DUSP1 promotes senescence of retinoblastoma cell line SO-Rb5 cells by activating AKT signaling pathway

OBJECTIVE

Retinoblastoma seriously threats to human health and life. Molecular targeted therapy of retinoblastoma supplies the direction of research in the future. This study aims to investigate the impact of DUSP1 on human retinoblastoma SO-Rb5 cell senescence.

MATERIALS AND METHODS

Angiotensin II (AGII) was used to induce human retinoblastoma SO-Rb5 cell senescence model. DUSP1 over-expression plasmid and small interfere RNA (siRNA) were transfected into SO-Rb5 cells by Lipofectamine. Dual specificity phosphatase 1 (DUSP1), p53, p16, and protein kinase B (Akt) signaling expressions were detected with Western blot assay. SH-6 was applied to inhibit Akt signaling in SO-Rb5 cells. Cell senescence was evaluated by using β-galactosidase test.

RESULTS

DUSP1 level increased in SO-Rb5 cells induced by AGII. Senescence protein p53 and p16 significantly upregulated in SO-Rb5 cell senescence model, together with β-galactosidase staining. DUSP1 plasmid transfection significantly enhanced DUSP expression, triggered SO-Rb5 cell senescence, and inhibited Akt signaling activation. DUSP1 siRNA exhibited the opposite effects. SH-6 significantly increased SO-Rb5 cell senescence induced by AGII through inhibiting Akt signaling.

CONCLUSIONS

DUSP1 facilitated human retinoblastoma SO-Rb5 cell senescence induced by AGII through inhibiting Akt signaling pathway.

Co-aggregation of major psychiatric disorders in individuals with first-degree relatives with schizophrenia: a nationwide population-based study

A previous genetic study has suggested that schizophrenia, bipolar disorder, major depressive disorder, autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) share common disease-associated genes. However, whether individuals with first-degree relatives (FDRs) with schizophrenia have a higher risk of these major psychiatric disorders requires further investigation. This study used Taiwan's National Health Insurance Research Database and identified 151 650 patients with schizophrenia and 227 967 individuals with FDRs with schizophrenia. The relative risks (RRs) of schizophrenia and other major psychiatric disorders were assessed in individuals with FDRs with schizophrenia. The individuals with FDRs with schizophrenia exhibited higher RRs (95% confidence interval) of major psychiatric disorders, namely schizophrenia (4.76, 4.65-4.88), bipolar disorder (3.23, 3.12-3.35), major depressive disorder (2.05, 2.00-2.10), ASD (2.55, 2.35-2.77) and ADHD (1.31, 1.25-1.37) than were found in the total population. Several sensitivity analyses were conducted to confirm these results. A dose-dependent relationship was observed between the risks of major psychiatric disorders and the numbers of FDRs with schizophrenia. The increased risks of major psychiatric disorders were consistent in different family relationships, namely among parents, offspring, siblings and twins. Our study supports the familial dose-dependent co-aggregation of schizophrenia, bipolar disorder, major depressive disorder, ASD and ADHD, and our results may prompt governmental public health departments and psychiatrists to focus on the mental health of individuals with FDRs with schizophrenia.

Electronic and atomic structures of the Sr3Ir4Sn13 single crystal: A possible charge density wave material

X-ray scattering (XRS), x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) spectroscopic techniques were used to study the electronic and atomic structures of the high-quality Sr₃Ir₄Sn₁₃ (SIS) single crystal below and above the transition temperature (T^* ≈ 147 K). The evolution of a series of modulated satellite peaks below the transition temperature in the XRS experiment indicated the formation of a possible charge density wave (CDW) in the (110) plane. The EXAFS phase derivative analysis supports the CDW-like formation by revealing different bond distances [Sn₁₍₂₎-Sn₂] below and above T^* in the (110) plane. XANES spectra at the Ir L₃-edge and Sn K-edge demonstrated an increase (decrease) in the unoccupied (occupied) density of Ir 5d-derived states and a nearly constant density of Sn 5p-derived states at temperatures T < T^* in the (110) plane. These observations clearly suggest that the Ir 5d-derived states are closely related to the anomalous resistivity transition. Accordingly, a close relationship exists between local electronic and atomic structures and the CDW-like phase in the SIS single crystal.

Proving Nontrivial Topology of Pure Bismuth by Quantum Confinement

The topology of pure Bi is controversial because of its very small (∼10  meV) band gap. Here we perform high-resolution angle-resolved photoelectron spectroscopy measurements systematically on 14-202 bilayer Bi films. Using high-quality films, we succeed in observing quantized bulk bands with energy separations down to ∼10  meV. Detailed analyses on the phase shift of the confined wave functions precisely determine the surface and bulk electronic structures, which unambiguously show nontrivial topology. The present results not only prove the fundamental property of Bi but also introduce a capability of the quantum-confinement approach.

The common CARD14 gene missense polymorphism rs11652075 (c.C2458T/p.Arg820Trp) is associated with psoriasis: a meta-analysis

Recent genetic evidence suggests a robust association of the CARD14 single nucleotide polymorphism rs11652075 (c.C2458T/p.Arg820Trp) and other rare mutations in this gene with psoriasis. To assess whether combined data support the relationship between CARD14 rs11652075 and susceptibility to this disease, we conducted a meta-analysis. PubMed (MEDLINE), EMBASE, Web of Science, and the Cochrane Library were searched for relevant papers published in English. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using random-effect models. Heterogeneity between studies was assessed using the Cochran's Q and I² statistics. A total of five published studies, including 32,807 psoriasis patients and 45,458 controls, met our inclusion criteria and were included in the meta-analysis. The pooled OR of the association between the minor allele of this polymorphism and psoriasis was 0.877 (95%CI = 0.834-0.922; P < 0.001). In a stratified analysis, pooled ORs relating to European and Asian ancestry were 0.883 (95%CI = 0.822-0.948) and 0.872 (95%CI = 0.812-0.936), respectively. Those calculated for studies with case sample sizes above and below 1000 were 0.912 (95%CI = 0.870- 0.956) and 0.824 (95%CI = 0.734-0.924), respectively. No publication bias was present, and the exclusion of any single dataset did not substantially alter the corresponding pooled ORs. Due to the limited data available regarding clinical classification of cases and genotypes, subgroup stratification by clinical type was not performed. Our results demonstrate a significant association between the CARD14 rs11652075 polymorphism and psoriasis.

