_dRareK_dfor the ligand and probe, respectively).

Genetic polymorphisms and tissue expression of interleukin-22 associated with risk and therapeutic response of gastric mucosa-associated lymphoid tissue lymphoma

Chronic Helicobacter pylori-stimulated immune reactions determine the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. We aimed to explore the genetic predisposition to this lymphoma and its clinical implication. A total of 68 patients and 140 unrelated controls were genotyped for 84 single-nucleotide polymorphisms in genes encoding cytokines, chemokines and related receptors that play important roles in T cell-mediated gastrointestinal immunity. Five genotypes in IL-22, namely CC at rs1179246, CC at rs2227485, AA at rs4913428, AA at rs1026788 and TT at rs7314777, were associated with disease susceptibility. The former four genotypes resided in the same linkage disequilibrium block (r(2)=0.99) that conferred an approximately threefold higher risk. In vitro experiments demonstrated that co-culturing peripheral mononuclear cells or CD4(+) T cells with H. pylori stimulated the secretion of interleukin-22 (IL-22), and that IL-22 induced the expression of antimicrobial proteins, RegIIIα and lipocalin-2, in gastric epithelial cells. Furthermore, patients with gastric tissue expressing IL-22 were more likely to respond to H. pylori eradication (14/22 vs 4/19, P<0.006). We conclude that susceptibility of gastric MALT lymphoma is influenced by genetic polymorphisms in IL-22, the product of which is involved in mucosal immunity against H. pylori and associated with tumor response to H. pylori eradication.

Facile quantitative comparison of specific activities of fusion-tagged enzyme/mutants in cell lysates via prediction of their maximum adsorption by anti-tag antibody immobilized in microplate wells

Maximum activities of 6His-tagged enzyme/mutants from lysates adsorbed on immobilized anti-tag antibody were predicted as specific activities for comparison.

The actin cytoskeleton is a suppressor of the endogenous skewing behaviour of Arabidopsis primary roots in microgravity

Before plants can be effectively utilised as a component of enclosed life-support systems for space exploration, it is important to understand the molecular mechanisms by which they develop in microgravity. Using the Biological Research in Canisters (BRIC) hardware on board the second to the last flight of the Space Shuttle Discovery (STS-131 mission), we studied how microgravity impacts root growth in Arabidopsis thaliana. Ground-based studies showed that the actin cytoskeleton negatively regulates root gravity responses on Earth, leading us to hypothesise that actin might also be an important modulator of root growth behaviour in space. We investigated how microgravity impacted root growth of wild type (ecotype Columbia) and a mutant (act2-3) disrupted in a root-expressed vegetative actin isoform (ACTIN2). Roots of etiolated wild-type and act2-3 seedlings grown in space skewed vigorously toward the left, which was unexpected given the reduced directional cue provided by gravity. The left-handed directional root growth in space was more pronounced in act2-3 mutants than wild type. To quantify differences in root orientation of these two genotypes in space, we developed an algorithm where single root images were converted into binary images using computational edge detection methods. Binary images were processed with Fast Fourier Transformation (FFT), and histogram and entropy were used to determine spectral distribution, such that high entropy values corresponded to roots that deviated more strongly from linear orientation whereas low entropy values represented straight roots. We found that act2-3 roots had a statistically stronger skewing/coiling response than wild-type roots, but such differences were not apparent on Earth. Ultrastructural studies revealed that newly developed cell walls of space-grown act2-3 roots were more severely disrupted compared to space-grown wild type, and ground control wild-type and act2-3 roots. Collectively, our results provide evidence that, like root gravity responses on Earth, endogenous directional growth patterns of roots in microgravity are suppressed by the actin cytoskeleton. Modulation of root growth in space by actin could be facilitated in part through its impact on cell wall architecture.

Effect of fibrin polymerzation on flow properties of coagulating blood

The evolution of stress in coagulating blood is described by aMaxwell-like constitutive model. The evolution is essentiallyaffected by conversion of fibrinogen to fibrin monomer, fibrinpolymerization and its crosslinking. The modifying effects of theprocess result from the active constituents of blood plasma,blood cell concentration and intensity of flow. Interrelationof stress evolution and the kinetics of polymerization species these effects in terms of the order of the kinetics ofpolymerization and degree of fibrin polymerization and values of the constitutive coefficients. The results are presented for a normal blood, averaging the effect of blood constituents and blood platelets on coagulation.

