CDC-like kinase 3 deficiency aggravates hypoxia-induced cardiomyocyte apoptosis through AKT signaling pathway

Hypoxia-induced cardiomyocyte apoptosis is one major pathological change of acute myocardial infarction (AMI), but the underlying mechanism remains unexplored. CDC-like kinase 3 (CLK3) plays crucial roles in cell proliferation, migration and invasion, and nucleotide metabolism, however, the role of CLK3 in AMI, especially hypoxia-induced apoptosis, is largely unknown. The expression of CLK3 was elevated in mouse myocardial infarction (MI) models and neonatal rat ventricular myocytes (NRVMs) under hypoxia. Furthermore, CLK3 knockdown significantly promoted apoptosis and inhibited NRVM survival, while CLK3 overexpression promoted NRVM survival and inhibited apoptosis under hypoxic conditions. Mechanistically, CLK3 regulated the phosphorylation status of AKT, a key player in the regulation of apoptosis. Furthermore, overexpression of AKT rescued hypoxia-induced apoptosis in NRVMs caused by CLK3 deficiency. Taken together, CLK3 deficiency promotes hypoxia-induced cardiomyocyte apoptosis through AKT signaling pathway.

Lacticaseibacillus rhamnosus GG Improves Periodontal Bone Repair via Gut-Blood Axis in Hyperlipidemia

Periodontal bone regeneration remains a clinical challenge, and hyperlipidemia can aggravate alveolar bone resorption. Probiotics have recently been reported to improve bone mass. We aimed to determine the role of Lacticaseibacillus rhamnosus GG (LGG) in periodontal bone regeneration improvement within the context of periodontitis with hyperlipidemia. A Sprague Dawley rat model for periodontitis, hyperlipidemia, and periodontal fenestration defect was constructed (n = 36) and administered LGG gavage for 6 wk (the rats were subsequently sacrificed). Fecal microbiota from donor rats 3 wk after LGG gavage was transplanted into recipient rats to evaluate the role of LGG-modulated gut microbiota in periodontal bone regeneration. Regenerated bone mass was detected using micro-computerized tomography and hematoxylin and eosin stain. Gut microbiota was analyzed using 16S ribosomal RNA sequencing. Serum metabolites were detected by liquid chromatography-mass spectrometry (6 wk after LGG gavage). The pro-osteogenic effects of screened serum metabolite were verified in vitro on bone marrow mesenchymal stem cells (BMMSCs). We found that the bone mineral density, bone volume (BV), trabecular bone volume fraction (BV/TV), and trabecular thickness of the regenerated periodontal bone increased after LGG gavage (P < 0.05) but had little effect on oral flora. After LGG gavage, Staphylococcus, Corynebacterium, and Collinsella in the gut of donors were significantly changed, and these differences were maintained in recipients, who also showed increased trabecular thickness of the regenerated periodontal bone (P < 0.05). These key genera were correlated with BV/TV and BV (P < 0.05). In addition, LGG gavage significantly regulated bone-related blood metabolites, of which selenomethionine promoted BMMSC osteogenesis. Notably, selenomethionine was associated with key gut genera (P < 0.05). Collectively, LGG improved periodontal bone regeneration in the context of periodontitis with hyperlipidemia by modulating gut microbiota and increasing pro-osteogenic metabolites in the blood. These results reveal new insights into the use of probiotics to promote periodontal bone regeneration via the gut-blood-bone axis.

[Expert consensus on the management of adverse events of CDK4/6 inhibitors in breast cancer]

Cyclin-dependent kinases 4/6 (CDK4/6) inhibitors are anti-tumor agents for the treatment of hormone receptor-positive breast cancer. Palbociclib, abemaciclib and dalpiciclib have been approved for the treatment of breast cancer in China. Common adverse effects of CDK4/6 inhibitors include bone marrow suppression, gastrointestinal toxicities, liver dysfunction, and skin or subcutaneous tissue adverse reactions (AEs). The Breast Cancer Expert Group of Chinese Society of Clinical Oncology (CSCO) summarized the incidence, clinical manifestations, and grading of the AEs. This expert consensus reports measures of AE management on the basis of experience of clinical practice and the latest advances worldwide, aiming to guide clinical practice by the way of managing AE and help to choose the best treatment regimen.

