The therapeutic efficacy and clinical translation of mesenchymal stem cell-derived exosomes in cardiovascular diseases

Exosomes, mainly derived from mesenchymal stem cells, provide a good reference for cardiac function repair and clinical application in cardiac and vascular diseases by regulating cardiomyocyte viability, inflammatory levels, angiogenesis, and ventricular remodeling after a heart injury. This review presents the cardioprotective efficacy of mesenchymal stem cell-originated exosomes and explores the underlying molecular mechanisms. Furthermore, we expound on several efficient approaches to transporting exosomes into the heart in clinical application and comment on the advantages and disadvantages of each method.

The Chains of Ferroptosis Interact in the Whole Progression of Atherosclerosis

Atherosclerosis (AS), a category of cardiovascular disease (CVD) that can cause other more severe disabilities, increasingly jeopardizes human health. Owing to its imperceptible and chronic symptoms, it is hard to determine the pathogenesis and precise therapeutics for AS. A novel type of programmed cell death called ferroptosis was discovered in recent years that is distinctively different from other traditional cell death pathways in morphological and biochemical aspects. Characterized by iron overload, redox disequilibrium, and accumulation of lipid hydroperoxides (L-OOH), ferroptosis influences endothelial cells, vascular smooth muscle cells (VSMCs), and macrophages, as well as inflammation, partaking in the pathology of many cardiovascular diseases such as atherosclerosis, stroke, ischemia-reperfusion injury, and heart failure. The mechanisms behind ferroptosis are so sophisticated and interwoven that many molecules involved in this procedure are unknown. This review systematically depicts the initiation and modulation of ferroptosis and summarizes the contribution of ferroptosis to AS, which may open a feasible approach for target treatment in the alleviation of AS progression.

Bone Marrow Mesenchymal Stem Cell-Derived Exosomes Alleviate Diabetic Kidney Disease in Rats by Inhibiting Apoptosis and Inflammation

BACKGROUND AND AIMS

Previous studies have confirmed the anti-inflammation effect of bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exo). We aimed to investigate the therapeutic effect of BMSC-Exo on diabetic kidney disease (DKD), as well as the underlying mechanisms.

METHODS

SD rats were induced by streptozotocin combined with a high-fat diet to establish a diabetes disease model. BMSCs-Exo were injected via tail veins at a weekly dose of 100 µg for 12 weeks. Pathological changes in the rat kidneys were evaluated using HE, Masson, and Periodic Acid-Schiff and immunohistochemical staining. TUNEL staining and western blot were used to evaluate the expression levels of apoptosis-related proteins in the rat kidney cells. The TNF-α level was detected by PCR and NF-κB (p65) by western blotting to examine the inflammatory responses in the renal tissue.

RESULTS

BMSCs-Exo significantly alleviated the renal structural damage and the distribution of apoptotic cells in diabetic rats. Furthermore, BMSCs-Exo increased the expression of pro-apoptosis protein Bax and decreased the expression of apoptosis-executing protein Cleaved Caspase 9 and Cleaved caspase 3. In addition, the transcription level of TNF-α in kidney tissue and NF-κB (p65) expression was also decreased through BMSCs-Exo treatment. Besides, the levels of glucose (GLU), creatinine (Cr), and burea nitrogen (BUN) in diabetic rats were decreased by the BMSC-Exo treatment.

CONCLUSIONS

BMSCs-Exo may alleviate diabetic kidney damage by inhibiting apoptosis and inflammation.

Monocyte-to-high-density lipoprotein ratio as a predictor for patients with Takayasu arteritis and coronary involvement: a double-center, observational study

Background

The implication of the monocyte-to-high-density lipoprotein ratio (MHR) in Takayasu arteritis (TAK) remains unclear.

Objective

We aimed to assess the predictive value of the MHR to identify coronary involvement with TAK and determine the patient prognosis.

Methods

In this retrospective study, 1,184 consecutive patients with TAK were collected and assessed, and those who were initially treated and with coronary angiography were enrolled and classified according to coronary involvement or no involvement. Binary logistic analysis was performed to assess coronary involvement risk factors. Receiver-operating characteristic analysis was used to determine the MHR value to predict coronary involvement in TAK. Major adverse cardiovascular events (MACEs) were recorded in patients with TAK and coronary involvement within a 1-year follow-up, and Kaplan-Meier survival curve analysis was conducted to compare MACEs between them stratified by the MHR.

Results

A total of 115 patients with TAK were included in this study, and 41 of them had coronary involvement. A higher MHR was found for TAK with coronary involvement than for TAK without coronary involvement (P = 0.014). Multivariate analysis showed that the MHR is an independent risk factor for coronary involvement in TAK (odds ratio: 92.718, 95% confidence interval (CI): 2.813-3056.291, P = 0.011). With the best cut-off value of 0.35, the MHR identified coronary involvement with 53.7% sensitivity and 68.9% specificity [area under the curve (AUC): 0.639, 95% CI: 0.544-0.726, P=0.010] and identified left main disease and/or three-vessel disease (LMD/3VD) with 70.6% sensitivity and 66.3% specificity (AUC: 0.704, 95% CI: 0.612-0.786, P = 0.003) in TAK. Combined with other variables, the MHR identified coronary involvement with 63.4% sensitivity and 90.5% specificity (AUC: 0.852, 95% CI: 0.773-0.911, P < 0.001), and identified LMD/3VD with 82.4% sensitivity and 78.6% specificity (AUC: 0.827, 95% CI: 0.720-0.934, P < 0.001) in TAK. A total of 39 patients with TAK and coronary involvement were followed up for 1 year, and 5 patients suffered a MACE. Those with an MHR >0.35 had a higher MACE incidence than their counterparts with an MHR ≤0.35 (χ² = 4.757, P = 0.029).

Conclusions

The MHR could be a simple, practical biomarker for identifying coronary involvement and LMD/3VD in TAK and predicting a long-term prognosis.

The cGAS-STING Pathway: A Ubiquitous Checkpoint Perturbing Myocardial Attributes

As an innate immune route of defense against microbial infringement, cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase (cGAS)- stimulator of interferon genes (STING) signaling does not simply participate in amplifying inflammatory responses via releasing type-I interferon (IFN) or enhance the expression of pro-inflammatory genes, but also interplays with multifarious pathophysiological activities, such as autophagy, apoptosis, pyroptosis, ferroptosis, and senescence in a broad repertoire of cells like endothelial cells, macrophages and cardiomyocyte. Thus, the cGAS-STING pathway is closely linked with aberrant heart morphologically and functionally via these mechanisms. The past few decades have witnessed an increased interest in the exact relationship between the activation of the cGAS-STING pathway and the initiation or development of certain cardiovascular diseases (CVD). A group of scholars has gradually investigated the perturbation of myocardium affected by the overactivation or suppression of the cGAS-STING. This review focuses on how the cGAS-STING pathway interweaves with other pathways and creates a pattern of dysfunction associated with cardiac muscle. This sets treatments targeting the cGAS-STING pathway apart from traditional therapeutics for cardiomyopathy and achieves better clinical value.