Interferon-stimulated gene ISG12b2 is localized to the inner mitochondrial membrane and mediates virus-induced cell death

Interferons (IFNs) are crucial for host defence against viruses. Many IFN-stimulated genes (ISGs) induced by viral infection exert antiviral effects. Microarray analysis of gene expression induced in liver tissues of mice on dengue virus (DENV) infection has led to identification of the ISG gene ISG12b2. ISG12b2 is also dramatically induced on DENV infection of Hepa 1-6 cells (mouse hepatoma cell line). Here, we performed biochemical and functional analyses of ISG12b2. We demonstrate that ISG12b2 is an inner mitochondrial membrane (IMM) protein containing a cleavable mitochondrial targeting sequence and multiple transmembrane segments. Overexpression of ISG12b2 in Hepa 1-6 induced release of cytochrome c from mitochondria, disruption of the mitochondrial membrane potential, and activation of caspase-9, caspase-3, and caspase-8. Treatment of ISG12b2-overexpressing Hepa 1-6 with inhibitors of pan-caspase, caspase-9, or caspase-3, but not caspase-8, reduced apoptotic cell death, suggesting that ISG12b2 activates the intrinsic apoptotic pathway. Of particular interest, we further demonstrated that ISG12b2 formed oligomers, and that ISG12b2 was able to mediate apoptosis through both Bax/Bak-dependent and Bax/Bak-independent pathways. Our study demonstrates that the ISG12b2 is a novel IMM protein induced by IFNs and regulates mitochondria-mediated apoptosis during viral infection.

Review of water reuse practices and development in China

The paper reviews existing urban water reuse schemes in north China including existing policies, institutional, technical and financial practices, summarises the data of nine water reclamation plants in six case study cities, highlights key issues and constraints, and presents development trend in water reuse sector. It is based on an intensive study programme financed by the World Bank in 2004/2005.

Assay of serum arylesterase activity by fitting to the reaction curve with an integrated rate equation

BACKGROUND

Conventional enzyme activities make use of the initial reaction rate at high substrate concentrations. Because this is not always practical, alternative enzyme assays have been sought.

METHODS

Reaction curve fitting with an integrated rate equation was investigated to assay serum arylesterase (ArE) activity using phenyl acetate (PA) and p-nitrophenol acetate (PNPA) as substrates. At a much lower initial concentration of substrate (S(0)), the simplified integrated rate equation for the ArE reaction was ln(S(0)/S(i))=(V(m)/K(m)+K(d))t(i). Treating S(0) as a parameter, the enzyme activity as V(m)/K(m) was estimated through nonlinear least square fitting to reaction curve, and the multiplication of V(m)/K(m) by K(m) produced V(m). Spontaneous hydrolysis of the substrate with a rate constant, K(d), served as the background for the estimation of V(m)/K(m).

RESULTS

Substrate concentration at 8% of K(m) was well suited for the estimation of V(m)/K(m). With either substrate, the V(m)/K(m) showed a close relation to the percentage of substrate consumed, and was not affected by common systematic errors. With either substrate, the between-run precision for V(m)/K(m) was 6% (n>7), V(m)/K(m) was proportional to the amount of ArE and closely correlated with its initial rate. The upper limit of linearity by this integrated method was much higher than the initial rate method, while the detection limit was comparable. By using either V(m)/K(m) or the initial rate, there was negligible interference with ArE activity assay from triglycerides, bilirubin, and hemoglobin.

CONCLUSIONS

These results indicate the feasibility of the integrated method for routine assay of serum enzyme activity.

In vitro-inhibition of shear-induced platelet aggregation by verapamil

The purpose of the study was to investigate the effect of verapamil on shear induced platelet aggregation (SIPA). Blood of New Zealand rabbit was collected to prepare platelet-rich-plasma (PRP) by routine centrifugation. A cone-plate shear device was employed to generate shear stress. The verapamil-treated PRP or control PRP were sheared at 37 degrees C for 120 sec. SIPA was determined from counting of free platelet. The inhibition rates of SIPA by verapamil for five doses at three shear levels were calculated accordingly. The concentration of half inhibition (IC50) was 0.03, 0.07 and 0.09 mmol/l for 20, 40 and 52 dyn/cm2, respectively. The regression for IC50 of verapamil and shear stress follows the linear equation: IC50=-0.0071+0.0019tau (r=0.999,P=0.03). The results indicate that calcium antagonist may have the potential for inhibition of SIPA although the current IC50 for rabbit platelet is higher than that of human routine blood concentration of verapamil.