[Analysis on the HIV-1 molecular transmission characteristics of newly confirmed HIV/AIDS in Jiaxing city, 2017-2018]

Objective: To analyze the relationship between infection and transmission of HIV/AIDS, explore the characteristics of the HIV-1 transmission network, and provide evidence for formulating targeted prevention and control measures. Methods: The newly confirmed HIV/AIDS in Jiaxing from 2017 to 2018 were selected for the study. The sociodemographic and infection transmission-related information was gathered. The blood samples were collected and RNA was extracted, RT-PCR and nested PCR amplified the pol gene of HIV-1. The phylogenetic tree was constructed by Mega 6.0 software for subtype analysis. The genetic distance between strains was calculated, and the molecular transmission network was drawn by using Cytoscape 3.6.0 software. The results of the epidemiological study based on the molecular transmission network were analyzed. Results: There were fifteen HIV-1 gene subtypes in 517 cases of HIV/AIDS. The main subtypes were CRF01_AE (37.1%)、CRF07_BC (36.2%) and CRF08_BC (11.8%). Under the 1.0% gene distance threshold, 87 molecular clusters were established, and the total clustering rate was 45.8% (237/517). The cluster risk factors were 60-81 age group (compared with 14-24 age group, OR=2.690, 95%CI:1.058-6.844), married (compared with unmarried, OR=1.698, 95%CI:1.003-2.875), CRF07_BC subtype (compared with CRF01_AE, OR=2.203, 95%CI:1.426-3.404). The largest molecular cluster, CRF07_BC-1, consisted of 50 cases (including 21 cases confirmed in 2017 cases and 29 confirmed in 2018). Multivariate analysis showed that characteristics of unmarried (compared with married, OR=2.482, 95%CI:1.140-5.402), gays (compared with heterosexual, OR=3.163, 95%CI:1.543-6.483), cases with high-risk transmission (compared with other cases, OR=7.631, 95%CI:1.783-32.654), confirmed in Nanhu and Pinghu districts of Jiaxing (compared with other districts, OR=2.225, 95%CI:1.074-4.608) were risks for entering the largest molecular cluster. There were seven suspected high-risk transmission MSM in the largest molecular cluster. The first debut of homosexual behavior was from 2010 to 2018, and the median number of gay partners was 20 (P₂₅, P₇₅：10, 100) within two years before being diagnosed. Six reported a recent history of looking for gay partners in an MSM dating place in Nanhu district. Conclusions: The HIV-1 subtypes of newly confirmed HIV/AIDS were diverse, mainly sporadic in Jiaxing from 2017 to 2018. There were geographical aggregation characteristics and suspected some high-risk transmission cases, suggesting that rapid transmission and targeted intensive intervention are needed.

[Clinicopathological features of polymorphous low-grade neuroepithelial tumor of the young]

Objective: To investigate the clinicopathological features, diagnosis and prognosis of polymorphous low-grade neuroepithelial tumor of the young (PLNTY). Methods: Two cases of PLNTY diagnosed during January 2016 to December 2019 were collected from Ningbo Diagnostic Pathology Center, Zhejiang, China. The clinical features, histopathological characteristics, immunohistochemical and molecular genetic findings were analyzed and the relevant literature was reviewed. Results: The two patients were both female, at the ages of 14 and 25 years, respectively. Both patients presented with seizure attacks. The imaging study showed a mixed signal in the cerebral cortex, located in the occipital and temporal lobes, respectively. Microscopically, the tumors were characterized by the invariable presence of oligodendroglioma-like appearance, often with calcification. Immunohistochemically, the tumors were diffusely and intensely CD34 positive with ramified, CD34-expressing neural elements in regional cortex. The tumors were positive for GFAP, Olig2 and ATRX, and negative for IDH1, Neu N, nestin and EMA. The Ki-67 labeling index was less than 2%. The case number 2 harbored the BRAF V600E mutation, while the case number 1 was negative for both the BRAF V600E mutation and 1p/19q codeletion. Both patients recovered very well and were free of seizures after the following-up of 2 and 24 months, respectively. Conclusions: PLNTY is an uncommon neuroepithelial tumor. Histopathologic and immunohistochemical examinations are necessary for establishing the diagnosis and for excluding oligodendroglioma. PLNTY should be considered as a benign tumor corresponding to WHO Grade I. The prognosis is overall good after complete tumor-resection.

Upregulated microRNA-126 induces apoptosis of dental pulp stem cell via mediating PTEN-regulated Akt activation

INTRODUCTION

Human dental pulp stem cells (DPSCs) have potential applications in regenerative medicine. The molecular mechanisms underlying DPSCs viability and apoptosis are not completely understood. Here, we investigated the role of miR-126 in DPSCs viability and apoptosis.

MATERIAL AND METHODS

Senescent DPSCs were compared with early passage DPSCs. real-time PCR and microARRAY were performed to identify the differential expression of miR-126, and western blot was performed to detect the expression of PTEN. MTT assay was utilized to reveal the proliferative rate of both senescent and early passage DPSCs. Flow cytometry was used to examine the apoptotic rate of DPSCs. Dual-luciferase reporter assay was carried out to detect the interaction of miR-126 and PTEN.

RESULTS

Senescent DPSCs showed a high level of apoptosis. Further study showed that miR-126 is upregulated in senescent DPSCs and its overexpression in early passaged DPSCs induced apoptosis. Phosphatase and tensin homolog gene (PTEN) was identified as a target of miR-126. PTEN was downregulated in senescent DPSCs, whereas miR-126 inhibition upregulated PTEN level, and subsequently activated Akt pathway and suppressed the apoptotic phenotype of senescent DPSCs. In addition, PTEN overexpression rescued apoptosis of DPSCs at later stage.

