SCP1 regulates c-Myc stability and functions through dephosphorylating c-Myc Ser62

Serine 62 (Ser62) phosphorylation affects the c-Myc protein stability in cancer cells. However, the mechanism for dephosphorylating c-Myc is not well understood. In this study, we identified carboxyl-terminal domain RNA polymerase II polypeptide A small phosphatase 1 (SCP1) as a novel phosphatase specifically dephosphorylating c-Myc Ser62. Ectopically expressed SCP1 strongly dephosphorylated c-Myc Ser62, destabilized c-Myc protein and suppressed c-Myc transcriptional activity. Knockdown of SCP1 increased the c-Myc protein levels in liver cancer cells. SCP1 interacted with c-Myc both in vivo and in vitro. In addition, Ser245 at the C-terminus of SCP1 was essential for its phosphatase activity towards c-Myc. Functionally, SCP1 negatively regulated the cancer cell proliferation. Collectively, our findings indicate that SCP1 is a potential tumor suppressor for liver cancers through dephosphorylating c-Myc Ser62.

Gallstone recurrence after minimally-invasive cholecystolithotomy with gallbladder reservation: a follow-up of 720 cases

OBJECTIVE

To discuss the hazards of cholecystolithiasis recrudesce after cholecystolithotomy with gallbladder reservation; To provide a theoretical basis for reducing the recurrence rate of gallstone.

PATIENTS AND METHODS

The patients who were followed up for at least one year after minimally-invasive operation with gallbladder reservation because of cholecystolithiasis were selected. In this population, the patients with recurrence after surgery were as the case group, those patients with no recurrence after surgery were as the control group. Through collection of general data of selected cases, relevant information of Ultrasound Examinations of gallbladder and history data of the patients questionnaires were completed. Relevant factors of gallstone recurrence of patients, were observed through statistic analysis. Main factors go as follows: gender, age, nation, career, BMI, whether or not the patient had the history of chronic superficial gastritis, and regulation of gallbladder emptying function, family history, etc. The information of selected cases is complete.

RESULTS AND CONCLUSIONS

The main hazards of cholecystolithiasis recurrence were BMI, family history of gallstone disease, and emptying function of gallbladder.

Anomalous self-reduction of layered double hydroxide (LDH): from α-Ni(OH)2 to hexagonal close packing (HCP) Ni/NiO by annealing without a reductant

An anomalous self-reduction phenomenon can occur for Ni LDH synthesized from an ionic liquid system.

Role of the RUNX2 p.R225Q mutation in cleidocranial dysplasia: a rare presentation and an analysis of the RUNX2 protein structure

Cleidocranial dysplasia (CCD; MIM 119600) is an autosomal dominant hereditary disorder of skeletal features whose characteristic clinical symptoms are caused by mutations in the RUNX2 gene. Varying degrees of clavicular hypoplasia and dental abnormalities are the most prominent features of this disorder. In this study, we presented a Chinese family that included 4 individuals with a p.R225Q mutation in the RUNX2 gene and characteristic CCD phenotypes. Through structural analysis of the p.R225Q mutation in the RUNX2 protein, we determined that the location of this mutation has the potential to affect DNA binding by RUNX2. The proband in this CCD-affected family showed a specific clinical phenotype of CCD that included a median pseudo-cleft palate, which is a presentation of this mutation that has not been reported previously. On the basis of the structural analysis, this study further demonstrated that the p.R225Q mutation abolished DNA binding by RUNX2 and its results also suggested that other genetic and/or environmental factors could affect the CCD phenotypes.

MEAT SCIENCE AND MUSCLE BIOLOGY SYMPOSIUM--mechanism of growth hormone stimulation of skeletal muscle growth in cattle

Growth hormone, also called somatotropin (ST), is a polypeptide hormone produced by the anterior pituitary. The major functions of GH include stimulating bone and skeletal muscle growth, lipolysis, milk production, and expression of the IGF-I gene in the liver. Based on these functions, recombinant bovine ST (bST) and recombinant porcine ST (pST) have been used to improve milk production in dairy cows and lean tissue growth in pigs, respectively. However, despite these applications, the mechanisms of action of GH are not fully understood. Indeed, there has been a lot of controversy over the role of liver-derived circulating IGF-I and locally produced IGF-I in mediating the growth-stimulatory effect of GH during the last 15 yr. It is in this context that we have conducted studies to further understand how GH stimulates skeletal muscle growth in cattle. Our results do not support a role of skeletal muscle-derived IGF-I in GH-stimulated skeletal muscle growth in cattle. Our results indicate that GH stimulates skeletal muscle growth in cattle, in part, by stimulating protein synthesis in muscle through a GH receptor-mediated, IGF-I-independent mechanism. In this review, besides discussing these results, we also argue that liver-derived circulating IGF-I should be still considered as the major mechanism that mediates the growth-stimulatory effect of GH on skeletal muscle in cattle and other domestic animals.