Herbs of activating blood circulation to remove blood stasis

Drugs with the efficacy of modifying rheological properties of blood, blood vessels and their interactions are denoted by "hemorheologicals". Drugs of anti-hyperviscosemia, anti-coagulants, anti-platelet drugs, anti-thrombotics, vasodilators, endothelial cell protectors and anti-arthrosclerosis should be considered as hemorheologicals due to the actions in keeping blood fluidity and in maintaining normal vascular functions. The studies in hemorheology indicate that a tendency of hyperviscosity, hypercoagulation and being prone to thrombosis is prevalent in the elderly. Hemorheologicals are importance for and aging and life-threatening diseases. Blood stasis syndrome is a common pathological syndrome in the elderly. In traditional Chinese medicine, the treatment for the syndrome is by herbs which activates blood circulation to remove blood stasis. The herbs have the efficacy of improving hemorheological events. Therefore, the herbs are the source for developing hemorheologicals. Ligustrazine isolated from Chuangxiong is an example. It showed significant inhibition on shear induced platelet aggregation and on platelet intracellular calcium demonstrated by laser confocal microscope.

[The HVR genotypes and their relationship with the resistance of methicillin-resistant staphylococci]

OBJECTIVE

To investigate the HVR-PCR genotype of methicillin-resistant Staphylococci in local hospitals and compare it with the antibiograms, with aview to selecting effective antibacterial agents, moreover, to discuss preliminarily its role in molecular epidemiology.

METHODS

The minimal inhibitory concentrations(MICs) of 86 MRSA, 10 MRSE(Mc'S. epidemidis), 5 MSSE(Mc'S. epidemidis), 8 MRSH(Mc'S. haemolyticus) and 5 MSSH(Mc'S. haemolyticus) clinical isolates collected from 4 local hospitals were tested by serial two-fold agar dilution method; their DNA were extracted by moved basic lytic method, whose polymerase chain reaction(PCR) products amplified, based on the size of mec-associated hypervariable region(HVR) were analyzed by PAG vertical and agarose gel electrophoresis.

RESULTS

MRSA, MRSE and MRSH were grouped into 4, 3 and 2 HVR genotypes respectively according to the size of the PCR products. The PCR products amplified from 9 of 10 MRSE isolates were the same as the products amplified from MRSA isolates. MRSA strains in this study were mainly HVR genotypes A and D, which accounted for 52.32% and 39.53%; Genotypes B and C were the most multi-drug resistant, but genotype D was multi-sensitive. The I genotype of MRSE was multi-drug resistant, but its genotype III was multi-drug sensitive. The genotype a of MRSH was more resistant than genotype b.

CONCLUSION

These results suggest that HVR-PCR genotype method is an easy and fast method for epidemiological investigation of nosocomial infections caused by MRSA, and it is helpful for clinical selection of antibacterial agents. This method can compare the mec determinants of MRSA and Mc'CNSt isolates and hence to search for the origin of the mec determinant.

Monoclonal antibody strategies to block angiogenesis

Antibodies represent a unique class of therapeutics because of their high specificity towards a defined target antigen. Recent clinical success with antibody-based cancer therapeutics has led to an increase in the clinical development of these agents. Antibody therapeutics offer a promising approach for inhibiting new blood vessel formation (angiogenesis), which is associated with a variety of diseases, including cancer. In this review we will focus on angiogenesis-related mechanisms targeted by antibody-based therapeutics, with an emphasis on those studies where pre-clinical in vivo data is available.

Monoclonal antibodies directed to different regions of vascular endothelial cadherin extracellular domain affect adhesion and clustering of the protein and modulate endothelial permeability

Vascular endothelial cadherin (VE-cadherin) is an endothelial cell-specific cadherin that plays an important role in the control of vascular organization. Blocking VE-cadherin antibodies strongly inhibit angiogenesis, and inactivation of VE-cadherin gene causes embryonic lethality due to a lack of correct organization and remodeling of the vasculature. Hence, inhibitors of VE-cadherin adhesive properties may constitute a tool to prevent tumor neovascularization. In this paper, we tested different monoclonal antibodies (mAbs) directed to human VE-cadherin ectodomain for their functional activity. Three mAbs (Cad 5, BV6, BV9) were able to increase paracellular permeability, inhibit VE-cadherin reorganization, and block angiogenesis in vitro. These mAbs could also induce endothelial cell apoptosis in vitro. Two additional mAbs, TEA 1.31 and Hec 1.2, had an intermediate or undetectable activity, respectively, in these assays. Epitope mapping studies show that BV6, BV9, TEA 1.31, and Hec 1.2 bound to a recombinant fragment spanning the extracellular juxtamembrane domains EC3 through EC4. In contrast, Cad 5 bound to the aminoterminal domain EC1. By peptide scanning analysis and competition experiments, we defined the sequences TIDLRY located on EC3 and KVFRVDAETGDVFAI on EC1 as the binding domain of BV6 and Cad 5, respectively. Overall, these results support the concept that VE-cadherin plays a relevant role on human endothelial cell properties. Antibodies directed to the extracellular domains EC1 but also EC3-EC4 affect VE-cadherin adhesion and clustering and alter endothelial cell permeability, apoptosis, and vascular structure formation.