CONCLUSION

Our results demonstrate that the miR-126-PTEN-Akt axis plays a key role in the regulation of DPSCs apoptosis and provide a candidate target to improve the functional and therapeutic potential of DPSCs.

[Epidemiological characteristics of molecular transmission cluster among reported HIV/AIDS cases in Jiaxing city, Zhejiang province, 2017]

Objective: To understand the epidemiological characteristics of one large HIV molecular transmission cluster in Jiaxing city, Zhejiang province, 2017 in order to select those people under high-risk and providing basis for programs on prevention. Methods: During 2017, newly diagnosed HIV/AIDS cases in this city were recruited. Plasma samples were collected from subjects, followed by RNA extraction, RT-PCR and nest-PCR for pol gene amplification, before being sequenced and aligned. Mega 6.0 software was used to construct phylogenetic tree, and Cytoscape 3.6.0 software was used to identify HIV molecular transmission clusters. Cases within the large transmission clusters were investigated, using a field-epidemiology-questionnaire. Data related to socio-demographics and previous sexual behaviors were collected and EpiData 3.0 and SPSS 20.0 software were used. Results: In the large transmission cluster with subtype identified as CRF07_BC, in Jiaxing, 2017, 26 cases of the total 30 cases were investigated. A total of 80.8% (21/26) could be identified as newly infected within the last two years and 30.8%(8/26) could be identified as newly infected within the last one year, including 22 cases infected locally. Among several infected cases who were at age 45 years or older, they admitted that they had experienced unprotected sexual contacts in local city for long time and having had more than 10 disclosed sexual contacts within the last two years at the local venues. Conclusions: This molecular cluster had been formed and scaled up quickly in recent two years, it has played an important role in promoting and scaling up the HIV transmission. Three cases identificed as high risk played an importantrde role in scaling up this cluster.

Design for a Nanoscale Single-Photon Spin Splitter for Modes with Orbital Angular Momentum

We propose using the effective spin-orbit coupling of light in Bragg-modulated cylindrical waveguides for the efficient separation of spin-up and spin-down photons emitted by a single photon emitter. Because of the spin and directional dependence of photonic stop bands in the waveguides, spin-up (-down) photon propagation in the negative (positive) direction along the waveguide axis is blocked while the same photon freely propagates in the opposite direction. Frequency shifts of photonic band structures induced by the spin-orbit coupling are verified by finite-difference time-domain numerical simulations.

Changes in IL-4 and IL-13 expression in allergic-rhinitis treated with hydrogen-rich saline in guinea-pig model

BACKGROUND

Medical gas hydrogen (H₂) has a special role in airway inflammation; however, the effect of H₂ on allergic rhinitis (AR) remains unclear. This study explored the possible roles of H2 on the pathogenesis of AR and observed the influences of H₂ on cytokines IL-4 and IL-13.

METHODS

An AR guinea pig model was established by nasal ovalbumin sensitisation. Eighteen guinea pigs were divided into three groups, namely, saline control, AR-sensitised, and hydrogen-rich saline (HRS)-treated groups, with each group having six guinea pigs. The frequencies of sneezing and scratching were recorded. The IgE level and cytokine (IL-4 and IL-13) levels in the serum were measured. The expression levels of IL-4 and IL-13 mRNA and protein in the nasal mucosa were also determined by real-time reverse transcriptase-polymerase chain reaction and Western blot. We also observed the infiltration of cytokine (IL-4 and IL-13) in nasal mucosa by immunofluorescence.

RESULTS

The frequencies of sneezing and scratching, as well as the levels of IgE, IL-4, and IL-13, in the serum were higher in the AR group than in the control group (p<0.01), whereas all these parameters were decreased significantly after HRS treatment (p<0.05). The expression levels of IL-4 and IL-13 mRNA and protein in the nasal mucosa were also lower in guinea pigs treated with HRS than those in the AR group (p<0.05).

CONCLUSIONS

HRS could affect anti-inflammation in AR and decreased the expression of IL-4 and IL-13.

Isthmin targets cell-surface GRP78 and triggers apoptosis via induction of mitochondrial dysfunction