Comparison of clinical profiles and associated factors for acute myocardial infarction among young and very young patients with coronary artery disease

BACKGROUND

This study aimed to compare the profiles of young and very young patients with coronary artery disease (CAD) and explore the factors associated with acute myocardial infarction (AMI) based on age.

METHODS

Young CAD patients aged between 18 and 44 years diagnosed by angiography were enrolled retrospectively. They were divided into two groups according to age: young CAD was defined as patients aged between 36 and 44 years, and very young CAD was defined as patients aged between 18 and 35 years. Demographic and clinical characteristics of the patients were collected.

RESULTS

In total, 9286 patients were included in the final database. Most were assigned to the young CAD group (86.5%), and 1250 (13.5%) had very young CAD. Most demographic and clinical characteristics of the young and very young patients with CAD differed significantly. The proportion of patients with CAD in the total population increased with age, whereas the incidence of AMI showed a decreasing trend. A previous percutaneous coronary intervention (PCI) was negatively associated with AMI. Dyslipidemia, current smoking, and hyperhomocysteinemia were positively associated with AMI in the overall and young population with CAD.

CONCLUSIONS

The clinical profiles and factors associated with AMI in CAD patients of different ages were significantly different. Lifestyle-related factors were significantly associated with AMI in young patients with CAD.

cGAS-STING Pathway Performance in the Vulnerable Atherosclerotic Plaque

The important role of Ca2+ in pathogenic store-operated calcium entry (SOCE) is well-established. Among the proteins involved in the calcium signaling pathway, Stromal interacting molecule 1 (STIM1) is a critical endoplasmic reticulum transmembrane protein. STIM1 is activated by the depletion of calcium stores and then binds to another calcium protein, Orai1, to form a channel through which the extracellular Ca2+ can enter the cytoplasm to replenish the calcium store. Multiple studies have shown that increased STIM1 facilitates the aberrant proliferation and apoptosis of vascular smooth cells (VSMC) and macrophages which can promote the formation of rupture-prone plaque. Together with regulating the cytosolic Ca2+ concentration, STIM1 also activates STING through altered intracellular Ca2+ concentration, a critical pro-inflammatory molecule. The cGAS-STING pathway is linked with cellular proliferation and phenotypic conversion of VSMC and enhances the progression of atherosclerosis plaque. In summary, we conclude that STIM1/cGAS-STING is involved in the progression of AS and plaque vulnerability.

[Clinicopathological features of spinal solitary fibrous tumor]

Objective: To investigate the clinicopathological, molecular genetic, immunohistochemical and prognostic features of spinal solitary fibrous tumor (SFT). Methods: The clinical data of 12 cases of spinal SFT in Beijing Tsinghua Changgung Hospital, Affiliated to Tsinghua University, diagnosed from January 2015 to December 2021 were collected and reclassified. The clinical data, histopathology, immunohistochemistry and molecular genetics were analyzed. Follow-up and related literature reviews were conducted. Results: Among the 12 patients, there were 5 males and 7 females; the age ranged from 31 to 73 years, with a median age of 50.5 years. All 12 cases were primary tumors, including 4 cases diagnosed at the first time and 8 recurrent cases. Among the 12 cases, 8 were WHO grade 1, 3 were WHO grade 2, and 1 was WHO grade 3. Microscopically, the spinal SFT appeared as a spindle cell tumor, the stroma was rich in many thin-walled blood vessels with various histological features such as cell morphology and necrosis according to the different tumor grade. All (12/12) of the cases expressed vimentin and STAT6 (diffuse and strong nuclear stain), 11 cases (11/12) expressed both CD34 and bcl-2, and 7 cases (7/12) expressed CD99. Next-generation sequencing showed that 12 (12/12) of the patients had NAB2-STAT6 gene fusion. The 12 patients were followed up for 6 to 80 months. There were no recurrences or metastases in the 4 first cases after operation. Among the 8 recurrent cases, 2 of the patients relapsed and 2 died. Conclusions: Spinal SFT is rare and has a high recurrence tendency. Many aspects need to be considered in the diagnosis process. STAT6 is a relatively specific marker for the diagnosis of this tumor. Complete surgical resection is the preferred treatment while postoperative radiotherapy is recommended to reduce tumor recurrence.

[Induction of peripheral blood mononuclear cells to hepatocyte-like cells and preliminary study of cell response to injury under the effect of acetaminophen]

Objective: To establish a method for the induction of peripheral blood mononuclear cells to hepatocyte-like cells, and preliminarily investigate cell response to injury under the effect of acetaminophen (APAP). Methods: The surface marker CD45 of peripheral blood mononuclear cells wase detected cells by using flow cytometry and immunofluorescence methods. The cellular morphology of induced hepatocyte-like cells was observed under an inverted microscope. Real-time fluorescent quantitative PCR (RT-PCR) was used to detect the expression level of hepatocyte-specific genes, such as cytochrome (CY) P1A2, CYP3A4, CYP2C9, albumin (ALB), alpha-fetoprotein (AFP), and hepatocyte nuclear factor (HNF)4α mRNA. Immunofluorescence method was used to detect intracellular hepatocyte markers AFP, HNF4α, and ALB expression at the protein level. Biochemical analyzer was used to detect hepatocyte-specific secretory functions of AFP, ALB, and urea. Luciferase chemiluminescence method was used to detect the activity of key drug metabolizing enzyme CYP3A4. Colorimetric assay was used to detect the effect of the drug acetaminophen on hepatocyte-like cells, and alanine aminotransferase (ALT) was used as an indicator of liver cell injury. The statistical differences between the data were compared with t-test and rank-sum test. Results: The positive expression rate of CD45 cell surface markers isolated from peripheral blood mononuclear cells was about 98%, and hepatocyte-like cell morphology changes appeared on 15th day of induction. Compared with isolated mononuclear cells, CYP1A2, CYP3A4, CYP2C9, ALB, AFP and HNF4α mRNA was markedly elevated. The expression level of AFP, ALB and HNF4α protein were equally increased, and the secretory function of AFP, ALB and urea were enhanced. Compared with primary hepatocytes, CYP1A2, CYP2C9, AFP, HNF4α mRNA, and CYP3A4 mRNA did not decrease. The expression levels of AFP, ALB, and HNF4α proteins in the cells did not decrease, and the secretory function of AFP, ALB, and urea did not decrease. In addition, the CYP3A4 enzyme activity produced by hepatocyte-like cells was similar to that of primary hepatocytes. Compared with hepatocyte-like cells incubated without APAP, hepatocyte-like cells incubated with APAP had higher ALT level. Under the effect of APAP, the ALT level of hepatocyte-like cells was higher than isolated mononuclear cells. Conclusion: Peripheral blood mononuclear cells can be induced into hepatocyte-like cells with partial characteristics of hepatocytes, including the activity of CYP3A4, a key enzyme of hepatocyte drug metabolism. Additionally, preliminarily ALT secretory features reflect the hepatocytes injury under the effect of acetaminophen.