Development of a millimetrically scaled biodiesel transesterification device that relies on droplet-based co-axial fluidics

In this study, we investigated a fluidic system that adheres to new concepts of energy production. To improve efficiency, cost, and ease of manufacture, a millimetrically scaled device that employs a droplet-based co-axial fluidic system was devised to complete alkali-catalyzed transesterification for biodiesel production. The large surface-to-volume ratio of the droplet-based system, and the internal circulation induced inside the moving droplets, significantly enhanced the reaction rate of immiscible liquids used here – soybean oil and methanol. This device also decreased the molar ratio between methanol and oil to near the stoichiometric coefficients of a balanced chemical equation, which enhanced the total biodiesel volume produced, and decreased the costs of purification and recovery of excess methanol. In this work, the droplet-based co-axial fluidic system performed better than other methods of continuous-flow production. We achieved an efficiency that is much greater than that of reported systems. This study demonstrated the high potential of droplet-based fluidic chips for energy production. The small energy consumption and low cost of the highly purified biodiesel transesterification system described conforms to the requirements of distributed energy (inexpensive production on a moderate scale) in the world.

Anomalous spectral features of a neutral bilayer graphene

Graphene and its bilayer are two-dimensional systems predicted to show exciting many-body effects near the neutrality point. The ideal tool to investigate spectrum reconstruction effects is angle-resolved photoemission spectroscopy (ARPES) as it probes directly the band structure with information about both energy and momentum. Here we reveal, by studying undoped exfoliated bilayer graphene with ARPES, two essential aspects of its many-body physics: the electron-phonon scattering rate has an anisotropic k-dependence and the type of electronic liquid is non-Fermi liquid. The latter behavior is evident from an observed electron-electron scattering rate that scales linearly with energy from 100 meV to 600 meV and that is associated with the proximity of bilayer graphene to a two-dimensional quantum critical point of competing orders.

Snapshots of Dirac fermions near the Dirac point in topological insulators

The recent focus on topological insulators is due to the scientific interest in the new state of quantum matter as well as the technology potential for a new generation of THz optoelectronics, spintronics and quantum computations. It is important to elucidate the dynamics of the Dirac fermions in the topologically protected surface state. Hence we utilized a novel ultrafast optical pump mid-infrared probe to explore the dynamics of Dirac fermions near the Dirac point. The femtosecond snapshots of the relaxation process were revealed by the ultrafast optics. Specifically, the Dirac fermion-phonon coupling strength in the Dirac cone was found to increase from 0.08 to 0.19 while Dirac fermions were away from the Dirac point into higher energy states. Further, the energy-resolved transient reflectivity spectra disclosed the energy loss rate of Dirac fermions at room temperature was about 1 meV/ps. These results are crucial to the design of Dirac fermion devices.

CHMP6 and VPS4A mediate the recycling of Ras to the plasma membrane to promote growth factor signaling

While Ras is well-known to function on the plasma membrane (PM) to mediate growth factor signaling, increasing evidence suggests that Ras has complex roles in the cytoplasm. To uncover these roles, we screened a cDNA library and isolated H-Ras-binding proteins that also influence Ras functions. Many isolated proteins regulate trafficking involving endosomes; CHMP6/VPS20 and VPS4A, which interact with ESCRT-III, were chosen for further study. We showed that the binding is direct and occurs in endosomes. Furthermore, the binding is most efficient when H-Ras has a functional effector-binding-loop and is GTP-bound and ubiquitylated. CHMP6 and VPS4A also bound N-Ras, but not K-Ras. Repressing CHMP6 and VPS4A blocked Ras-induced transformation, which correlated with inefficient Ras localization to the PM as measured by cell fractionation and photobleaching. Moreover, silencing CHMP6 and VPS4A also blocked EGFR recycling. These data suggest that Ras interacts with key ESCRT-III components to promote recycling of itself and EGFR back to the PM to create a positive feedback loop to enhance growth factor signaling.

Hemisphere Differences in Accessing Lexical Knowledge of Chinese Characters

The lateralisation of lexical knowledge of Chinese characters is investigated in this study. Three experiments were conducted in which stimuli were presented unilaterally to a visual field for recognition tests. The orthographic similarity of two alternative items for choice in Experiment 1 was manipulated, and the results showed an LVF advantage effect for legal characters in the visually similar condition and a more prominent LVF than RVF character-superiority effect. The phonological similarity of two alternative items for choice was manipulated in Experiment 2. The results showed a prominent RVF advantage effect and a significant phonological similarity effect in the RVF. In Experiment 3, the semantic similarity was manipulated, and the semantic similarity effect was observed in the RVF. These results suggest hemisphere asymmetries in accessing lexical knowledge of Chinese characters.

Optimal electron doping of a C60 monolayer on Cu(111) via interface reconstruction

We demonstrate the charge state of C60 on a Cu(111) surface can be made optimal, i.e., forming C60(3-) as required for superconductivity in bulk alkali-doped C60, purely through interface reconstruction rather than with foreign dopants. We link the origin of the C60(3-) charge state to a reconstructed interface with ordered (4x4) 7-atom vacancy holes in the surface. In contrast, C60 adsorbed on unreconstructed Cu(111) receives a much smaller amount of electrons. Our results illustrate a definitive interface effect that affects the electronic properties of molecule-electrode contact.

Novel electronic structure induced by a highly strained oxide interface with incommensurate crystal fields

The misfit oxide, Bi2Ba1.3K0.6Co2.1O7.94, made of alternating rocksalt-structured [BiO/BaO] layers and hexagonal CoO2 layers, was studied by angle-resolved photoemission spectroscopy, revealing the electronic structure of a highly strained oxide interface. We found that low-energy states are confined within individual sides of the interface, but scattered by the incommensurate crystal field from the other side. Furthermore, the high strain on the rocksalt layer induces large charge transfer to the CoO2 layer, and a novel effect, the interfacial enhancement of electron-phonon interactions, is discovered.