Isthmin (ISM) is a secreted 60-kDa protein that potently induces endothelial cell (EC) apoptosis. It suppresses tumor growth and angiogenesis in mice when stably overexpressed in cancer cells. Although αvβ5 integrin serves as a low-affinity receptor for ISM, the mechanism by which ISM mediates antiangiogenesis and apoptosis in ECs remain to be fully resolved. In this work, we report the identification of cell-surface glucose-regulated protein 78 kDa (GRP78) as a high-affinity receptor for ISM (Kd=8.6 nM). We demonstrated that ISM-GRP78 interaction triggers apoptosis not only in activated ECs but also in cancer cells expressing high level of cell-surface GRP78. Normal cells and benign tumor cells tend to express low level of cell-surface GRP78 and are resistant to ISM-induced apoptosis. Upon binding to GRP78, ISM is internalized into ECs through clathrin-dependent endocytosis that is essential for its proapoptotic activity. Once inside the cell, ISM co-targets with GRP78 to mitochondria where it interacts with ADP/ATP carriers on the inner membrane and blocks ATP transport from mitochondria to cytosol, thereby causing apoptosis. Hence, ISM is a novel proapoptotic ligand that targets cell-surface GRP78 to trigger apoptosis by inducing mitochondrial dysfunction. The restricted and high-level expression of cell-surface GRP78 on cancer cells and cancer ECs make them uniquely susceptible to ISM-targeted apoptosis. Indeed, systemic delivery of recombinant ISM potently suppressed subcutaneous 4T1 breast carcinoma and B16 melanoma growth in mice by eliciting apoptosis selectively in the cancer cells and cancer ECs. Together, this work reveals a novel ISM-GRP78 apoptosis pathway and demonstrates the potential of ISM as a cancer-specific and dual-targeting anticancer agent.

A meta-analysis of the relation of polymorphism at sites -1082 and -592 of the IL-10 gene promoter with susceptibility and clearance to persistent hepatitis B virus infection in the Chinese population

BACKGROUND

Up to now, many publications about the Chinese population have evaluated the correlation between interleukin-10 (IL-10) -1082 and -592 polymorphisms and persistent hepatitis B virus (HBV) infection. However, the results remain inconclusive. In order to resolve this conflict, a meta-analysis was performed.

METHODS

Seven studies were included and dichotomous data are presented as the odds ratio (OR) with a 95% confidence interval (CI).

RESULTS

The results of our study suggest that carriers of the IL-10 -592A allele were more likely to clear HBV spontaneously in the Chinese pooled population (A vs. C: OR = 0.799, 95% CI = 0.678-0.941, P = 0.007; AC vs. AA: OR = 1.343, 95% CI = 1.017-1.684, P = 0.011; AA vs. AC + CC: OR = 0.736, 95% CI = 0.594-0.912; AA + AC vs. CC: OR = 0.588, 95% CI = 0.408-0.848, P = 0.004) and the IL-10 -1082A allele was associated with significantly reduced persistent HBV infection risk in Chinese (A vs. G: OR = 0.701, 95% CI = 0.494-0.996, P = 0.047; AA vs. GG + GA: OR = 0.684, 95% CI = 0.476-0.982, P = 0.040).

CONCLUSIONS

Persistent HBV infection susceptibility is associated with the gene polymorphism IL-10 -1082GA in the Chinese population and the clearance of HBV is associated with the gene polymorphism IL-10 -592CA in the Chinese population.

Small volume laboratory on a chip measurements incorporating the quartz crystal microbalance to measure the viscosity-density product of room temperature ionic liquids

A microfluidic glass chip system incorporating a quartz crystal microbalance (QCM) to measure the square root of the viscosity-density product of room temperature ionic liquids (RTILs) is presented. The QCM covers a central recess on a glass chip, with a seal formed by tightly clamping from above outside the sensing region. The change in resonant frequency of the QCM allows for the determination of the square root viscosity-density product of RTILs to a limit of approximately 10 kg m(-2) s(-0.5). This method has reduced the sample size needed for characterization from 1.5 ml to only 30 mul and allows the measurement to be made in an enclosed system.

Modulation of 11beta-hydroxysteroid dehydrogenase expression by bombesin: a possible mechanism for glucocorticoid resistance in androgen independent prostate cancer

Treatment with glucocorticoids is one of a limited number of options for androgen independent prostate cancer. Neuroendocrine differentiation has been shown to contribute to androgen-independent prostate cancer progression. To study the potential link between neuroendocrine differentiation and the glucocorticoid action, we investigated the effects of the product of neuroendocrine differentiation--bombesin on glucocorticoid metabolizing enzymes--11beta-hydroxysteroid dehydrogenases in PC-3 cells. Our Western analysis, RT-PCR, and activity assays demonstrate that while 18-hour exposure to bombesin reduces 11beta-hydroxy-steroid dehydrogenases-1 profiles (activities 25% less, protein level 29% lower, mRNA levels 45% lower), contrarily it increases 11beta-hydroxysteroid dehydrogenases-2 profiles (activities 34%, protein levels 100%, mRNA levels 120%). Blockade bombesin action with bombesin receptor antagonists and the enzyme degrading bombesin prevented these changes, suggesting the observed modulations were bombesin receptor-specific. In addition, bombesin increased the amounts of interleukin-8 and mRNA of vascular endothelial growth factor receptor 2, which were lowered in the presence of cortisol, suggesting that neuropeptide blockade may extend the benefits of glucocorticoids in treating androgen-independent prostate cancer.