Role of Discoidin Domain Receptor 2 in Craniofacial Bone Regeneration

Bone loss caused by trauma, neoplasia, congenital defects, or periodontal disease is a major cause of disability and human suffering. Skeletal progenitor cell-extracellular matrix interactions are critical for bone regeneration. Discoidin domain receptor 2 (DDR2), an understudied collagen receptor, plays an important role in skeletal development. Ddr2 loss-of-function mutations in humans and mice cause severe craniofacial and skeletal defects, including altered cranial shape, dwarfing, reduced trabecular and cortical bone, alveolar bone/periodontal defects, and altered dentition. However, the role of this collagen receptor in craniofacial regeneration has not been examined. To address this, calvarial subcritical-size defects were generated in wild-type (WT) and Ddr2-deficient mice. The complete bridging seen in WT controls at 4 wk postsurgery was not observed in Ddr2-deficient mice even after 12 wk. Quantitation of defect bone area by micro-computed tomography also revealed a 50% reduction in new bone volume in Ddr2-deficient mice. Ddr2 expression during calvarial bone regeneration was measured using Ddr2-LacZ knock-in mice. Expression was restricted to periosteal surfaces of uninjured calvarial bone and, after injury, was detected in select regions of the defect site by 3 d postsurgery and expanded during the healing process. The impaired bone healing associated with Ddr2 deficiency may be related to reduced osteoprogenitor or osteoblast cell proliferation and differentiation since knockdown/knockout of Ddr2 in a mesenchymal cell line and primary calvarial osteoblast cultures reduced osteoblast differentiation while Ddr2 overexpression was stimulatory. In conclusion, Ddr2 is required for cranial bone regeneration and may be a novel target for therapy.

Endocrine and genetic factors affecting egg laying performance in chickens: a review

1. Egg-laying performance reflects the overall reproductive performance of breeding hens. The genetic traits for egg-laying performance have low or medium heritability, and, depending on the period involved, usually ranges from 0.16 to 0.64. Egg-laying in chickens is regulated by a combination of environmental, endocrine and genetic factors. 2. The main endocrine factors that regulate egg-laying are gonadotropin-releasing hormone (GnRH), prolactin (PRL), follicle-stimulating hormone (FSH) and luteinising hormone (LH). 3. In the last three decades, many studies have explored this aspect at a molecular genetic level. Recent studies identified 31 reproductive hormone-based candidate genes that were significantly associated with egg-laying performance. With the development of genome-sequencing technology, 64 new candidate genes and 108 single nucleotide polymorphisms (SNPs) related to egg-laying performance have been found using genome-wide association studies (GWAS), providing novel insights into the molecular genetic mechanisms governing egg production. At the same time, microRNAs that regulate genes responsible for egg-laying in chickens were reviewed. 4. Research on endocrinological and genetic factors affecting egg-laying performance will greatly improve the reproductive performance of chickens and promote the protection, development, and utilisation of poultry. This review summarises studies on the endocrine and genetic factors of egg-laying performance in chickens from 1972 to 2019.

The Role of Discoidin Domain Receptor 2 in Tooth Development

Collagen signaling is critical for proper bone and tooth formation. Discoidin domain receptor 2 (DDR2) is a collagen-activated tyrosine kinase receptor shown to be essential for skeletal development. Patients with loss of function mutations in DDR2 develop spondylo-meta-epiphyseal dysplasia (SMED), a rare, autosomal recessive disorder characterized by short stature, short limbs, and craniofacial anomalies. A similar phenotype was observed in Ddr2-deficient mice, which exhibit dwarfism and defective bone formation in the axial, appendicular, and cranial skeletons. However, it is not known if Ddr2 has a role in tooth formation. We first defined the expression pattern of Ddr2 during tooth formation using Ddr2-LacZ knock-in mice. Ddr2 expression was detected in the dental follicle/sac and dental papilla mesenchyme of developing teeth and in odontoblasts and the periodontal ligament (PDL) of adults. No LacZ staining was detected in wild-type littermates. This Ddr2 expression pattern suggests a potential role in the tooth and surrounding periodontium. To uncover the function of Ddr2, we used Ddr2^slie/slie mice, which contain a spontaneous 150-kb deletion in the Ddr2 locus to produce an effective null. In comparison with wild-type littermates, Ddr2^slie/slie mice displayed disproportional tooth size (decreased root/crown ratio), delayed tooth root development, widened PDL space, and interradicular alveolar bone defects. Ddr2^slie/slie mice also had abnormal collagen content associated with upregulation of periostin levels within the PDL. The delayed root formation and periodontal abnormalities may be related to defects in RUNX2-dependent differentiation of odontoblasts and osteoblasts; RUNX2-S319-P was reduced in PDLs from Ddr2^slie/slie mice, and deletion of Ddr2 in primary cell cultures from dental pulp and PDL inhibited differentiation of cells to odontoblasts or osteoblasts, respectively. Together, our studies demonstrate odontoblast- and PDL-specific expression of Ddr2 in mature and immature teeth, as well as indicate that DDR2 signaling is important for normal tooth formation and maintenance of the surrounding periodontium.

Changes and analysis of anti-HBs titres after primary immunization in 1- to 16-year-old Chinese children: A hospital-based study

Immunization with the hepatitis B vaccine is the most effective measure to prevent Hepatitis B Virus (HBV) infection. The aim of this study was to investigate the change in antibody levels induced by administration of the hepatitis B vaccine in children aged 1-16 year old in a large sample sized investigation. HBV markers were determined in 93 326 1- to 16-year-old hospitalized children who completed primary immunization as infants from south-west China, Chongqing. Analyses were performed on anti-HBs titre changes with increasing age, and the revaccination effect was evaluated in children aged 7-14. The percentage of protective antibody was between 45.29% and 63.33% in all age groups, but was higher in the 1-, 2- and 3-year-old groups (90.31%, 83.95% and 71.82%, respectively), and the rate of high-responder was 5.03%-10.56%, except in the 1-year-old group (23.33%). Additionally, 3.33%-25.79% of subjects had not seroconverted. There was no significant difference in antibody levels between girls and boys (P > .05). The Geometric Mean Titers in children with confirmed revaccination history were significantly higher than those with unknown or no revaccination history (P < .0001). In conclusion, the overall rate of protective anti-HBs was 67.10% with consecutive age groups from 1 to 16, it decreased from 90.31% to 45.29% for 1- to 8-year-old individuals, and interestingly, the rate increased from 45.46% to 63.33% for subjects aged 9-15. Anti-HBs titres were significantly improved after revaccination. Booster doses are recommended for those without seroconversion, especially children who live in school with other students or have family members with positive HBsAg.