[Observation on the changes in nasopharyngeal carcinoma patients' olfactory before and after radiotherapy]

OBJECTIVE

Detecting nasopharyngeal carcinoma (NPC) patients' olfactory before and after radiotherapy for investigating the infection of radiotherapy on these patients' olfactory.

METHOD

100 NPC patients' olfactory were detected before the start of radiotherapy and after the termination of therapy in 3, 6, 12, 24 and 36 months.

RESULT

Patients' smell acuity decreased sharply 3 months after therapy, but varying degrees of recovery were noted in 6 and 12 months. However their smell acuity became worse in the following time.

CONCLUSION

NPC patients' smell acuity can be profoundly affected by radiotherapy. And after radiotherapy, their smell acuity will decrease wave-likely and cannot fully recover.

Monoclonal antibody to vascular endothelial-cadherin is a potent inhibitor of angiogenesis, tumor growth, and metastasis

Vascular endothelial-cadherin (VE-cad) is an endothelial cell-specific adhesion molecule that is crucial for proper assembly of vascular tubes. Here we show that a monoclonal antibody (BV13) directed to the extracellular region of VE-cad inhibits formation of adherens junctions and capillary-like structures by endothelial cells and blocks angiogenesis in the mouse cornea and in Matrigel plugs in vivo. Systemic administration of BV13 markedly decreases the growth of s.c. Lewis lung or human A431 epidermoid tumors and strongly suppresses the growth of Lewis lung metastases. These data demonstrate that VE-cad is essential for postnatal angiogenesis and thus validate VE-cad as a novel target for antiangiogenesis agents.

Inhibition by diallyl trisulfide, a garlic component, of intracellular Ca(2+) mobilization without affecting inositol-1,4, 5-trisphosphate (IP(3)) formation in activated platelets

Garlic has been used in herbal medicine for thousands of years. Some reports have shown that garlic has protective effects against atherosclerosis and inhibits platelet function. In this study, we investigated the mechanism by which diallyl trisulfide (DT), a component of garlic, inhibits platelet function. DT inhibited platelet aggregation and Ca(2+) mobilization in a concentration-dependent manner without increasing intracellular cyclic AMP and cyclic GMP. DT also had no inhibitory effects on thromboxane A(2) (TXA(2)) production in cell-free systems. Collagen-related peptide (CRP)-induced Ca(2+) mobilization is regulated by phospholipase C-gamma2 (PLC-gamma2) activation. We evaluated the effect of DT on tyrosine phosphorylation of PLC-gamma2 and the production of inositol-1,4,5-trisphosphate (IP(3)). DT at concentrations that inhibited platelet aggregation and Ca(2+) mobilization had no effects on tyrosine phosphorylation of PLC-gamma2 or on the formation of IP(3) induced by CRP. Similar results were obtained with thrombin-induced platelet activation. DT inhibited platelet aggregation and Ca(2+) mobilization induced by thrombin without affecting the production of IP(3.) We then evaluated the effect of DT on the binding of IP(3) to its receptor. DT at high concentrations partially blocked the binding of IP(3) to its receptor. Taken together, our findings suggest that the agent suppresses Ca(2+) mobilization at a step distal to IP(3) formation. DT may provide a good tool for investigating Ca(2+) mobilization.

[Skeletal dysplasia and osteoporosis due to inadequate athletic]

Athletic load is an important factor that has an influence on the growth, development and mature of skeleton. In patients who had the functional disorder of hip joint resulting from hip diseases during their teen-ages, skeletal dysplasia and osteoporosis would occur. The present paper reported 30 cases of unilateral hip disorder. The patients were 20 men and 10 women whose age ranged from 2 to 20 years. The course of disease lasted 2 to 49 years. Their primary diseases included suppurant hip arthritis (16 cases), tuberculous arthritis of hip (10 cases), and others (4 cases). The follow-up study revealed fixed hip joint in 18 cases, positive Thomas sign in 22 cases, limited motion of hip joint in 12 cases, and unequal length of lower extremities in 25 cases; at the same time X-ray films showed ankylosis of hip at normal position in 10 patients, dislocation with ankylosis of hip in 13 patients, arthritic disorder of hip in 7 patients, skeletal dysplacia of ischium and pubis in 18 patients, and skeletal dysplasia of femur in 22 patients. All patients had osteoporosis. A discussion about the basic mechanism for skeletal dysplasia and osteoporosis following inadequate athletic load is presented. We believe that the skeletal dysplasia and osteoporosis in our group were caused by the diseases that led to inadequate athletic load. Therefore it is important to provide a thorough treatment and help the patients to their strength to be loaded in time.