High-energy scale revival and giant kink in the dispersion of a cuprate superconductor

In the present photoemission study of a cuprate superconductor Bi1.74Pb0.38Sr1.88CuO6+delta, we discovered a large scale dispersion of the lowest band, which unexpectedly follows the band structure calculation very well. Similar behavior observed in blue bronze and the Mott insulator Ca2CuO2Cl2 suggests that the origin of hopping-dominated dispersion in an overdoped cuprate might be quite complicated. A giant kink in the dispersion is observed, and the complete self-energy containing all interaction information is extracted for a doped cuprate. These results recovered significant missing pieces in our current understanding of the electronic structure of cuprates.

Gene expression imaging by enzymatic catalysis of a fluorescent probe via membrane-anchored beta-glucuronidase

Development of nonimmunogenic and specific reporter genes to monitor gene expression in vivo is important for the optimization of gene therapy protocols. We developed a membrane-anchored form of mouse beta-glucuronidase (mbetaG) as a reporter gene to hydrolyze a nonfluorescent glucuronide probe (fluorescein di-beta-D-glucuronide, (FDGlcU) to a highly fluorescent reporter to assess the location and persistence of gene expression. A functional beta-glucuronidase (betaG) was stably expressed on the surface of murine CT26 colon adenocarcinoma cells where it selectively hydrolyzed the cell-impermeable FDGlcU probe. FDGlcU was also preferentially converted to fluorescent probe by (betaG) on CT26 tumors. The fluorescent intensity in betaG-expressing CT26 tumors was 240 times greater than the intensity in control tumors. Selective imaging of gene expression was also observed after intratumoral injection of adenoviral betaG vector into carcinoma xenografts. Importantly, mbetaG did not induce an antibody response after hydrodynamic plasmid immunization of Balb/c mice, indicating that the reporter gene product displayed low immunogenicity. A membrane-anchored form of human betaG also allowed in vivo imaging, demonstrating that human betaG can be employed for imaging. This imaging system therefore, displays good selectivity with low immunogenicity and may help assess the location, magnitude and duration of gene expression in living animals and humans.

A membrane antibody receptor for noninvasive imaging of gene expression

Monitoring gene expression is important to optimize gene therapy protocols and ensure that the proper tissue distribution is achieved in clinical practice. We developed a noninvasive imaging system based on the expression of artificial antibody receptors to trap hapten-labeled imaging probes. Functional membrane-bound anti-dansyl antibodies (DNS receptor) were stably expressed on melanoma cells in vitro and in vivo. A bivalent (DNS)2-diethylenetriaminepentaacetic 111Indium probe specifically bound to cells that expressed DNS receptors but not control scFv receptors. Importantly, the 111In probe preferentially localized to DNS receptors but not control receptors on tumors in mice as assessed by gamma camera imaging. By 48 h after intravenous injection, the uptake of the probe in tumors expressing DNS receptors was 72 times greater than the amount of probe in the blood. This targeting strategy may allow noninvasive assessment of the location, extent and persistence of gene expression in living animals and in the clinic.

N-phosphoryl amino acids and biomolecular origins

The possible role of phosphoryl amino acids for biomolecular origins is briefly reviewed. Peptide formation, ester formation, ester exchange on phosphorus and N to O migration occurred when the N-phosphoryl amino acid was incubated at room temperature. Short nucleotides and peptides were formed when nucleoside was reacted with N-phosphoryl amino acid at room temperature. Serine and threonine residues in their conjugate with different nucleosides (mediated with phosphorus) showed different self-cleavage activities. N-phosphoryl Histine and Ser-His dipeptide could cleave nucleic acids, proteins and esters in neutral medium. Based on a simple model, a pathway of 'co-evolution of protein and nucleic acid' was proposed.

Estradiol alters transcription factor gene expression in primate prefrontal cortex

Estrogen protects neurons from a variety of experimental insults in vitro, and is thought to protect from acute and chronic neurodegenerative processes in vivo. Estrogen also enhances higher-level cognitive functions that are centered in the dorsolateral prefrontal cortex (DLPFC) in human and non-human primates. To investigate genomic mechanisms involved in estrogenic effects on the primate brain in vivo, we compared transcription factor mRNA and protein expression in the DLPFC of ovariectomized rhesus monkeys treated with either vehicle or estradiol (E2). c-FOS, E2F1, and general transcription factor IIB (TFIIB) mRNA and protein expression were altered significantly by short-term E2 treatment, as shown by DNA array, in situ hybridization, and immunohistochemical and immunoblot evaluations. C-FOS expression was increased significantly whereas E2F1 and TFIIB levels were decreased in the DLPFC of E2-treated animals. These transcription factors were concentrated in cortical pyramids, as were estrogen receptors alpha and beta. These data indicate that estrogen may have direct as well as indirect effects on neuronal gene expression in the primate prefrontal cortex.

Evidence supporting dual, IGF-I-independent and IGF-I-dependent, roles for GH in promoting longitudinal bone growth