Selective Role of Discoidin Domain Receptor 2 in Murine Temporomandibular Joint Development and Aging

Temporomandibular joint (TMJ) disorders are often associated with development of osteoarthritis-like changes in the mandibular condyle. Discoidin domain receptor 2 (DDR2), a collagen receptor preferentially activated by type I and III collagen found in the TMJ and other fibrocartilages, has been associated with TMJ degeneration, but its role in normal joint development has not been previously examined. Using Ddr2 LacZ-tagged mice and immunohistochemistry, we found that DDR2 is preferentially expressed and activated in the articular zone of TMJs but not knee joints. To assess the requirement for Ddr2 in TMJ development, studies were undertaken to compare wild-type and smallie ( slie) mice, which contain a spontaneous deletion in Ddr2 to produce an effective null allele. Analysis of TMJs from newborn Ddr2^slie/slie mice revealed a developmental delay in condyle mineralization, as measured by micro-computed tomography and histologic analysis. In marked contrast, knee joints of Ddr2^slie/slie mice were normal. Analysis of older Ddr2^slie/slie mice (3 and 10 mo) revealed that the early developmental delay led to a dramatic and progressive loss of TMJ articular integrity and osteoarthritis-like changes. Mutant condyles had a rough and flattened bone surface, accompanied by a dramatic loss of bone mineral density. Mankin scores showed significantly greater degenerative changes in the TMJs of 3- and 10-mo-old Ddr2^slie/slie mice as compared with wild-type controls. No DDR2-dependent degenerative changes were seen in knees. Analysis of primary cultures of TMJ articular chondrocytes from wild-type and Ddr2^slie/slie mice showed defects in chondrocyte maturation and mineralization in the absence of Ddr2. These studies demonstrate that DDR2 is necessary for normal TMJ condyle development and homeostasis and that these DDR2 functions are restricted to TMJ fibrocartilage and not seen in the hyaline cartilage of the knee.

Identification and characterization of a phospholipase A1 activity type three secreted protein, PP_ExoU from Pseudomonas plecoglossicida NB2011, the causative agent of visceral granulomas disease in large yellow croaker (Larimichthys crocea)

Pseudomonas plecoglossicida NB2011, the causative agent of visceral granulomas disease in farmed Larimichthys crocea in China, encodes a predicted type three effector PP_ExoU, a homolog of the cytotoxin ExoU of Pseudomonas aeruginosa. In this study, secretion of PP_ExoU was tested in various broth, the protein was expressed with the pET30a prokaryotic system, the phospholipase A (PLA) activity of the recombinant protein was determined with fluorogenic phospholipid substrates, fusion expression with green fluorescent protein in transfected HeLa cells was investigated, and the lactate dehydrogenase (LDH) level was measured. The results showed the protein was type three secreted in several media; the recombinant protein displayed significant PLA1 activity with ubiquitin. Fluorescence was observed on the cell membrane and scattered in the cytoplasm of HeLa cells expressing catalytic wild-type PP_ExoU, blebbing and stretching developed in the cell membranes indicating of membrane damage. Fluorescence scattered in the cytoplasm of cells expressing the catalytic inactive protein. A significant LDH level was detected in HeLa cells expressing wild-type PP_exoU, but not in the Ser/Asp-mutated protein, suggestion mutation of predicted catalytic residues abolished the PLA activity. This is the first report on the function of a secreted type three protein from P. plecoglossicida.

Abstract P4-03-03: Microenvironment induced DDR2 mediates stromal-cancer interactions and metastasis growth in breast cancer

This abstract was not presented at the symposium.

Hypersensitivity to ticagrelor and low response to clopidogrel: a case report

Ticagrelor is widely used to treat acute coronary syndrome. Hypersensitivity reaction of ticagrelor is rarely recognized. A low response to clopidogrel, which occurs in up to 23% of patients, is an independent risk factor for stent thrombosis. Management of patients with a low response to clopidogrel and ticagrelor hypersensitivity who are undergoing antithrombotic therapy remains to be a challenge. Herein, we report a patient with low response to clopidogrel and ticagrelor hypersensitivity, who was successfully managed using aspirin and warfarin.

ZnO nanosheet-assisted immobilization of Ag nanoparticles on graphene/Ni foam for highly efficient reduction of 4-nitrophenol

ZnO nanosheet-assisted immobilization of Ag nanoparticles on graphene/Ni foam forming a novel hybrid structure for catalysis.

Healing Cranial Defects with AdRunx2-transduced Marrow Stromal Cells

Marrow stromal cells (MSCs) include stem cells capable of forming all mesenchymal tissues, including bone. However, before MSCs can be successfully used in regeneration procedures, methods must be developed to stimulate their differentiation selectively to osteoblasts. Runx2, a bone-specific transcription factor, is known to stimulate osteoblast differentiation. In the present study, we tested the hypothesis that Runx2 gene therapy can be used to heal a critical-sized defect in mouse calvaria. Runx2-engineered MSCs displayed enhanced osteogenic potential and osteoblast-specific gene expression in vitro and in vivo. Runx2-expressing cells also dramatically enhanced the healing of critical-sized calvarial defects and increased both bone volume fraction and bone mineral density. These studies provide a novel route for enhancing osteogenesis that may have future therapeutic applications for craniofacial bone regeneration.

Unusually high soil nitrogen oxide emissions influence air quality in a high-temperature agricultural region

Fertilized soils have large potential for production of soil nitrogen oxide (NO_x=NO+NO₂), however these emissions are difficult to predict in high-temperature environments. Understanding these emissions may improve air quality modelling as NO_x contributes to formation of tropospheric ozone (O₃), a powerful air pollutant. Here we identify the environmental and management factors that regulate soil NO_x emissions in a high-temperature agricultural region of California. We also investigate whether soil NO_x emissions are capable of influencing regional air quality. We report some of the highest soil NO_x emissions ever observed. Emissions vary nonlinearly with fertilization, temperature and soil moisture. We find that a regional air chemistry model often underestimates soil NO_x emissions and NO_x at the surface and in the troposphere. Adjusting the model to match NO_x observations leads to elevated tropospheric O₃. Our results suggest management can greatly reduce soil NO_x emissions, thereby improving air quality.

Soil NO_x emissions can significantly impact air quality in agricultural regions, particularly high temperature fertilized systems. Here, the authors investigate NO_x emissions in one such system in California and suggest that the NO_x emissions are the highest ever observed, with implications for air quality.

Inactivation of internalized Salmonella Typhimurium in lettuce and green onion using ultraviolet C irradiation and chemical sanitizers

AIMS

The internalized human pathogens in fresh produce are not effectively removed during conventional washing, and therefore, it may cause foodborne illness when the produce is consumed raw. Thus, effective nonthermal processes are needed to prevent this risk.

METHODS AND RESULTS

Green fluorescence protein-tagged Salmonella Typhimurium was either sprayed on the surface of iceberg lettuce or injected into the bottom part (bulb) of green onions to induce bacterial internalization. The contaminated vegetables were collected after 2 days and subjected to surface disinfection. Different fluencies of UV-C radiation (75-900 mJ cm(-2)) and two fluencies of UV-C (450, 900 mJ cm(-2)) combined with chlorine and peracetic acid (PAA) were applied to the produce to examine the inactivation efficiency of internalized bacteria. A range of 1·96-2·52 log reduction in the internalized Salmonella was achieved when the lettuce was treated with higher UV-C fluency (150, 450, 900 mJ cm(-2)) or UV-C combined with chemical disinfectants. Significant reduction (1·00-1·49 log CFU g(-1)) in internalized Salmonella was observed in green onion treated with UV-C with the fluency of 150 or 900 mJ cm(-2) or UV-C-chlorine/PAA. No significant reduction was observed in either lettuce or green onion treatments when chlorine or PAA was used alone. The food quality measured with firmness was not changed during any treatments. However, a slight colour change was observed in lettuce only when UV-C was used at 900 mJ cm(-2).