The effect of sheng bai solution on irradiated mice bone marrow cell division index and DNA content

Before and after general irradiation with 60Co-gamma, mice were orally given Sheng Bai Solution (SBS) for one week. SBS alleviated the irradiation-induced reduction of bone marrow cell chromosome division index. The irradiation-induced decrease of marrow DNA amount, thymic and splenic fractions, and total leukocyte number were restored to some extent. SBS also helped to ameliorate general condition of patients.

Activation of a cAMP pathway and induction of melanogenesis correlate with association of p16(INK4) and p27(KIP1) to CDKs, loss of E2F-binding activity, and premature senescence of human melanocytes

There is strong evidence that the senescent phenotype, whether induced by telomere shortening, oxidative damage, or oncogenic stimuli, is an important tumor suppressive mechanism. The melanocyte is a cell of neural crest origin that produces the pigment melanin and can develop into malignant melanomas. To understand how malignant cells escape senescence, it is first crucial to define what genes control senescence in the normal cell. Prolonged exposure to high levels of cAMP results in accumulation of melanin and terminal differentiation of human melanocytes. Here we present evidence that activation of a cAMP pathway correlates with multiple cellular changes in these cells: (1) increased expression of the transcription factor microphthalmia; (2) increased melanogenesis; (3) increased association of the cyclin-dependent kinase inhibitors (CDK-Is) p27(KIP1) and p16(INK4) with CDK2 and CDK4, respectively; (4) failure to phosphorylate the retinoblastoma protein (pRB); (5) decreased expression of E2F1, E2F2, and E2F4 proteins; (6) loss of E2F DNA-binding activity; and (7) phenotypic changes characteristic of senescent cells. Senescent melanocytes have potent E2F inhibitory activity, because extracts from these cells completely abolished E2F DNA-binding activity that was present in extracts from the early proliferative phase. We propose that increased activity of the CDK-Is p27 and p16 and loss of E2F activity in human melanocytes characterize a senescence program activated by the cAMP pathway. Disruption of cAMP-mediated and melanogenesis-induced senescence may cause immortalization of human melanocytes, an early step in the development of melanomas.

Transgenic mice expressing different levels of soluble platelet/endothelial cell adhesion molecule-IgG display distinct inflammatory phenotypes

Platelet/endothelial cell adhesion molecule-1 (PECAM-1, CD31), expressed on the surfaces of leukocytes and concentrated in the junctions between endothelial cells plays an important role in transendothelial migration of neutrophils and monocytes. Soluble recombinant PECAM-IgG injected i.v. into mice blocks acute leukocyte emigration by 80%. To study the role of PECAM in models of chronic inflammation, we generated transgenic mice constitutively expressing soluble full-length murine PECAM as an IgG chimera. Three founder lines expressed this transgene and constitutively secreted murine PECAM-IgG into the plasma where it was maintained at characteristic concentrations for each line. All mice had similar hematologic profiles to wild-type littermates and were healthy when maintained in the standard laboratory animal facility. Both the leukocytes and the endothelium of mice of all transgenic lines expressed the same levels of endogenous PECAM-1 as wild-type littermates. Similarly, there were no detectable differences in the expression of several other common leukocyte and endothelial cell adhesion molecules. Mice that produced moderate (10-20 microg/ml) concentrations of PECAM-IgG demonstrated a severely blunted acute inflammatory response, despite mobilizing appropriate numbers of circulating leukocytes. Surprisingly, mice that constitutively produced high (400-1,000 microg/ml) concentrations of PECAM-IgG were unresponsive to its anti-inflammatory effects. This is the first demonstration that a soluble form of a cell adhesion molecule can be stably expressed and retain efficacy in vivo over prolonged periods. This approach is applicable to many other extracellular molecules. However, the plasma concentrations of such constitutively produced inhibitors may greatly influence the resulting phenotype.

Retardation of skeletal muscle fatigue by the two phenylpropanoid glycosides: verbascoside and martynoside from Pedicularis plicata maxim

The effects of the phenylpropanoid glycosides verbascoside and martynoside from Pedicularis plicata were investigated on muscle contractility in Bufo gastrocnemius muscle electrically stimulated in vitro. The maximum amplitude and maintained time of contraction were mechanically recorded and used as indices of muscle contractility. After 30 min pretreatment of the muscle, verbascoside at 20.0 microM resisted muscle fatigue significantly while martynoside at 80.0 microM improved muscle contractility only slightly. These two glycosides resisted muscle fatigue depending on their antioxidative activities, which is in agreement with the role of reactive oxygen species (ROS) in promoting fatigue in skeletal muscle.