The possibility that growth hormone (GH) has effects on long bone growth independent of insulin-like growth factor-I (IGF-I) has long been debated. If this is true, then long bone growth should be more profoundly affected by the absence of GH (since both GH and GH-stimulated IGF-I effects are absent) than by the absence of IGF-I alone (since GH is still present and actually elevated). To test this hypothesis, we compared long bone growth in mice with targeted deletions of Igf1 vs growth hormone receptor (Ghr). Tibial linear growth rate was reduced by approximately 35% in Igf1 null mice and by about 65% in Ghr null mice between postnatal days 20 and 40, a time of peak GH effect during normal longitudinal growth. The Igf1 null mouse growth plate demonstrated significant enlargement of the germinal zone; chondrocyte proliferation and numbers were normal but chondrocyte hypertrophy was significantly reduced. In contrast, the Ghr null mouse germinal zone was hypoplastic, chondrocyte proliferation and numbers were significantly reduced, and chondrocyte hypertrophy was also reduced. We have previously demonstrated that IGF-II is highly expressed in growth plate germinal and proliferative zones, so we considered the possibility that GH-stimulated IGF-II production might promote germinal zone expansion and maintain normal proliferation in the Igf1 null mouse growth plate. Supporting this view, IGF-II mRNA was increased in the Igf1 null mouse and decreased in the Ghr null mouse growth plate.Thus, in the complete absence of IGF-I but in the presence of elevated GH in the Igf1 null mouse, reduction in chondrocyte hypertrophy appears to be the major defect in longitudinal bone growth. In the complete absence of a GH effect in the Ghr null mouse, however, both chondrocyte generation and hypertrophy are compromised, leading to a compound deficit in long bone growth. These observations support dual roles for GH in promoting longitudinal bone growth: an IGF-I-independent role in growth plate chondrocyte generation and an IGF-I-dependent role in promoting chondrocyte hypertrophy. The question of whether GH has direct effects on chondrocyte generation is still not settled, however, since it now appears that IGF-II may medicate some of these effects on the growth plate.

High-level expression of Dok-1 in neurons of the primate prefrontal cortex and hippocampus

The docking protein p62Dok-1 (Dok-1) has a central role in cell signaling mediated by a wide range of protein tyrosine kinases, including intrinsic membrane kinases, such as the insulin-like growth factor-1 (IGF-1) receptor. To elucidate potential IGF signaling mechanisms, we used DNA array technology to investigate novel kinase targets expressed in the primate dorsolateral prefrontal cortex (DLPFC). Dok-1 transcripts were among the most abundant found in this structure. Because Dok-1 expression has not been characterized in brain, we evaluated its expression pattern using immunoblotting, in situ hybridization, and immunohistochemistry in the rhesus monkey prefrontal cortex and hippocampal formation. Dok-1 antibodies identified a 62-kDa band in lysates from the DLPFC, consistent with the known size for Dok-1. In situ hybridization showed that Dok-1 mRNA was expressed in all layers of the DLPFC and in all neuronal subregions of the hippocampal formation. Immunohistochemical analysis showed Dok-1 immunoreactivity concentrated in pyramidal neurons of cortical layers IV-V and throughout Ammon's horn and in granule neurons of the dentate gyrus. Dok-1 expression was also identified in endothelial cells of cerebral blood vessels. These expression patterns are very similar to those of the IGF-1 receptor and suggest that Dok-1 could be among the downstream targets of IGF signaling in areas of the primate brain involved in learning and memory.

Endogenous IGF1 enhances cell survival in the postnatal dentate gyrus

The dentate gyrus is selectively reduced in size in the insulin-like growth factor 1 (IGF1) null mouse brain. The purpose of this study was to determine whether this defect is due to reduced granule cell numbers, and if so, to determine whether altered cell proliferation, survival, or both contribute to attenuation of dentate gyrus size. At postnatal day 10 (P10), granule cell numbers were not significantly different in IGF1 null and littermate wildtype (WT) dentate gyri. The subgranular zone cell population, however, was relatively increased, and the granule cell layer population relatively decreased in the IGF1 null dentate gyrus. By P50, total dentate cell numbers were decreased by 20% (P = 0.01) in the IGF1 null mouse, although IGF1 null subgranular zone progenitor cells remained relatively increased compared with WT (38%, P < 0.05). IGF1 null dentate cell proliferation, assessed by thymidine analogue incorporation, was actually increased at P10 (33%, P < 0.05) and P50 (167%, P = 0.001). Dentate granule cell death, assessed by the appearance of pycnotic cells and DNA fragmentation, was also significantly increased in the IGF1 null dentate (61%, P < 0.05 and 101%, P = 0.03). These data suggest that endogenous IGF1 serves an important role in dentate granule cell survival during the course of postnatal brain development. In addition, this work suggests the potential of a compensatory mechanism promoting increased dentate cell proliferation in the face of impaired cell survival during postnatal neurogenesis. J. Neurosci. Res. 64:341-347, 2001. Published 2001 Wiley-Liss, Inc.

Estrogen augments glucose transporter and IGF1 expression in primate cerebral cortex

Estrogen has many positive effects on neural tissue in experimental model systems, including stimulation of neurite growth and neurotransmitter synthesis and protection against diverse types of neural injury. In humans, estrogen treatment is reputed to protect against Alzheimer's disease. To investigate potential mediators of estrogen's action and determine whether selective estrogen receptor modulators (SERMs) such as tamoxifen have estrogen-like effects in the primate brain, we evaluated the expression of glucose transporters and insulin-like growth factor 1 (IGF1) and its receptor in the frontal cortex of ovariectomized rhesus monkeys. We treated one group for 3 days with vehicle, another with 17 beta estradiol (E2), and a third with tamoxifen. The expression of facilitative glucose transporters (Gluts) 1, 3, and 4 was investigated using in situ hybridization, immunohistochemistry, and immunoblot analysis. Gluts 3 and 4 were concentrated in cortical neurons and Glut1 in capillaries and glial cells. E2 treatment induced two- to fourfold increases in Glut3 and Glut4 mRNA levels and lesser but significant increases in Glut3 and 4 protein levels. E2 treatment induced an approximately 70% increase in parenchymal Glut1 mRNA levels, but did not appreciably affect vascular Glut1 gene expression. IGF1 and IGF1 receptor mRNAs were concentrated in cortical neurons in a distribution similar to Gluts 3 and 4. IGF1 mRNA levels were significantly increased in E2-treated animals but IGF1 receptor mRNA levels were not altered by hormone treatment. Tamoxifen increased cerebral cortical Glut3 and 4 mRNA levels, but did not affect Glut1, IGF1, or IGF1 receptor expression. This study provides novel data showing that Gluts 3 and 4 and IGF1 are coexpressed by primate cerebral cortical neurons, where their expression is enhanced by estrogen. These findings suggest that up-regulation of glucose transporter and IGF1 expression may contribute to estrogen's salutary effects on neural tissue. Tamoxifen, an antiestrogen at the breast, is shown to have estrogen-like effects on higher brain centers in the monkey, suggesting that some SERMs may share estrogen's neuroprotective potential for menopausal women.