CONCLUSION

High fluency UV-C can significantly inactivate the internalized Salmonella in lettuce and green onion while maintaining the food quality.

SIGNIFICANCE AND IMPACT OF THE STUDY

This research provides applicable research outcomes for developing nonthermal methods to inactivate internalized pathogens in fresh produce.

Ozonation as a clean technology for fresh produce industry and environment: sanitizer efficiency and wastewater quality

AIMS

Inactivating microbial contaminants in fresh produce commonly uses chlorine washing. The effectiveness of ozone was explored as an alternative to chlorine in produce washing for ensuring microbial safety while maximizing water reusability.

METHODS AND RESULTS

An ozone washing system was designed to permit continuous addition of contaminated produce and the reuse of washing water. The effectiveness of ozonation (<2 mg l(-1) ) was determined using Bacillus subtilis spores as a stricter measure of efficiency with processing time of 10 min. As a comparison, chlorine (c. 100 mg l(-1) ) was tested in parallel. Water quality characteristics, including chemical oxygen demand, total suspended solids, disinfectants concentration and microbial reduction were measured. Ozonation showed an average of 1·56 log reduction of B. subtilis spores on lettuce, while chlorination achieved a 1·30 log reduction. The effluents after ozonation demonstrated improved water quality, both in physicochemical quality and microbial quality compared to chlorination.

CONCLUSION

Aqueous ozone treatment is effective against microbial contaminants on fresh produce and enables extended use of washing water.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results provide significant data about ozone disinfection efficacy and its impact on the water reusability, which can facilitate the ozone utilization in the fresh produce production as an environmental friendly alternative.

Long-term (4-year) outcomes and predictors of adverse cardiac events after sirolimus-eluting stent implantation in unprotected left main coronary artery

The long-term safety and efficiency of sirolimus-eluting stent (SES) treatment in unprotected left main coronary artery (ULMCA) have not yet been ascertained.From 2003 to 2006, 126 consecutive patients with de novo lesions in ULMCA who underwent SES were retrospectively analyzed in a single center in China. During 4-year follow-up, major adverse cardiovascular event (MACE)-free survival was 74.6%. Cardiac death occurred in 5 (4.0%), and target lesion revascularization (TLR) and target vessel revascularization (TVR) occurred in 15 (11.9%) and 24 (19.0%) patients, respectively. One (0.8%) experienced probable stent thrombosis while 1 (0.8%) presented possible stent thrombosis. Impaired LVEF (< 40%) and high surgical risk (Euro score > 6) were the independent predictors of MACEs.PCI with SES for de novo lesions in ULMCA is feasible with a low procedural risk. However, SES was associated with a relatively higher rate of TLR and TVR. Impaired LVEF and high surgical risk were important predictors of MACEs.

Factors associated with occupational strain among Chinese teachers: a cross-sectional study

OBJECTIVES

With the reform of the education system in China, teachers are suffering from more occupational strain, which is believed to impair their working state indirectly and affect their health. This study assessed occupational strain and explored the related factors among Chinese teachers.

STUDY DESIGN

Cross-sectional with cluster sampling.

METHODS

The study population was composed of 3570 school teachers working in 64 primary and middle schools in Heping District in Shenyang, China. Data were collected using a self-administered questionnaire (the Chinese version of the Occupational Stress Inventory scale). Multivariate linear regression analyses were performed to study the factors related to occupational strain.

RESULTS

The average score on the Personal Strain Questionnaire (PSQ) for the whole study population was 106.5 (107.5 in men and 106.3 in women). Teachers with chronic disease, a greater number of days of sick leave, recent experience of a stressful life event and divorced/separated/widowed status tended to suffer greater strain than their peers. Regression analyses showed that the PSQ score was significantly associated with role overload, role boundary, responsibility and physical environment, and inversely associated with recreation and rational coping. The most crucial predictors of occupational strain were chronic disease, days of sick leave, recent experience of a stressful life event and marital status. Being a class teacher was the strongest indicator of interpersonal strain. Self-care was associated with vocational strain and psychological strain, and inversely associated with physical strain.

CONCLUSIONS

Most teachers in this study experienced a high degree of occupational strain. Chronic disease, days of sick leave, recent experience of a stressful life event and divorced/separated/widowed status played prominent roles in occupational strain. In addition, role overload, role boundary, responsibility and physical environment induce occupational strain, while recreation and rational coping have a positive effect on occupational strain. Interventions such as proper management of chronic diseases and establishment of a balanced work-family life are crucial to reduce occupational strain. Recreation and training in coping abilities are needed to enhance positive working environments and attenuate the occupational strain imposed on teachers.

Clinical prognostic significance of plasma cystatin C levels among patients with acute coronary syndrome

BACKGROUND

This article aims to investigate the changes of plasma cystatin C concentration (PcyC), and to evaluate the relationship between PcyC and acute coronary syndrome.

METHODS

A total of 126 consecutive patients with coronary artery disease (CAD) were enrolled in this study, consisting of 34 patients with stable angina pectoris (SAP), 56 patients with unstable angina pectoris (UAP), 36 patients with acute myocardial infarction (AMI), and 34 healthy subjects as controls. Plasma cystatin C, high sensitivity C-reactive protein (hs-CRP), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), and uric acid (UA) in all subjects were determined. All patients were followed up for 6 months and adverse cardiovascular events were recorded.

RESULTS

Plasma cystatin C was elevated in CAD. Cystatin C levels were significantly higher in UAP patients than those in SAP patients and controls (2013.83 +/- 633.85 ng/mL vs 1348.41 +/- 369.62 ng/mL and 1509.99 +/- 408.65 ng/mL, P < 0.05), but were much lower than those in AMI patients (2013.83 +/- 633.85 ng/mL vs 2873.55 +/- 1149.48 ng/mL, P < 0.05). Patients with AMI also exhibited significantly higher cystatin C levels than SAP patients and the control group (2873.55 +/- 1149.48 ng/mL vs 1348.41 +/- 369.62 ng/mL and 1509.99 +/- 408.65 ng/mL, P < 0.01). Much higher hs-CRP concentrations were found in UAP patients (1.58 +/- 2.81 mg/L, P < 0.05) and AMI patients (20.68 +/- 18.98 mg/L, P < 0.01). Cystatin C was positively and significantly correlated with age, hs-CRP, white blood cells (WBC), creatinine, and UA (r > 0, P < 0.05), whereas a significantly negative correlation was observed with HDL-C (r = - 0.227, P < 0.05). These coefficients were clearly high for creatinine (r = + 0.612) and WBC (r = + 0.459). During the 6 month follow-up, 26 patients were found with adverse cardiovascular events and had significantly higher cystatin C levels than the 22 control patients at admission (2356.73 +/- 897.64 ng/mL vs 1469.51 +/- 574.83 ng/mL, P < 0.01).