Developing Antiangiogenic Peptide Drugs for Angiogenesis-Related Diseases

Angiogenesis is regulated by stimulators and inhibitors and involve multiple biological processes including endothelial cell proliferation, migration, cell-cell and cell-matrix adhesion, assembly into tube structures as well as apoptosis. Designing and developing peptides for therapeutic application to inhibit angiogenesis is an important area in antiangiogenic drug development. Small peptides have advantages over proteins for therapeutic application, due to their stability, solubility, increased bio-availability and lack of immune response in the host cell. Endogenous protein angiogenesis stimulators and inhibitors hold vital information for designing antiangiogenic peptides for drug development. These proteins function through their interaction with extracellular matrix molecules, cell surface receptors, proteases, as well as growth factors and cytokines. Conserved domains such as thrombospondin type 1 repeats (TSRs), kringle domains as well as critical amino acid residues present in these domains are involved in their functions. By exploiting these properties, several small peptides have been designed, synthetically made and being tested for therapeutic efficacy. Peptides derived from type 1 repeat of thrombospondin, alpha 4 and beta 1 chains of laminin, arginine rich N terminus of endostatin, leucine rich repeat 5 of decorin, pigment epithelium derived factor and N terminal of parathyroid hormone are examples of small antiangiogenic peptides derived from endogenous proteins. Such bioactive peptides are further modified physico-chemically to increase their potency and stability. In addition, phage-display library screening and combinatorial approach are also in use to identify novel antiangiogenic peptides targeting tumour and various proteins. This review will provide a comprehensive summary of the current status of the antiangiogenic peptides and their relevance for drug designing and development. Several critical issues that need to be resolved in translating this concept into clinical practice are also discussed.

Adding functional entities to plasmids

Non-viral gene therapy constitutes an alternative to the more common use of viral-mediated gene transfer. Most gene transfer methods using naked DNA are based upon non-sequence-specific interactions between the nucleic acid and cationic lipids (lipoplex) or polymers (polyplex). We have developed a technology in which functional entities hybridize in a sequence-specific manner to the nucleic acid (bioplex). This technology is still in its infancy, but has the potential to become a useful tool, since it allows the construction of highly defined complexes containing a variety of functional entities. In its present form the bioplex technology is based upon the use of peptide/nucleic acids (PNA) as anchors. Single, or multiple, functional entities are directly coupled to the anchors. By designing plasmids, or oligonucleotides, with the corresponding anchor target sequence, complexes with desired composition can easily be generated. The long-term aim is to combine functional entities in order to achieve optimal, synergistic interactions allowing enhanced gene transfer in vivo.

Modulation of rat Leydig cell steroidogenic function by di(2-ethylhexyl)phthalate

Exposure of rodents to phthalates is associated with developmental and reproductive anomalies, and there is concern that these compounds may be causing adverse effects on human reproductive health. Testosterone (T), secreted almost exclusively by Leydig cells in the testis, is the primary steroid hormone that maintains male fertility. Leydig cell T biosynthesis is regulated by the pituitary gonadotropin LH. Herein, experiments were conducted to investigate the ability of di(2-ethylhexyl)phthalate (DEHP) to affect Leydig cell androgen biosynthesis. Pregnant dams were gavaged with 100 mg(-1) kg(-1) day(-1) DEHP from Gestation Days 12 to 21. Serum T and LH levels were significantly reduced in male offspring, compared to control, at 21 and 35 days of age. However, these inhibitory effects were no longer apparent at 90 days. In a second set of experiments, prepubertal rats, from 21 or 35 days of age, were gavaged with 0, 1, 10, 100, or 200 mg(-1) kg(-1) day(-1) DEHP for 14 days. This exposure paradigm affected Leydig cell steroidogenesis. For example, exposure of rats to 200 mg(-1) kg(-1) day(-1) DEHP caused a 77% decrease in the activity of the steroidogenic enzyme 17beta-hydroxysteroid dehydrogenase, and reduced Leydig cell T production to 50% of control. Paradoxically, extending the period of DEHP exposure to 28 days (Postnatal Days 21-48) resulted in significant increases in Leydig cell T production capacity and in serum LH levels. The no-observed-effect-level and lowest-observed-effect-level were determined to be 1 mg(-1) kg(-1) day(-1) and 10 mg(-1) kg(-1) day(-1), respectively. In contrast to observations in prepubertal rats, exposure of young adult rats by gavage to 0, 1, 10, 100, or 200 mg(-1) kg(-1) day(-1) DEHP for 28 days (Postnatal Days 62-89) induced no detectable changes in androgen biosynthesis. In conclusion, data from this study show that DEHP effects on Leydig cell steroidogenesis are influenced by the stage of development at exposure and may occur through modulation of T-biosynthetic enzyme activity and serum LH levels.