Medicare physician payment changes: impact on physicians and beneficiaries

The Balanced Budget Act (BBA) of 1997 generally reduced Medicare payments for surgical services while increasing them for other services. Concern about implications of these fee reductions prompted the Medicare Payment Advisory Commission to sponsor a national survey of physicians to learn their views on Medicare payment and whether access to care has changed for Medicare beneficiaries. Results suggest that beneficiaries' access to care has not declined. While physicians are concerned about Medicare reimbursement, they are more concerned about reimbursement from managed care plans and Medicaid. Continued monitoring will be important to detect any emerging access problems accompanying upcoming payment reductions.

Insulin-like growth factor 1 regulates developing brain glucose metabolism

The brain has enormous anabolic needs during early postnatal development. This study presents multiple lines of evidence showing that endogenous brain insulin-like growth factor 1 (Igf1) serves an essential, insulin-like role in promoting neuronal glucose utilization and growth during this period. Brain 2-deoxy-d- [1-(14)C]glucose uptake parallels Igf1 expression in wild-type mice and is profoundly reduced in Igf1-/- mice, particularly in those structures where Igf1 is normally most highly expressed. 2-Deoxy-d- [1-(14)C]glucose is significantly reduced in synaptosomes prepared from Igf1-/- brains, and the deficit is corrected by inclusion of Igf1 in the incubation medium. The serine/threonine kinase Akt/PKB is a major target of insulin-signaling in the regulation of glucose transport via the facilitative glucose transporter (GLUT4) and glycogen synthesis in peripheral tissues. Phosphorylation of Akt and GLUT4 expression are reduced in Igf1-/- neurons. Phosphorylation of glycogen synthase kinase 3beta and glycogen accumulation also are reduced in Igf1-/- neurons. These data support the hypothesis that endogenous brain Igf1 serves an anabolic, insulin-like role in developing brain metabolism.

Over-the-counter hearing aids: electroacoustic characteristics and possible target client groups

Over-the-counter hearing aids (OTCs) are those directly purchased from retail outlets, without the benefit of prior professional hearing health care. They are particularly common in developing countries. This study examined the amplification characteristics of a selected sample of OTCs to determine if any target client group or groups were suitable for the OTCs. The electroacoustical performance of 10 OTCs was measured. The measurements included saturated sound pressure level curve, high-frequency average full-on gain, frequency response, total harmonic distortion, equivalent input noise level, and input-output curve. The full-on gain curve of each hearing aid was used to estimate the hypothetical hearing loss of target clients for each aid as it would be calculated by four hearing aid prescription formulae. Real-ear probe tube measurements were also performed on 10 adult subjects to determine the amplification that could be achieved by the OTCs before audible feedback occurred. The OTC hearing aids were not able to meet the prescription gain requirements of the majority of elderly clients who usually purchased them.

Role of rpoS in acid resistance and fecal shedding of Escherichia coli O157:H7

Acid resistance (AR) is important to survival of Escherichia coli O157:H7 in acidic foods and may play a role during passage through the bovine host. In this study, we examined the role in AR of the rpoS-encoded global stress response regulator sigma(S) and its effect on shedding of E. coli O157:H7 in mice and calves. When assayed for each of the three AR systems identified in E. coli, an rpoS mutant (rpoS::pRR10) of E. coli O157:H7 lacked the glucose-repressed system and possessed reduced levels of both the arginine- and glutamate-dependent AR systems. After administration of the rpoS mutant and the wild-type strain (ATCC 43895) to ICR mice at doses ranging from 10(1) to 10(4) CFU, we found the wild-type strain in feces of mice given lower doses (10(2) versus 10(3) CFU) and at a greater frequency (80% versus 13%) than the mutant strain. The reduction in passage of the rpoS mutant was due to decreased AR, as administration of the mutant in 0.05 M phosphate buffer facilitated passage and increased the frequency of recovery in feces from 27 to 67% at a dose of 10(4) CFU. Enumeration of E. coli O157:H7 in feces from calves inoculated with an equal mixture of the wild-type strain and the rpoS mutant demonstrated shedding of the mutant to be 10- to 100-fold lower than wild-type numbers. This difference in shedding between the wild-type strain and the rpoS mutant was statistically significant (P </= 0.05). Thus, sigma(S) appears to play a role in E. coli O157:H7 passage in mice and shedding from calves, possibly by inducing expression of the glucose-repressed RpoS-dependent AR determinant and thus increasing resistance to gastrointestinal stress. These findings may provide clues for future efforts aimed at reducing or eliminating this pathogen from cattle herds.

Contents of constituents in mature and immature fruits of evodia species

A total of 33 commercial samples of Evodiae fructus originated from the rutaceous plants Evodia rutaecarpa (Juss.) Benth. and E. rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang (= E. officinalis Dode), respectively, were collected from Taiwan's herbal market. The contents of eighteen constituents (including 15 alkaloids, 2 flavonoids and 1 diterpenoid) in these samples were determined by high-performance liquid chromatography within 60 minutes. Analysis results showed that the constituent contents were almost unrelated to the species, but rather closely related to the degrees of maturity of the fruit. Those fruits with open mouths and unsplit ovaries had the highest total contents, fruits with open mouths and split ovaries had lower contents, and fruits with closed mouths had the lowest contents. In terms of the individual constituents, the open-mouth fruits contained higher contents of dehydroevodiamine, evodiamine, evocarpine and rutaecarpine, whereas the closed-mouth fruits had higher contents of dehydroevodiamine, epimedoside C, evocarpine and evodiamine.

Do hospital-based rural health clinics improve the performance of the parent hospital?

This study shows that establishing an RHC may lead to beneficial impacts for the parent hospital, and that these benefits have been experienced by categories of hospitals that are now subject to the new limit on RHC reimbursement legislated by the Balanced Budget Act.