CONCLUSIONS

Cystatin C plays an important role in the development of CAD and PcyC is a strong predictor for risk of cardiovascular events.

Relationship between quality of life and occupational stress among teachers

OBJECTIVES

With major changes in the education system and limited resources supplied by the Government, Chinese teachers have been suffering from greater occupational stress in recent years, which is believed to affect their physical and mental health. The aim of this study was to explore the relationship between quality of life and occupational stress in primary and middle school teachers.

STUDY DESIGN

Originals.

METHODS

A cross-sectional study was conducted using cluster sampling. The study population was composed of 3570 school teachers working in 64 primary and middle schools in Heping District in Shenyang, China. A demographic questionnaire, the 36-item Short-Form Health Survey (SF-36) and the Occupational Stress Inventory Revised Edition were employed to collect demographic variables and assess quality of life and occupational stress. Multivariate stepwise linear regression analyses were performed to study the relationship between quality of life and occupational stress.

RESULTS

The mean scores for both male and female teachers in this study were significantly lower than those for the Chinese general population for all dimensions of quality of life, except mental health and vitality (P<0.05). Male teachers scored significantly higher than female teachers for physical functioning, bodily pain, vitality and physical health (P<0.05). Age, role overload, role insufficiency, vocational strain, psychological strain, physical strain, recreation and rational coping were significantly associated with both the physical and mental component summaries of the SF-36 (P<0.05). Gender, physical environment and self-care appeared to be robust indicators of physical health (P<0.05), while role insufficiency, interpersonal strain and social support were strong indicators of mental health (P<0.05).

CONCLUSIONS

In China, teachers have a lower health status than the general population. The quality of life of female teachers is worse than that of male teachers, and deteriorates with age. Occupational stress and strain induce worsening physical and mental conditions for teachers, while coping resources could promote their health. This study suggests that having adequate coping resources, especially social support, in workplaces may be an important factor for improving teachers' quality of life. Moreover, psychological interventions should be set up for teachers, and psychological counselling should be provided to relieve stress and enhance quality of life.

Spectroscopic study on the enhanced excitation of an electron cyclotron resonance nitrogen plasma by pulsed laser ablation of an aluminum target

The influence of pulsed laser ablation of an aluminum target on the nitrogen plasma produced by electron cyclotron resonance (ECR) microwave discharge has been studied by optical emission spectroscopy (OES) with time and space resolution. The continuous wave (CW) feature of the optical emissions from the ECR nitrogen plasma turns to vary with time and space due to pulsed laser ablation and the expansion of the ablation-induced aluminum plume in the nitrogen plasma. The optical emissions from the nitrogen plasma increase significantly and the emission intensity of nitrogen molecular ions is observed to be more than 20 times higher with the target being ablated in comparison to the case without target ablation. The comparison of the optical emissions from the nitrogen plasma with those from the aluminum plume indicates that the excitation enhancement of the nitrogen plasma occurs in the region where the aluminum plume is expanding, revealing that the expansion of the aluminum plume leads to the excitation enhancement of the nitrogen plasma. Relevant mechanisms responsible for the excitation enhancement of the nitrogen plasma through hybrid processes of ECR microwave discharge and pulsed laser ablation are also discussed.

A clinical investigation on garlicin injectio for treatment of unstable angina pectoris and its actions on plasma endothelin and blood sugar levels

To investigate the therapeutic effects and mechanisms of garlicin for treatment of unstable angina pectoris (UAP), garlicin injectio was intravenously dripped 60 mg/day in 34 cases for 10 days. Nitroglycerine was used in 21 cases of the control group. The results showed that the total effective rates in improving symptoms and electrocardiogram after garlicin treatment were respectively 82% and 62%, and that the plasma endothelin and blood sugar levels were markedly lowered in cases with hyperglycemia.

c-Src signaling induced by the adapters Sin and Cas is mediated by Rap1 GTPase

Oncogenic Src proteins have been extensively studied to gain insight into the signaling mechanisms of Src. To better understand signaling through wild-type Src, we used an approach that involves activation of Src signaling through the binding of physiologic ligands to the Src SH3 domain. To this end, we used full-length and truncated versions of the multiadapter molecules Cas and Sin to activate c-Src, and we examined the intracellular pathways that mediate Src signaling under these conditions. We show that although all proteins bind to and are phosphorylated by c-Src, quantitative differences exist in the ability of the different ligands to activate c-Src signaling. In addition, we show that Sin- and Cas-induced Src signaling, as assayed by transcriptional activation, is exclusively mediated through a pathway that involves the adapter Crk and the GTP-binding protein Rap1. These data are in contrast to previous observations showing Ras to mediate signaling downstream of transforming Src alleles. In our system, we found that signaling through the oncogenic SrcY527 mutant is indeed mediated by Ras. In addition, we found that Rap1 also mediates oncogenic Src signaling. Our results show for the first time that Rap1 mediates c-Src kinase signaling and reveal mechanistic differences in the signaling properties of wild-type and transforming Src proteins.

Altered expression of Gi-protein and adenylyl cyclase activity in hearts from one kidney one clip hypertensive rats: effect of captopril

OBJECTIVE

To investigate whether one kidney one clip (1K-1C) hypertensive rats associated with high levels of angiotensin II (Ang II) exhibit enhanced expression and functions of G proteins in the heart and whether the enhanced expression can be attributed to Ang II.

METHODS

The levels of G protein and G protein mRNA in hearts from 1K-1C hypertensive rats were determined by immunoblotting and Northern blotting techniques using specific antibodies and cDNA probes, respectively, for different isoforms of G proteins. Adenylyl cyclase activity, stimulated or inhibited by agonists, was determined to examine the function of G proteins.

RESULTS

The levels of Gialpha-2 and Gialpha-3 proteins and mRNA were significantly increased in hearts from 1K-1C hypertensive rats compared with control rats, whereas the levels of Gsalpha were unchanged. Guanosine 5'-[3'-thio] triphosphate (GTPgammaS), isoproterenol, glucagon, sodium fluoride (NaF) and forskolin (FSK) stimulated adenylyl cyclase activity in hearts from control and hypertensive rats to varying degrees; however, the stimulations were significantly less in hypertensive rats compared with control rats. On the other hand, the inhibitory effect of low concentrations of GTPgammaS on FSK-stimulated adenylyl cyclase activity (an index of Gi function) was significantly enhanced in hearts from 1K-1C hypertensive rats, whereas the inhibitory effect of C-ANF4-23 on adenylyl cyclase was increased and that of Ang II was decreased in hearts from 1K-1C hypertensive rats. Captopril, an angiotensin-converting enzyme inhibitor, restored the augmented levels of Gi proteins and also the altered stimulation and inhibition of adenylyl cyclase by GTPgammaS, stimulatory and inhibitory hormones, respectively, in hearts from hypertensive rats.

CONCLUSION

These data suggest that 1K-1C hypertensive rats exhibit enhanced expression of Gialpha proteins and associated functions that may be attributable to the enhanced levels of Ang II in this model of hypertension.