MIP-3alpha induces human eosinophil migration and activation of the mitogen-activated protein kinases (p42/p44 MAPK)

The CC chemokine macrophage inflammatory protein-3alpha (MIP-3alpha) is the product of recent electronic cloning efforts, however, little characterization of its spectrum of biological effects has been undertaken. Human eosinophils exhibited pertussis-toxin-sensitive migration in response to human recombinant (hr)MIP-3alpha. Messenger RNA for the MIP-3alpha receptor, CCR-6, and low levels of surface expression were demonstrated by reverse transcriptase-polymerase chain reaction and FACS analysis. Analyses of cell signaling revealed dose-dependent increases in intracellular calcium mobilization, calcium transients that were, however, greatly reduced when compared with MCP-3-induced responses. Further investigations of MIP-3alpha-induced signal transduction revealed time- and dose-dependent, partially pertussis toxin-dependent, increases in phosphorylation of the p42/p44 mitogen-activated protein kinases (MAPK) that occurred at 10- to 100-fold lower concentrations, and that were linked to a phosphoinositide 3-kinase pathway. These results suggest that MIP-3alpha can regulate multiple, parallel signal transduction pathways in eosinophils, and suggest that MAPK activation by MIP-3alpha in eosinophils is a significant signaling pathway for migration induction.

Gene expression and production of the monokine induced by IFN-gamma (MIG), IFN-inducible T cell alpha chemoattractant (I-TAC), and IFN-gamma-inducible protein-10 (IP-10) chemokines by human neutrophils

Monokine induced by IFN-gamma (MIG), IFN-inducible T cell alpha chemoattractant (I-TAC), and IFN-gamma-inducible protein of 10 kDa (IP-10) are related members of the CXC chemokine subfamily that bind to a common receptor, CXCR3, and that are produced by different cell types in response to IFN-gamma. We have recently reported that human polymorphonuclear neutrophils (PMN) have the capacity to release IP-10. Herein, we show that PMN also have the ability to produce MIG and to express I-TAC mRNA in response to IFN-gamma in combination with either TNF-alpha or LPS. While IFN-gamma, alone or in association with agonists such as fMLP, IL-8, granulocyte (G)-CSF and granulocyte-macrophage (GM)-CSF, failed to influence MIG, IP-10, and I-TAC gene expression, IFN-alpha, in combination with TNF-alpha, LPS, or IL-1beta, resulted in a considerable induction of IP-10 release by neutrophils. Furthermore, IL-10 and IL-4 significantly suppressed the expression of MIG, IP-10, and I-TAC mRNA and the extracellular production of MIG and IP-10 in neutrophils stimulated with IFN-gamma plus either LPS or TNF-alpha. Finally, supernatants harvested from stimulated PMN induced migration and rapid integrin-dependent adhesion of CXCR3-expressing lymphocytes; these activities were significantly reduced by neutralizing anti-MIG and anti-IP-10 Abs, suggesting that they were mediated by MIG and IP-10 present in the supernatants. Since MIG, IP-10, and I-TAC are potent chemoattractants for NK cells and Th1 lymphocytes, the ability of neutrophils to produce these chemokines might contribute not only to the progression and evolution of the inflammatory response, but also to the regulation of the immune response.

Chemokine receptor responses on T cells are achieved through regulation of both receptor expression and signaling

To address the issues of redundancy and specificity of chemokines and their receptors in lymphocyte biology, we investigated the expression of CC chemokine receptors CCR1, CCR2, CCR3, CCR5, CXCR3, and CXCR4 and responses to their ligands on memory and naive, CD4 and CD8 human T cells, both freshly isolated and after short term activation in vitro. Activation through CD3 for 3 days had the most dramatic effects on the expression of CXCR3, which was up-regulated and functional on all T cell populations including naive CD4 cells. In contrast, the effects of short term activation on expression of other chemokine receptors was modest, and expression of CCR2, CCR3, and CCR5 on CD4 cells was restricted to memory subsets. In general, patterns of chemotaxis in the resting cells and calcium responses in the activated cells corresponded to the patterns of receptor expression among T cell subsets. In contrast, the pattern of calcium signaling among subsets of freshly isolated cells did not show a simple correlation with receptor expression, so the propensity to produce a global rise in the intracellular calcium concentration differed among the various receptors within a given T cell subset and for an individual receptor depending on the cell where it was expressed. Our data suggest that individual chemokine receptors and their ligands function on T cells at different stages of T cell activation/differentiation, with CXCR3 of particular importance on newly activated cells, and demonstrate T cell subset-specific and activation state-specific responses to chemokines that are achieved by regulating receptor signaling as well as receptor expression.

[Effect of bushenjiannao 1 decoction on learning and memory functions and anti-fatigue ability in mice]

OBJECTIVE

To observe the anti-dementia effect of Bushenjiannao 1 decoction on mice.

METHOD

The learning and memory tests were realized with a water maze on the learning and memory impact of mice induced by scopolamine and cycloheximide. The effect of Bushenjiannao 1 decoction on the independent activity and anti-fatigue ability of mice were also investigated.