The primary immunity determinant in modulating the lysogenic immunity of the filamentous bacteriophage cf

Bacteriophage cf is the first single-stranded DNA phage that has been shown to set up a stable lysogenic state with its genome integrated into the host chromosome. From the isolation and characterization of a virulent mutant, cf-tv2, we report the first investigation into the mechanisms of the immunity established by the filamentous bacteriophage. The mutation in cf-tv2 enables the phage to produce plaques on lawns of cf lysogenic cells. The mutation was defined as a 49-nucleotide deletion located in a 0.59 kb NcoI/KpnI fragment of cf replicative form DNA. Two messages, cM1 and cM2, transcribed from the immunity region of wild-type cf but in opposite directions, were detected. In cf-tv2, the 49-nucleotide deletion abolishes cM2 transcription. The primer extension assay suggests a possible RNA-RNA interaction directed by base-pairing of the cM1 and cM2 RNAs. A frameshift mutation of the open reading frame ORF 165, encoded by cM2, resulted in a 10(5) plating efficiency on the cf lysogen. These observations suggest that both RNA-RNA interaction and repressor protein inhibition are involved in the mechanism of cf immunity. A model is proposed for the regulation of cf immunity.

Transcription of the genome of the filamentous bacteriophage cf from both plus and minus DNA strands

The filamentous bacteriophage cf infects the bacterium Xanthomonas campestris pv. citri. Northern blot analysis with probes derived from various restriction fragments of cf replicative form (RF) DNA has revealed the presence of five major phage-specific transcripts in infected cells. Four of these transcripts were shown to be derived from the region of the cf genome extending from gene II to gene VIII and are consistent with the cascade model of transcription proposed for Ff coliphages. These transcripts overlap with each other and terminate upstream of an efficient Rho-independent transcription terminator. Unlike the well-characterized Ff phages, in which only the minus strand of viral DNA serves as a transcription template, both strands of the RF DNA of phage cf appeared to be transcribed. Thus one of the five major cf transcripts was shown to be derived from a region of the viral minus strand that contains an open reading frame encoding a putative polypeptide of 165 amino acids. Primer extension analysis mapped the transcriptional initiation site of this RNA to a cytosine residue at position 870. A partial transcription map of phage cf revealed two independent regions of transcriptional activity. The region with the highest activity coincides with that encoding the polypeptides required in the largest amounts during the cf infection cycle.

Color image processing by using binary quaternion-moment-preserving thresholding technique

This paper presents a new moment-preserving thresholding technique, called the binary quaternion-moment-preserving (BQMP) thresholding, for color image data. Based on representing color data by the quaternions, the statistical parameters of color data can be expressed through the definition of quaternion moments. Analytical formulas of the BQMP thresholding can thus be determined by using the algebra of the quaternions. The computation time for the BQMP thresholding is of order of the data size. By using the BQMP thresholding, quaternion-moment-based operators are designed for the application of color image processing, such as color image compression, multiclass clustering of color data, and subpixel color edge detection. The experimental results show that the proposed operator for color image compression can have output picture quality acceptable to human eyes. In addition, the proposed edge operator can detect the color edge at the subpixel level. Therefore, the proposed BQMP thresholding can be used as a tool for color image processing.

Vulnerability of rural hospitals to Medicare outpatient payment reform

Because the Balanced Budget Act (BBA) of 1997 requires implementation of a Medicare prospective payment system (PPS) for hospital outpatient services, the authors evaluated the potential impact of outpatient PPS on rural hospitals. Areas examined include: (1) How dependent are rural hospitals on outpatient revenue? (2) Are they more likely than urban hospitals to be vulnerable to payment reform? (3) What types of rural hospitals will be most vulnerable to reform? Using Medicare cost report data, the authors found that small size and government ownership are more common among rural than urban hospitals and are the most important determinants of vulnerability to payment reform.

Biochemical and morphometric analyses show that myelination in the insulin-like growth factor 1 null brain is proportionate to its neuronal composition

To elucidate the role of insulin-like growth factor 1 (IGF1) in the normal development of brain myelination, we used behavioral, biochemical, and histological analyses to compare the myelination of brains from Igf1(-/-) and wild-type (WT) littermate mice. The studies were conducted at postnatal day 40, at which time the Igf1(-/-) mice weighed approximately 66% less than wild-type mice. However, the Igf1(-/-) brain weight was only reduced by approximately 34%. Formal neurological testing showed no sign of central or peripheral myelinopathy in Igf1(-/-) mice. Myelin composition was not significantly different, and myelin concentration, normalized to brain weight or protein, was equal in Igf1(-/-) and WT mice. Likewise, concentrations of myelin-specific proteins (MBP, myelin proteolipid protein, MAG, and 2',3'-cyclic nucleotide,3'-phosphodiesterase) were not significantly different in Igf1(-/-) and WT mice. The myelin-associated lipids galactocerebroside and sulfatide were modestly reduced in Igf1(-/-) brains. Regional oligodendrocyte populations and myelin staining patterns were comparable in Igf1(-/-) and WT brains, with the notable exception of the olfactory system. The Igf1(-/-) olfactory bulb was profoundly reduced in size and was depleted of mitral neurons and oligodendrocytes, and its efferent tracts were depleted of myelin. In summary, this study shows that myelination of the Igf1(-/-) brain is proportionate to its neuronal composition. Where projection neurons are preserved despite the deletion of IGF1, as in the cerebellar system, oligodendrocytes and myelination are indistinguishable from wild type. Where projection neurons are depleted, as in the olfactory bulb, oligodendrocytes are also depleted, and myelination is reduced in proportion to the reduced projection neuron mass. These data make a strong case for the primacy of axonal factors, not including IGF1, in determining oligodendrocyte survival and myelination.

Initiation and maintenance of a hospital-based parent group for parents of premature infants: key factors for success

The impact of a premature birth can be very traumatic for parents. They are usually not prepared for this event, and their sense of grief and loss is so intense that they often have difficulty coping with the situation. A parent group can help parents adapt to the crisis of prematurity by providing information and family support. This article describes the development of a parent group at a regional perinatal center in Ontario and identifies key factors for its successful initiation and maintenance.