Stage-specific expression of alpha1,2-fucosyltransferase and alpha1, 3-fucosyltransferase (FT) during mouse embryogenesis

Lex [Galbeta1-4(Fucalpha1-3)GlcNAc] and Ley [Fucalpha1-2Galbeta1-4(Fucalpha1-3)GlcNAc] are both stage-specific embryonic antigens. Lex is first detected on the blastomeres of the 8-cell stage embryo, which correlates with the onset of blastomere compaction. Ley is highly expressed on the surface of the blastocyst, which has been shown to be involved in blastocyst attachment in the mouse. In the present study, mouse alpha1,2-FT (also known as FUT1) and alpha1,3-FT (also known as Fuc-TIV), which were responsible for Lex and Ley formation, were examined in preimplantation stage embryos by reverse transcription-PCR and in situ hybridization. alpha1,3-FT mRNA was detected in all embryos of preimplantation stage, while alpha1,2-FT mRNA emerged in the later stage embryos from 8-cell to 16-cell to the blastocyst. These results indicated the expression of Ley was regulated by alpha1,2-FT. In situ hybridization showed that these two enzyme mRNAs were detected only in morula and blastocyst stage embryos. The alpha1,2-FT and alpha1, 3-FT mRNAs were located in both the inner cell mass and the trophoblast cells. 2-Cell and 4-cell embryos were isolated from the oviduct and cultured in vitro to the 8-cell, morula and blastocyst stage. The expression of alpha1,2-FT and alpha1,3-FT were observed in these embryos developed in vitro; immunohistochemical analysis also showed that Ley expression was positive. These results suggested the stage-specific expression of Ley on the embryos was synthesized by endogenous alpha1,2-FT and alpha1,3-FT rather than transfer from other sources. In addition, the expression of alpha1, 2-FT was differentially regulated and the uterine factor was not prerequisite of the expression of Ley.

[Analysis of bone mineral density and relevant factors in 781 healthy people aged 15 to 50]

OBJECTIVE

To determine further the age to form peak bone mass (PBM) and the factor influencing it and bone mineral density (BMD) and to find an effective way to prevent from osteoporosis in the elderly.

METHODS

BMD was measured in 781 people aged 15 to 50 years and relevant factors in lifestyle were investigated. Multivariate regression was used to analyze the relationship between BMD and lifestyles and to identify both risk and benefit factors for osteoporosis.

RESULTS

For every ten-kilogram increase in body weight, BMD at varied sites increased by an amount of 0.028 - 0.056 g/cm(2) for males and 0.050 - 0.086 g/cm(2) for females, respectively. During their adolescence for males, for every increase of one grade in physical exercise, BMD at varied sites increased by an amount of 0.034 - 0.078 g/cm(2) in males and BMD at lumbar vertebra in males aged 15 - 24 correlated negatively with their total amount of alcohol drinking, and that at lumbar vertebra and of the whole body increased by about 0.035 g/cm(2) in females, which correlated negatively with their total amount of cigarette smoking. Female BMD at lumbar vertebra correlated reversely with their age of menarche and correlated positively with their average time of breast feeding.

CONCLUSION

Increase in physical exercise during puberty could increase PBM for the adolescents and keeping adequate body weight and reducing cigarette smoking and alcohol drinking would benefit for the prevention from age-related osteoporosis.

[Genetic diversity among Chinese peanut rhizobia by rep-PCR analysis]

Repetitive sequences(repetitive extragenic palindromic[REP], and enterobacterial repetitive intergenic consensus [ERIC]) with the polymerase chain reaction(PCR) were used to fingerprint pure DNA extracted from 79 bradyrhizobial strains. These strains included 59 peanut rhizobia [Bradyrhizobium sp. (Arachis)] isolated from root nodules of 24 peanut (Arachis hypogaea L) cultivars from 23 sites in 11 provinces in China, 6 peanut rhizobial strains from other nations, and 14 reference strains of other bradyrhizobia. All the strains were clustered at the level of 11%, 2%, and 11, 24 clusters were obtained at the similarity of 50% with REP-PCR and ERIC-PCR fingerprints, respectively. The results showed that significant genomic diversity exists within the peanut rhizobia from China. Also they suggested that there are different distributions of REP and ERIC in genomic DNA of the peanut rhizobia. The combined results, REP plus ERIC data, were found between the both above. The genomic diversity seems not to correlate with their host and geographic origins. Our results supported this technique is a useful tool for genotypic characterization and identification of rhizobia as well as ecological studies.

[Origin and progress of myelodysplastic syndrome with hypoplasia]

OBJECTIVE

To study the origin and progress of myelodysplastic syndrome (MDS) with hypoplasia.

METHODS

The data of twenty-five cases of hypomyeloplastic MDS diagnosed by our department in the last ten years were analyzed. 17 of the 25 cases were followed up for a long time.

RESULTS

(1) The percentage of hypomyeloplastic MDS was 11.4% of the total 219 MDS patients. The median age of the 25 cases was (44.8 +/- 14.7) years. (2) FAB subtype: There were 11 cases of RA and 14 of RAEB. (3) Hypomyeloplastic MDS seems to be a developmental phase in the clinical course in some of the patients and not a special type of MDS. Hyper- and hypo-myeloplasia could be transformed from one to another. The transformation of myelodysplasia could occur either in the same or and different FAB subtype. (4) Seven of the seventeen cases transformed to acute leukemia (41.2%), 6 cases were AML and 1 was ALL. 3 of the 7 cases transformed to hypomyeloplastic leukemia and the remaining 4 transformed to hypermyeloplastic leukemia. (5) The median time from the diagnosis of RAEB to leukemia transformation, was 27 months in 7 cases with hypoplastic RAEB. (6) No relationship was found between therapeutic medicines and development of hypomyeloplastic MDS.

CONCLUSION

It is suggested that hypomyeloplastic MDS is probably a developmental phase in the clinical course of MDS, but not a special type.

Angiotensin II enhances the expression of Gialpha in A10 cells (smooth muscle): relationship with adenylyl cyclase activity

In the present studies, we have investigated the effect of angiotensin II (AII) on guanine nucleotide regulatory protein (G protein) expression and functions in A10 smooth muscle cells. AII treatment of A10 cells enhanced the levels of inhibitory guanine nucleotide regulatory protein (Gi) as well as Gi mRNA and not of stimulatory guanine nucleotide regulatory protein (Gs) in a concentration-dependent manner as determined by immunoblot and Northern blot analysis, respectively. AII-evoked increased expression of Gialpha-2 and Gialpha-3 was inhibited by actinomycin D treatment (RNA synthesis inhibitor). The increased expression of Gialpha-2 and Gialpha-3 by AII was not reflected in functions, because the GTPgammaS-mediated inhibition of forskolin-stimulated adenylyl cyclase and the receptor-mediated inhibition of adenylyl cyclase by AII and C-ANP4-23 [des(Gln18, Ser19, Gln20, Leu21, Gly22) ANP4-23-NH2] were not augmented but attenuated in AII-treated A10 cells. The attenuation was prevented by staurosporine (a protein kinase C inhibitor) treatment. On the other hand, AII treatment did not affect the expression and functions of stimulatory guanine nucleotide regulatory protein (Gs), however, the stimulatory effects of 5'-O-(3-thiotriphosphate), isoproterenol, and N-ethylcarboxamide adenosine (NECA) on adenylyl cyclase activity were inhibited to various degrees by AII treatment. Staurosporine reversed the AII-evoked attenuation of isoproterenol- and NECA-stimulated enzyme activity. From these results, it can be suggested that AII, whose levels are increased in hypertension, may be one of the possible contributing factors responsible for exhibiting an enhanced expression of Gi protein in hypertension.