The role of vascular endothelial growth factor (VEGF) in vasculogenesis, angiogenesis, and hematopoiesis in zebrafish development

Vascular endothelial growth factor (VEGF, VEGF-A), a selective mitogen for endothelial cells is a critical factor for vascular development. Two isoforms that differ in the presence of exons 6 and 7, Vegf(165) and Vegf(121), are the dominant forms expressed in zebrafish embryo. Simultaneous overexpression of both isoforms in the embryo results in increased production of flk1, tie1, scl, and gata1 transcripts, indicating a stimulation of both endothelial and hematopoietic lineages. We also demonstrate that vegf can stimulate hematopoiesis in zebrafish by promoting the formation of terminally differentiated red blood cells. Simultaneous overexpression of both isoforms also causes ectopic vasculature and blood cells in many of the injected embryos as well as pericardial edema in later stage embryos. Overexpression of vegf also resulted in earlier onset of flk1, tie1, scl, and gata1 expression in the embryo, indicating a possible role of vegf in stimulating the differentiation of both vascular and hematopoietic lineages. Co-injection of RNAs for both isoforms results in increased expression of three of these markers over and above that observed when either RNA is singly injected and analysis of vegf expression in the notochord mutants no tail and floating head suggests that the notochord patterns the formation of the dorsal aorta by stimulating adjacent somite cells to express vegf, which in turn functions as a signal in dorsal aorta patterning. Finally, studies of vegf expression in cloche mutant indicate that vegf expression is generally independent of cloche function. These results show that in the zebrafish embryo, vegf can not only stimulate endothelial cell differentiation but also hematopoiesis. Moreover, these effects are most dramatic when both vegf isoforms are co-expressed, indicating a synergistic effect of the expression of the two forms of the VEGF protein.

Inhibition of angiopoietin-1 expression in tumor cells by an antisense RNA approach inhibited xenograft tumor growth in immunodeficient mice

Angiopoietin-1 (Ang1) is an angiogenic growth factor that functions through activation of its endothelium-specific tyrosine kinase receptor Tie2; it mediates the interaction between endothelial and surrounding cells to promote the remodeling, maturation and stabilization of blood vessels. Although Ang1 is expressed constitutively in many adult tissues, its role in tumor growth and metastasis is not clear. Here we describe experiments in which Ang1 expression was inhibited in HeLa cells by an antisense RNA approach. The modified HeLa cells produced significantly less Ang1 protein both in cultured cells and in tumors formed when these cells were injected into immunodeficient mice. The Ang1 antisense tumors grew much more slowly, with significantly reduced tumor angiogenesis compared with control tumors. Furthermore, they also had substantially increased tumor cell apoptosis and decreased tumor necrosis. Our results indicate that the perturbation of Ang1 expression in tumors could be an effective method to control tumor growth by inhibiting tumor angiogenesis and that antisense RNA is an efficient way to inhibit Ang1 protein production in tumor cells.

The effect of dichloroacetic acid and trichloroacetic acid on DNA methylation and cell proliferation in B6C3F1 mice

The chlorine disinfection by-products, dichloroacetic acid (DCA) and trichloroacetic acid (TCA), are carcinogenic in mouse liver. We have previously reported that DCA and TCA induced DNA hypomethylation in mouse liver. In the present study, we determined the temporal association for DNA hypomethylation and cell proliferation. Female B6C3F1 mice were administered daily doses of 500 mg/kg DCA or TCA by gavage and sacrificed at 24, 36, 48, 72, and 96 hours after the first dose. The proliferating cell nuclear antigen-labeling index in the liver was increased at 72 and 96 hours by both DCA and TCA, that is, at 72 hours the index was 1.00 +/- 0.21, 0.51 +/- 0.11, and 0.095 +/- 0.016 for DCA, TCA, and the vehicle control, respectively. The mitotic index was also significantly increased at 96 hours. The promoter region for the c-myc gene was hypomethylated only at 72 and 96 hours and not at the earlier sacrifices. Similarly, the methylation of the c-myc gene in the kidney and urinary bladder was decreased only at 72 and 96 hours. In summary, enhancement of cell proliferation and decreased methylation of the c-myc gene were first observed simultaneously at 72 hours after the start of exposure. Thus, the results support the hypothesis that DCA and TCA induce DNA hypomethylation by inducing DNA replication and preventing the methylation of the newly synthesized strands of DNA.

Wy-14,643-induced hypomethylation of the c-myc gene in mouse liver

The carcinogenic activity of Wy-14,643 in mouse liver appears to be nongenotoxic and could involve a decrease in DNA methylation. The mechanism for Wy-14,643-induced decrease in DNA methylation is proposed to involve increased cell proliferation followed by prevention of the methylation of the newly synthesized DNA. To investigate this mechanism, female B6C3F1 mice were administered daily by oral gavage 50 mg/kg Wy-14,643. Mice were sacrificed at 2, 5, 8, 24, 26, 29, 32, 36, 48, 72, and 96 h after the first dose. Some mice also received 450 mg/kg methionine by ip injection at 30 min after administering Wy-14,643. Hypomethylation of the c-myc gene first occurred at 48 h after the first dose of Wy-14,643. Cell proliferation determined by the Proliferating Cell Nuclear Antigen (PCNA)-Labeling Index started to increase at 36 h and peaked at 72h. Wy14,643 did not affect the liver concentration of either S-adenosyl methionine (SAM) or S-adenosyl homocysteine (SAH). Methionine prevented and reversed the hypomethylation of the c-myc gene induced by Wy-14,643. However, the increased levels of SAM and SAH returned to control levels prior to the prevention by methionine of Wy-14,643-induced hypomethylation. Furthermore, methionine did not prevent Wy-14,643-induced increase in the PCNA-Labeling Index. The activity of nuclear DNA methyltransferase (DNA MTase) was increased at 72 and 96 h after administering Wy14,643. Wy14,643 also increased the activity of DNA MTase when added in vitro to nuclear extracts. The results are consistent with Wy-14,643 decreasing the methylation of the c-myc gene by a mechanism that includes enhancement of cell proliferation followed by prevention of the methylation of the newly synthesized DNA. However, the results indicate that Wy-14,643 does not prevent methylation by decreasing either the availability of SAM or the activity of DNA MTase.