RESULT

Bushenjiannao 1 decoction used at a medium dose of 15 g crude drug/kg and a higher dose of 45 g crude drug/kg could significantly improve the learning and memory abilities of mice injected with scopolamine. Higher doses could improve these abilities of mice injected with cycloheximide, and also improve the anti-fatigue ability of mice. No significant differences were observed in the independent activity of mice between the groups.

CONCLUSION

Bushenjiannao 1 decoction helps improve the learning and memory abilities and enhance the anti-fatigue ability, but has no effect on excitability of the central nervous system.

CC-chemokine receptor 6 is expressed on diverse memory subsets of T cells and determines responsiveness to macrophage inflammatory protein 3 alpha

CC-chemokine receptor (CCR) 6 is the only known receptor for macrophage inflammatory protein (MIP)-3alpha, a CC chemokine chemotactic for lymphocytes and dendritic cells. Using anti-serum that we raised against the N-terminal residues of CCR6, we have characterized the surface expression of CCR6 on peripheral blood leukocytes and we have correlated CCR6 expression with responses to MIP-3alpha. We found that CCR6 was expressed only on memory T cells, including most alpha4beta7 memory cells and cutaneous lymphocyte-associated Ag-expressing cells, and on B cells. Accordingly, chemotaxis of T cells to MIP-3alpha was limited to memory cells. Moreover, calcium signals on T cells in response to MIP-3a were confined to CCR6-expressing cells, consistent with CCR6 being the only MIP-3alpha receptor on peripheral blood T cells. Unlike many CC chemokines, MIP-3alpha produced a calcium signal on freshly isolated T cells, and CCR6 expression was not increased by up to 5 days of treatment with IL-2 or by cross-linking CD3. Despite their surface expression of CCR6, freshly isolated B cells did not respond to MIP-3alpha. In addition to staining peripheral blood leukocytes, our anti-serum detected CCR6 on CD34+ bone marrow cell-derived dendritic cells. Our data are the first to analyze surface expression of CCR6, demonstrating receptor expression on differentiated, resting memory T cells, indicating differences in receptor signaling on T cells and B cells and suggesting that CCR6 and MIP-3alpha may play a role in the physiology of resting memory T cells and in the interactions of memory T cells, B cells, and dendritic cells.

Hyaluronan fragments synergize with interferon-gamma to induce the C-X-C chemokines mig and interferon-inducible protein-10 in mouse macrophages

Hallmarks of chronic inflammation and tissue fibrosis are increased influx of activated inflammatory cells, mediator release, and increased turnover and production of the extracellular matrix (ECM). Recent evidence has suggested that fragments of the ECM component hyaluronan play a role in chronic inflammation by inducing macrophage expression of chemokines. Interferon-gamma (IFN-gamma), an important regulator of macrophage functions, has been shown to induce the C-X-C chemokines Mig and IP-10. These chemokines affect T-cell recruitment and inhibit angiogenesis. The purpose of this investigation was to determine the effect of hyaluronan (HA) on IFN-gamma-induced Mig and IP-10 expression in mouse macrophages. We found a marked synergy between HA and IFN-gamma on Mig and IP-10 mRNA and protein expression in mouse macrophages. This was most significant with Mig, which was not induced by HA alone. The synergy was specific for HA, was not dependent on new protein synthesis, was not mediated by tumor necrosis factor-alpha, was selective for Mig and IP-10, and occurred at the level of gene transcription. These data suggest that the ECM component HA may influence chronic inflammatory states by working in concert with IFN-gamma to alter macrophage chemokine expression.

[Gastroenteric absorptive kinetic study on strychine in Jiufensan]

After P. O. Jiufensan, the rest curve of strychine in stomach and intestines of mice per kg was determined by TLC scanning. And the gastroenteric absorptive kinetic rule of strychine in rivo was studied, As a result, the strychine in stomach and intestine of mice accorded with pharmacokinetic model of one room. Also the main pharmacokinetic parameters of this preparation were examined.