Involvement of phosphatidylinositol 3-kinase and mitogen-activated protein kinase pathways in AII-mediated enhanced expression of Gi proteins in vascular smooth muscle cells

We have previously demonstrated that angiotensin II increased Gialpha-2 and Gialpha-3 expression at both protein and mRNA levels in vascular smooth muscle cell (VSMC). The present study was undertaken to investigate the mechanisms responsible for AII-induced enhanced expression of Gi proteins. The levels of Gi protein were determinated by immunoblotting techniques using specific antibodies against Gialpha-2 and Gialpha-3. AII treatment of VSMC increased the levels of Gialpha-2 and Gialpha-3 proteins and actinomycin D, an inhibitor of RNA synthesis attenuated the AII-evoked enhanced expression of Gialpha-2 and Gialpha-3 proteins. In addition, wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI-3-K), rapamycin, an inhibitor of p70(S6K) and PD 098059, an inhibitor of mitogen-activated protein kinase (MAPK) kinase were able to inhibit AII-induced enhanced expression of Gialpha-2 and Gialpha-3 to various degrees. The attenuation of AII-evoked enhanced levels of Gialpha-2 and Gialpha-3 by PD 098059 was concentration dependent. At 50 microM, PD 098059 was able to completely attenuate the enhanced levels of Gialpha-2 and Gialpha-3 caused by AII treatment. These data suggest that the enhanced expression of Gi-proteins by AII treatment may be attributed to increased RNA synthesis of Gi-proteins, and MAPK kinase, PI-3-Kinase and p70(S6K) may be involved in AII-mediated increased expression of Gi-proteins in VSMC.

Angiotensinogen gene expression is stimulated by the cAMP-responsive element binding protein in opossum kidney cells

It has been reported previously that the addition of isoproterenol or forskolin stimulates the expression of the angiotensinogen (ANG) gene in opossum kidney (OK) 27 cells, an OK cell line with a fusion gene containing the 5'-flanking regulatory sequence of the rat ANG gene fused with a human growth hormone (hGH) gene as a reporter, pOGH (ANG N-1498/+18), permanently integrated into their genomes. To investigate whether the effect of isoproterenol or forskolin on the expression of the ANG gene is mediated via the nuclear 43-kD cAMP-responsive element binding protein (CREB), OK 27 cells were transiently transfected with an expression plasmid containing the cDNA for the 43-kD CREB (pRSV/CREB). The level of expression of the pOGH (ANG N-1498/+18) in OK 27 cells was estimated by the amount of immunoreactive hGH secreted into the culture medium. Transfection of pRSV/CREB alone stimulated the expression of pOGH (ANG N-1498/+18). The addition of isoproterenol or forskolin further enhanced the stimulatory effect of pRSV/ CREB on the expression of pOGH (ANG N-1498/+18). The enhancing effect of isoproterenol was inhibited by the presence of propranolol (an inhibitor of beta-adrenoceptors) and (R)-p-adenosine 3'5'-cyclic monophospho-orthioate (Rp)-cAMP (an inhibitor of cAMP-dependent protein kinase A I and II). Transfection of pRSV/CREB had no effect on the expression of thymidine kinase growth hormone in OK 13 cells, an OK cell line with a fusion gene containing the promoter/enhancer DNA sequence of the viral thymidine-kinase gene fused with an hGH gene as a reporter, thymidine kinase growth hormone, permanently integrated into their genomes. These studies demonstrate that isoproterenol stimulates the expression of ANG gene via the cAMP-dependent protein kinase A and probably via the interaction of the 43-kD CREB with the 5'-flanking region of the ANG gene. Our data indicate that the nuclear 43-kD CREB may have a modulatory role on the expression of the ANG gene in OK cells.

[DNA quantitative analysis of small bowel carcinoma and its clinical significance]

By using computer cytophotometric analysis, aneuploid as well as other 12 parameters of tissue DNA content were measured in 28 cases of small bowel cancer, 5 cases of intestinal adenoma, 6 cases of normal intestinal tissues. The number of aneuploid tumors in intestinal cancer was much higher than in intestinal adenoma. 7 DNA parameters (Entropy of DNA, 2CDI, DNA- grade of neoplasia, 5C Exceeding Rate, 9C Exceeding Rate, Diploid Deviation Quotient and Mean Ploidy) were the valuable indexes that could determine the quality of intestinal lesions, benign or malignant. DNA content didn't correlate with the clinically differentiated degree of pathological tissues, but aneuploid intestinal cancers had a higher malignant degree than non-aneuploid ones, and were more liable to invade and metastasize with low postoperative survival-rate and poor prognosis. 5 DNA parameters (DNA-Index, Medal Value, DNA-grade of neoplasia, Stemline Ploid and 9C Exceeding Rate) had close relation to the prognosis of intestinal cancer, possessing important value to the prognostic analysis of intestinal cancer.

[Study of p53 protein expression in cancers of small intestine and its relationship to clinical course and prognosis]

In order to study the relationship of p53 gene mutation with the occurrence and prognosis of cancer of small intestine, expression of p53 protein was examined. The results showed that p53 protein expression was high in 75% of small intestine cancer, and 21.1% positive in tissues close to cancer. In 7 cases of small intestinal adenoma only one was positive. Sixteen cases of normal tissue of intestine showed negative expression of p53 protein. The study also found that the degree of p53 protein expression was significantly correlated with the degree of tumor cell differention, invasion, metastasis and prognosis.

Bradyrhizobium liaoningense sp. nov., isolated from the root nodules of soybeans

Seventeen strains of extra-slowly growing (ESG) soybean rhizobia isolated from root nodules of Glycine soja and Glycine max growing in five provinces (Liaoning, Heilongjiang, Shanxi, Hubei, and Anhui) in the People's Republic of China were compared with 48 reference strains belonging to the genera Bradyrhizobium, Rhizobium, and Agrobacterium by performing a numerical analysis of 191 phenotypic features. Our results showed that all of the ESG strains examined clustered closely in the genus Bradyrhizobium but were separated from Bradyrhizobium japonicum at the species level and that they could be differentiated from Rhizobium and Agrobacterium species at the genus level. On the basis of the results of our numerical taxonomy analysis, a genomic DNA G & C content analysis, DNA-DNA hybridization experiments, a partial 16S rRNA sequence analysis, a serological analysis, an N and C content analysis, and an N/C ratio analysis of members of the three groups of soybean rhizobia, we propose the name Bradyrhizobium liaoningense sp. nov. for the ESG strains; the type strain of this species is strain 2281.