[Recognizing of the transglottic carcinoma]

OBJECTIVE

A study was undergone about transglottic carcinoma(TGC) in eighty six cases from 1979 to 1998, so as to recognize the TGC.

METHOD

Evaluating retrospectively the procedure of the disease, surgical operations, presence of cervical metastasis, gathering the data on histopathological discovery and following up and so on.

RESULT

The TGC was different from T2, T3 supraglottic or glottic carcinoma of larynx. In 86 TGC, there were 63 cases which were operated with total laryngectomy, 9 cases subtotal laryngectomy and 14 cases frontolateral hemilaryngectomy, 47 cases with neck dissection. In TGC which size > 2 cm, there were 58% which extend to the framework of larynx, 46% with extension out of larynx, and 71% with neck metastasis. The result of following up shows that 5-year survival rate was 55.41%, 10-year was 29.72%, 15-year and more was 18.92%.

CONCLUSION

There is an actual signification for TGC to be a special type of the laryngeal carcinoma. The characteristics of the precise topography of the the paraglottic space (PGS) can explain the reason of extension, spread of the TGC and cervical metastasis. Elective neck dissections and complemental radiotherapy postoperatively should be included during surgical resection.

A small peptide derived from Flt-1 (VEGFR-1) functions as an angiogenic inhibitor

Vascular endothelial growth factor (VEGF) is an angiogenic stimulator which functions through two endothelial specific tyrosine kinase receptors, Flt-1 and Flk-1. In this work, we show that an 11-amino acid peptide derived from the second immunoglobulin-like domain of Flt-1 functions as an angiogenic inhibitor in chick chorioallantoic membrane and inhibited VEGF-induced vascular permeability in Miles' assay without binding to VEGF directly. Circular dichroism and nuclear magnetic resonance analyses indicate that this peptide forms a stable extended structure in solution, presumably beta-sheet structure and is most likely existing as a dimer. Our results suggest that this small peptide functions as an angiogenic inhibitor by inhibiting VEGF function through a non-VEGF binding mechanism.

fgfr3 and regionalization of anterior neural tube in zebrafish

Here we describe the isolation of the zebrafish fgfr3 gene, its structure and chromosomal location. Expression in wild type embryos occurs in the axial mesoderm, the diencephalon, the anterior hindbrain and the anterior spinal cord. In the hindbrain, a differential expression of fgfr3 was detected at several levels of intensity, with the highest expression in the posterior rhombomere 1 that is morphologically distinct from the anterior part, which develops into the cerebellum. Further, analysis of fgfr3 expression in mutants deficient in the formation of the midbrain-hindbrain boundary (MHB), noi(-/-) and ace(-/-), demonstrated that in the absence of Pax2.1 and FGF8 activity, the expression domains of FGFR3 expand into the MHB, tegmentum, cerebellum and optic tectum, which are the affected structures in these mutants.

Effect of trihalomethanes on cell proliferation and DNA methylation in female B6C3F1 mouse liver

Trihalomethanes (chloroform, bromodichloromethane, chlorodibromomethane, and bromoform) are regulated organic contaminants in chlorinated drinking water. In female B6C3F1 mouse liver, the 4 trihalomethanes have demonstrated carcinogenic activity when administered by oral gavage; however, chloroform was not carcinogenic when administered in drinking water. Female B6C3F1 mice were administered the trihalomethanes for 11 days by gavage at 2 dose levels or in the drinking water at approximately 75% saturation. When administered by gavage, the trihalomethanes were toxic to the liver, increased the liver:body weight (bw) ratio, and increased the proliferating cell nuclear antigen-labeling index (PCNA-LI). Chloroform and bromodichloromethane were the most toxic, and they increased the liver:bw ratio the most, while bromoform and chloroform increased the PCNA-LI the most. When administered in drinking water, the toxicity of the trihalomethanes was similar to their low gavage-dose. Furthermore, only chloroform significantly increased the liver:bw ratio and bromoform and chloroform increased the PCNA-LI. Chloroform and bromodichloromethane decreased the level of 5-methylcytosine in hepatic DNA. Methylation in the promoter region of the c-myc gene was reduced by the trihalomethanes. Chloroform administered by gavage was more efficacious than given in drinking water; the efficacy of the other trihalomethanes did not differ for the 2 routes. Thus, in mouse liver, the trihalomethanes administered by gavage enhanced cell proliferation and decreased the methylation of the c-myc gene, consistent with their carcinogenic activity. Furthermore, the more modest toxicity, enhancement of cell proliferation, and decreased methylation induced by chloroform administered in drinking water correlated with its lack of carcinogenic activity. Hence, the activity of the trihalomethanes was dependent on the rate of delivery, i.e. rapid by oral gavage and more slowly in drinking water.