Sequence of a human E2F-4 pseudogene with shortened AGC trinucleotide repeats

We have isolated a human genomic DNA fragment of 0.7 kb by polymerase chain reaction (PCR) using human E2F-4 gene primers. Sequence analysis indicates that this DNA comes from a processed E2F-4 pseudogene. Its sequence is 75% identical to the human E2F-4 cDNA, and bears several deletions and insertions. A 30 bp deletion shortens the 13 AGC repeats in the E2F-4 gene by 10 repeats. The sequence data also suggest that another 65 bp deletion and some small insertions may be generated by replication errors on template pairing.

Assessment of reliability and validity of the behavioral observation record for developmental care

Due to time constraints, clinicians are rarely able to carry out neurobehavioral assessments that use the Naturalistic Observation of Newborn Behavior Instrument. The content validity, interrater reliability, and criterion-related validity for a less time-consuming instrument, the Modified Infant Behavioral Observation Record (MIBOR) for developmental care was evaluated in this study. Eight developmental care specialists evaluated the MIBOR for content validity. Fifteen infants (birth weight < 1,500 g) were observed to determine interrater reliability, and three were observed to evaluate criterion-related validity. The content validity of the MIBOR, as determined by average congruence, was 96.9%. Interrater reliability for each developmental care subsystem ranged from 67% to 98%. Three of the four subsystems on the MIBOR achieved criterion-related validity, achieving an agreement of r = .60.

Single-stranded DNA binding protein from bacteriophage cf: characterization, gene localization and protein-ssDNA complex

The single-stranded DNA binding protein from the filamentous bacteriophage cf has been purified and characterized. The first 12 amino acids, resulting from the N-terminal amino acid sequencing analysis of the protein, agree with an open reading frame (ORF) on the cf genome. The ORF contains 294 bp and codes for a 98 a.a. protein of molecular weight 10.8 kDa, consistent with the result from the denaturing protein gel analysis. The protein appears to be a homodimer as evident from the apparent molecular weight of about 22 kDa obtained from native protein gel analysis. The gene location of the protein has been identified as gene V of the cf single stranded genome, same as that from the M13 phage. The GVP of cf shows a strong sequence homology to the ssDNA binding proteins of Ff, IKe and Pf3 filamentous phages. The DNA binding wing of GVP, conserved among the filamentous phages, has been predicted for cf. To further characterize the protein, the GVP-ssDNA complex of cf has been purified from the infected host (Xanthomonas campestris pv. citri) by density gradient centrifugation. Transmission electron microscopy (TEM) images of the complex showed that it is about 1200 nm in length and 9 nm in diameter and it has a highly regular morphology with a central groove shadow running along the entire structure, but without any apparent helical pattern seen in the M13 complex. The GVP-ssDNA complex of cf seems more rigid than that of M13. Our computer modeling study suggested that this difference between the two complexes may be due to the additional 11 or 12 amino acids at the C-terminal end of the cf-GVP.

Rifampicin: an inhibitor of Xp12-specific protein phosphorylation in Xanthomonas oryzae pv. oryzae

Phosphorylation of the three Xp12-specific phosphoproteins was drastically reduced by rifampicin, an antibiotic that specifically inhibits the host-cell RNA polymerase. However, this inhibitory effect could not be found in spontaneous mutants of Xanthomonas oryzae pv. oryzae whose RNA polymerase are resistant to the drug. The inhibitory effect of rifampicin treatment also resulted suppression of the Xp12 multiplication cycle. This implies the physiological significance of this effect and supports our previous prediction that phosphorylation plays an important role in the life cycle of Xp12. The acid- and alkali-labile character of the Xp12-specific phosphoproteins and the chemical stability of the phosphoryl linkages show that the corresponding protein kinase catalyzes the formation of an acyl phosphorylation. Subsequent fractionation of cell lysate revealed that the phosphoproteins were located in the periplasm. Actinomycin D, which affects transcription through DNA condensation rather than its binding to RNA polymerase, was not able to cause the inhibition effect. On the other hand, cerulenin was found to reduce the acyl phosphorylation which hints at a possible role of cell membrane in the phosphorylation. Here we present the evidence for the functional involvement of the rifampicin treatment on protein phosphorylation. A possible mechanism of rifampicin on the alternation of acyl phosphorylation is proposed.

rpoS regulation of acid, heat, and salt tolerance in Escherichia coli O157:H7

An rpoS mutant (rpoS::pRR10) of Escherichia coli O157:H7 ATCC 43895 was generated. Stationary-phase acid, heat, and salt tolerance was significantly reduced, and starvation-induced acid tolerance did not develop in the mutant. RpoS was also important for survival of E. coli O157:H7 in dry, fermented sausage.

Rapid inhibition of protein histidine phosphorylation by UV-irradiation in Xanthomonas oryzae pv. oryzae

Exposure of Xanthomonas oryzae pv. oryzae cells to 254 nm UV radiation resulted in an alteration of protein phosphorylation. Labelling of the phosphohistidine-containing proteins with molecular masses of 81 and 32 kDa, named p81 and p32, was rapidly reduced following UV irradiation in the early exponential cells, but the decrease was not detected in mid-exponential cells. Mitomycin C, a DNA replication inhibitor, and rifampicin, a drug generally used to inhibit RNA synthesis and DNA replication, were also found to reduce the histidyl phosphorylation. However, this alteration of protein phosphorylation was not hindered by chloramphenicol treatment. A possible role for these histidyl phosphoproteins in sensing UV light is proposed.