[Study on the mitoxantrone carboxymethyl starch microspheres for hepatic artery chemoembolization]

In this paper, the technology for the preparation of plain carboxymethyl starch microsphere (CMS-MS) was optimized by the uniform design method with CMS-Na as carrier material and p-phthaloyl chloride as acrosslinker. The carboxymethyl starch microsphere loaded mitoxantrone (DHAQ-CMS-MS) was prepared by absorption method. Then, its morphology, size and size distribution, characteristics of drug loading, drug release in vitro, preparation for clinical application and its stability were studied. The pharmacokinetics of DHAQ-CMS-MS in rabbit was also studied. The results showed that the average diameter of the DHAQ-CMS-MS was 75.71 microns, drug loading was 13.21%, expansion ratio in water was 71.94%. The release of DHAQ in vitro from the microspheres was found to fit the model of single exponential function. The suspension prepared in this paper is not only convenient for clinical use, but also favorable for the improvement of the drug stability. The pharmacokinetic parameters obtained from the hepatic atery chemoembolization showed that the DHAQ-CMS-MS group, when compared with the solution group, exhibited a higher blood drug concentration in hepatic vein, its MRT was 1.96 times that of the solution group. As for the result of the peripheral vein, the MRT of the DHAQ-CMS-MS group was 1.95 times that of the solution group. This means that the drug when loaded in microsphere will be concentrated in its targeted site for a longer period, which is favorable for the treatment of hepatic cancer.

Contribution of the CXC chemokines IP-10 and Mig to the antitumor effects of IL-12

The mechanisms by which interleukin-12 (IL-12) exerts antitumor effects have been difficult to dissect. In this study, we examined the potential contribution of the chemokines interferon-gamma-inducible protein-10 (IP-10) and Mig to the antitumor effects of IL-12. Using an athymic mouse model, local inoculations with IL-12 consistently produced tumor size reductions associated with characteristic tumor necrosis and vascular damage. These effects were indistinguishable from those produced by IP-10 or Mig injected locally in the same tumor model. Local and systemic treatment with IL-12 was associated with expression of the interferon-gamma (IFN-gamma), IP-10, and Mig genes and proteins in the tumor. Levels of IP-10 and Mig expression in the tumor, the liver, and the kidney were inversely correlated with tumor size. Administration in vivo of neutralizing antibodies to IP-10 and Mig reduced substantially the antitumor effects of IL-12 inoculated locally into the tumors. These results support the notion that IP-10 and Mig contribute to the antitumor effects of IL-12 through their inhibitory effects on tumor vasculature.

Is low magnesium concentration a risk factor for coronary heart disease? The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Hypomagnesemia has been hypothesized to play a role in coronary heart disease (CHD), but few prospective epidemiologic studies have been conducted.

METHODS AND RESULTS

We examined the relation of serum and dietary magnesium with CHD incidence in a sample of middle-aged adults (n=13,922 free of baseline CHD) from 4 US communities. Over 4 to 7 years of follow-up, 223 men and 96 women had CHD develop. After adjustment for sociodemographic characteristics, waist/hip ratio, smoking, alcohol consumption, sports participation, use of diuretics, fibrinogen, total and high-density lipoprotein cholesterol levels, triglyceride levels, and hormone replacement therapy, the relative risk of CHD across quartiles of serum magnesium was 1.00, 0.92, 0.48, and 0.44 (P for trend=0.009) among women and 1.00, 1.32, 0.95, and 0.73 (P for trend=0.07) among men. The adjusted relative risk of CHD for the highest versus the lowest quartile of dietary magnesium was 0.69 in men (95% confidence interval 0.45 to 1.05) and 1.32 in women (0.68 to 2.55).

CONCLUSIONS

These findings suggest that low magnesium concentration may contribute to the pathogenesis of coronary atherosclerosis or acute thrombosis.

Tumor cell responses to IFNgamma affect tumorigenicity and response to IL-12 therapy and antiangiogenesis

Expression of a dominant negative mutant IFNgammaR1 in murine SCK and K1735 tumor cells rendered them relatively unresponsive to IFNgamma in vitro and more tumorigenic and less responsive to IL-12 therapy in vivo. IL-12 induced histologic evidence of ischemic damage only in IFNgamma-responsive tumors, and in vivo Matrigel vascularization assays revealed that while IFNgamma-responsive and -unresponsive tumor cells induced angiogenesis equally well, IL-12 and its downstream mediator IFNgamma only inhibited angiogenesis induced by the responsive cells. IL-12 induced angiogenesis inhibitory activity in the responsive cells, which may be attributable to production of the chemokine IP-10. Thus, IL-12 and IFNgamma inhibit tumor growth by inducing tumor cells to generate antiangiogenic activity.

Estrogen reduces neuronal generation of Alzheimer beta-amyloid peptides

Alzheimer's disease (AD) is characterized by the accumulation of cerebral plaques composed of 40- and 42-amino acid beta-amyloid (Abeta) peptides, and autosomal dominant forms of AD appear to cause disease by promoting brain Abeta accumulation. Recent studies indicate that postmenopausal estrogen replacement therapy may prevent or delay the onset of AD. Here we present evidence that physiological levels of 17beta-estradiol reduce the generation of Abeta by neuroblastoma cells and by primary cultures of rat, mouse and human embryonic cerebrocortical neurons. These results suggest a mechanism by which estrogen replacement therapy can delay or prevent AD.