Effect of trichloroethylene on DNA methylation and expression of early-intermediate protooncogenes in the liver of B6C3F1 mice

Trichloroethylene (TCE) is a multimedia environmental pollution that is carcinogenic in mouse liver. The ability of TCE to modulate DNA methylation and the expression of immediate-early protooncogenes was evaluated. Female B6C3F1 mice were administered 1000 mg/kg TCE by gavage 5 days/week and killed after 5, 12, or 33 days of exposure. Methylation of DNA as 5-methylcytosine was decreased by 5 days of treatment with TCE and remained reduced for 33 days. TCE also decreased the methylation of the promoter regions for the protooncogenes, c-jun and c-myc. The expression of the mRNA for the two protooncogenes was increased between 60 and 120 minutes after administering the last dose of TCE and returned to control level by 24 hours. The expression of the mRNA for c-fos remained undetectable after administering TCE. Hence, TCE decreased the methylation both of total DNA and the promoters for the c-jun and c-myc genes and increased the expression of their mRNA. The decreased methylation and increased expression of the two immediate-early protooncogenes might be associated with TCE-induced increase in cell proliferation and promotion of tumors.

[Community -based comprehensive prevention and control of hypertension in China (CCPACH Study)-prevalence and epidemiological characteristics in urban and rural area]

OBJECTIVE

To understand the epidemiological features and prevalence of essential hypertension in the rural communities.

METHODS

A community-based survey on essential hypertension was carried out in urban and rural areas involving 280,000 population.

RESULTS

The prevalence rate of hypertension in age 35 years and over was 31.7% and 32.9% in urban and rural respectively; the average age of the patients' in urbans was significantly higher than in rural areas. Among non-hypertensive cases, more than 50% of the population having risk factors of hypertension in both urban and rural areas. Rates of treatment and control awareness of hypertension were 56.3%, 26.8% and 4.4% respectively in urban; comparing to 40.3%, 17.5% and 2.6% respectively, in the rural areas. More than half of the diagnosed patients before survey did not take antihypertensive medicine for treatment in both areas. The proportions the classification of hypertension were similar in both areas with majority of them, mild and isolated systolic hypertension.

CONCLUSIONS

It was demonstrated that there is an urgent need to carry out comprehensive prevention and control for hypertension in urban and rural area.

[Changes of pulmonary diffusing capacity in subjects with acute mountain sickness]

OBJECTIVE

The study was conducted to investigate whether the changes in the pulmonary diffusing capacity found in individuals with acute mountain sickness (AMS) reflect the early stage of high-altitude pulmonary edema (HAPE).

METHODS

According to international definition of AMS (Lake Louise Consensus) thirty-two subjects were divided into AMS and non-AMS group. The pulmonary diffusion capacity for carbon monoxide (DLco) by the single-breath method, arterialized capillary blood gas were measured in all subjects at an altitude of 2,260 m and after ascent to 4,700 m.

RESULTS

All subjects exhibited an increase in DLco from 2,260 m to 4,700 m, the degree of increase in DLco in the AMS group was significantly lower than that of the non-AMS group, delta DLco (1.3 +/- 1.7) ml.min-1.mm Hg-1 vs (10.7 +/- 1.3) ml.min-1.mm Hg-1 (P > 0.01). The AMS group showed a greater alveolar-arterial oxygen pressure difference at 4,700 m compared with the non-AMS group. DLco showed a significantly negative correlation with AMS score (r = -0.885 P < 0.01).

CONCLUSIONS

These results suggest that the decreased pulmonary diffusing capacity has an important role in the incidence of acute mountain sickness, it reflects the presence of pulmonary gas exchange abnormality, which is probably due to subclinical interstitial edema of the lung.

Seeds induced to germinate rapidly by mentally projected 'qi energy' are apparently genetically altered

Mentally controlled qi energy can induce crop seeds to sprout and root for several cm within about 20 min. The RAPD method was used to compare treated groups of wheat and pea seeds and their controls using 11 selected primers. Seven primers amplified polymorphisms in wheat seeds and 5 in pea seeds. It was thought preliminarily that qi energy changed the structure of a germination-correlated gene site speeding up expression and advancing it in time.

Genetically manipulated animals and their use in experimental research

Genetically manipulated animals generated by transgenic and gene-targeting (knockout) technology have contributed tremendously to our understanding of gene function and regulation at the molecular level in the context of the whole organism. They are also becoming powerful tools for human disease studies and therapeutic drug development. An overview of the current development of these animals and their application in biological and medical researches is provided in this article.