Synergism of GH and IGF-I in stimulation of sulphate uptake by teleostean branchial cartilage in vitro

The combined effects of teleostean GH and human IGF-I in the regulation of teleost branchial cartilage growth were examined. Ceratobranchial cartilages were dissected from the common carp (Cyprinus carpio) and maintained in a defined culture medium supplemented with recombinant striped bass GH (sbGH), human IFG-I (hIGF-I) or both, and the uptake of [35S]sulphate by cartilage explants was measured. sbGH alone in the culture medium did not exhibit a significant stimulatory effect on the uptake of [35S]sulphate when compared with the controls. However, with hIGF-I in the culture medium, as low as 1 ng/ml, the stimulatory effect of sbGH was apparent and dose-dependent. The synergism of sbGH and hIGF-I was observed at the concentrations of 1 and 10 ng IGF-I/ml tested. At a constant hIGF-I concentration (10 ng/ml), a maximum stimulatory effect was detected with 3 micrograms recombinant sbGH/ml, at which point a 2.3-fold increase in sulphation activity was obtained when compared with the treatment with hIGF-I alone. A similar dose-dependent stimulatory effect was observed when native common carp and bonito GHs were tested using this assay system. These results suggest that the synergistic effect of sbGH and hIGF-I on sulphation activity is a common biological function of teleost GH, thus ruling out the possibility of experimental artifacts resulting from utilization of heterologous GH. Furthermore, experiments were conducted to test whether the synergism between sbGH and hIGF-I occurred between sbGH and insulin.(ABSTRACT TRUNCATED AT 250 WORDS)

Appearance of insulin-like growth factor mRNA in the liver and pyloric ceca of a teleost in response to exogenous growth hormone

Augmentation of vertebrate growth by growth hormone (GH) is primarily due to its regulation of insulin-like growth factor I (IGF I) and IGF II levels. To characterize the effect of GH on the levels of IGF I and IGF II mRNA in a teleost, 10 micrograms of bovine GH (bGH) per g of body weight was administered to juvenile rainbow trout (Oncorhynchus mykiss) through i.p. injection. The levels of IGF I and IGF II mRNA were determined simultaneously, by using RNase protection assays, in the liver, pyloric ceca, kidney, and gill at 0, 1, 3, 6, 12, 24, 48, and 72 hr after injection. In the liver, IGF I mRNA levels were significantly elevated at 6 and 12 hr (approximately 2- to 3-fold, P < or = 0.01), while IGF II mRNA levels were significantly elevated at 3 and 6 hr (approximately 3-fold, P < or = 0.01). In the pyloric ceca, IGF II mRNA levels were significantly elevated at 12, 24, and 48 hr (approximately 3-fold, P < or = 0.01), while IGF I mRNA was below the limits of assay accuracy. GH-dependent IGF mRNA appearance was not detected in the gill and kidney. Serum bGH levels, determined by using a radioimmunoassay, were significantly elevated at 3 and 6 hr (P < 0.005). In primary hepatocyte culture, IGF I and IGF II mRNA levels increased in a bGH dose-dependent fashion, with ED50 values of approximately 45 and approximately 6 ng of bGH per ml, respectively. The GH-dependent appearance of IGF II mRNA in the liver and pyloric ceca suggests important roles for this peptide hormone exclusive of IGF I.

Production of a biologically active recombinant teleostean growth hormone in E. coli cells

We have isolated and characterized several recombinant lambda phage clones carrying growth hormone (GH) cDNA of striped bass (Morone saxatilis). Nucleotide sequence and the predicted amino acid sequence of sbGH was determined from a recombinant clone carrying the longest cDNA insert. The sbGH cDNA encodes a pre-hormone of 204 amino acid residues. Comparison of the predicted amino acid sequence of sbGH with those of other vertebrates revealed different degrees of sequence identity: approximately 98% with European sea bass; 90% with bluefin tuna; bonito and red seabream; 71% with winter flounder; 64% with salmonids; 55% with carp; and 38% with human. Expression of the mature sbGH cDNA (without the signal peptide sequence) in E. coli cells under regulation of the lambda phage PL promoter produced a polypeptide of 20 kDa. Following renaturation, this recombinant hormone was shown to be biologically active in a radioreceptor competition binding assay and in the induction of hepatic insulin-like growth factor I (IGF-I) mRNA synthesis in vivo.

Specific protein phosphorylation induced in Xanthomonas campestris pv. oryzae by bacteriophage Xp12

We have investigated the endogenous phosphorylation patterns of phosphorylated proteins of Xanthomonas campestris pv. oryzae induced by its bacteriophages. For bacteriophage Xp12-infected cells, at least three phosphoproteins with apparent molecular weights of 28, 28.5 and 45 kDa were detected by in vitro labeling with [gamma-32P]-ATP. These Xp12-specific phosphoproteins only occurred with Xp12 infection, and were not shown in uninfected or Xp10-infected cells. The protein kinase(s) responsible could use either ATP or GTP as the nucleotide substrate with nearly the same efficiency. Magnesium was proved to be an essential factor for the phosphorylation. EGTA treatment excluding the possibility that the presumed protein kinase was calcium-dependent. Under our reaction conditions, the optimal phosphorylation occurred at pH 7 to 8, for 30 to 40 min at 25 to 37 degrees C. The Xp12-specific protein phosphorylation hint the existence of a physiological regulation mechanism involved in the life cycle of bacteriophage Xp12. Furthermore, the presumed protein kinase was shown to be encoded by the genome of Xp12 rather than indirectly induced by Xp12 infection.

Antitumor agents, 145. Cytotoxic asprellic acids A and C and asprellic acid B. new p-coumaroyl triterpenes, from Ilex asprella

Three new p-coumaroyl triterpenes, asprellic acids A [1], B [2], and C [3], were isolated from the EtOH extract of dried leaves of Ilex asprella. The structures for 1-3 have been established as 3,27-di-O-trans-p-coumaroyl [1], 3-O-trans-p-coumaroyl-27-O-cis-p-coumaroyl- [2], and 3-O-cis-p-coumaroyl-27-O-trans-p-coumaroyl- [3] 3 beta,27-dihydroxyolean-12-en-28-oic acid, respectively, by spectral and chemical examinations. Asprellic acid A [1] exhibited potent cytotoxicity against the RPMI-7951 cell line with an ED50 value of 0.62 micrograms/ml, while the cytotoxicity of asprellic acid C [3] against RPMI-7951 was marginal (ED50 5.5 micrograms/ml). Compounds 1 and 3 also showed cytotoxicity against KB cells with ED50 values of 3.75 and 2.86 micrograms/ml, respectively. Asprellic acid B [2] did not show cytotoxicity (> 10 micrograms/ml) against KB or RPMI-7951 cell lines.