Impact of wave front and coherence optimization in coherent diffractive imaging

We present single shot nanoscale imaging using a table-top femtosecond soft X-ray laser harmonic source at a wavelength of 32 nm. We show that the phase retrieval process in coherent diffractive imaging critically depends on beam quality. Coherence and image fidelity are measured from single-shot coherent diffraction patterns of isolated nano-patterned slits. Impact of flux, wave front and coherence of the soft X-ray beam on the phase retrieval process and the image quality are discussed. After beam improvements, a final image reconstruction is presented with a spatial resolution of 78 nm (half period) in a single 20 fs laser harmonic shot.

Donor age-specific injury and immune responses

Utilization rates of organs from elderly donors have shown the highest proportional increase during the last decade. Clinical reports support the concept of transplanting older organs. However, the engraftment of such organs has been linked to accelerated immune responses based on ageing changes per se and a proinflammatory environment subsequent to compromised injury and repair mechanism. We analyzed the clinical consequences of transplanting older donor organs and present mechanistic aspects correlating age, injury repair and effects on host immunoresponsiveness.

Inhibition of myostatin protects against diet-induced obesity by enhancing fatty acid oxidation and promoting a brown adipose phenotype in mice

AIMS/HYPOTHESIS

Although myostatin-null (Mstn (-/-)) mice fail to accumulate fat in adipose tissue when fed a high-fat diet (HFD), little is known about the molecular mechanism(s) behind this phenomenon. We therefore sought to identify the signalling pathways through which myostatin regulates accumulation and/or utilisation of fat.

METHODS

Wild-type, Mstn (-/-) and wild-type mice treated with soluble activin type IIB receptor (sActRIIB) were fed a control chow diet or an HFD for 12 weeks. Changes in gene expression were measured by microarray and quantitative PCR. Histological changes in white adipose tissue were assessed together with peripheral tissue fatty acid oxidation and changes in circulating hormones following HFD feeding.

RESULTS

Our results demonstrate that inactivation of myostatin results in reduced fat accumulation in mice on an HFD. Molecular analysis revealed that metabolic benefits, due to lack of myostatin, are mediated through at least two independent mechanisms. First, lack of myostatin increased fatty acid oxidation in peripheral tissues through induction of enzymes involved in lipolysis and in fatty acid oxidation in mitochondria. Second, inactivation of myostatin also enhanced brown adipose formation in white adipose tissue of Mstn (-/-) mice. Consistent with the above, treatment of HFD-fed wild-type mice with the myostatin antagonist, sActRIIB, reduced the obesity phenotype.

CONCLUSIONS/INTERPRETATION

We conclude that absence of myostatin results in enhanced peripheral tissue fatty acid oxidation and increased thermogenesis, culminating in increased fat utilisation and reduced adipose tissue mass. Taken together, our data suggest that anti-myostatin therapeutics could be beneficial in alleviating obesity.

Growth hormone stimulates protein synthesis in bovine skeletal muscle cells without altering insulin-like growth factor-I mRNA expression

Growth hormone is a major stimulator of skeletal muscle growth in animals, including cattle. In this study, we determined whether GH stimulates skeletal muscle growth in cattle by direct stimulation of proliferation or fusion of myoblasts, by direct stimulation of protein synthesis, or by direct inhibition of protein degradation in myotubes. We also determined whether these direct effects of GH are mediated by IGF-I produced by myoblasts or myotubes. Satellite cells were isolated from cattle skeletal muscle and were allowed to proliferate as myoblasts or induced to fuse into myotubes in culture. Growth hormone at 10 and 100 ng/mL increased protein synthesis in myotubes (P < 0.05), but had no effect on protein degradation in myotubes or proliferation of myoblasts (P > 0.05). Insulin-like growth factor-I at 50 and 500 ng/mL stimulated protein synthesis (P < 0.01), and this effect of IGF-I was much greater than that of GH (P < 0.05). Besides stimulating protein synthesis, IGF-I at 50 and 500 ng/mL also inhibited protein degradation in myotubes (P < 0.01), and IGF-I at 500 ng/mL stimulated proliferation of myoblasts (P < 0.05). Neither GH nor IGF-I had effects on fusion of myoblasts into myotubes (P > 0.1). These data indicate that GH and IGF-I have largely different direct effects on bovine muscle cells. Growth hormone at 10 and 100 ng/mL had no effect on IGF-I mRNA expression in either myoblasts or myotubes (P > 0.1). This lack of effect was not because the cultured myoblasts or myotubes were not responsive to GH; GH receptor mRNA was detectable in them and the expression of the cytokine-inducible SH2-containing protein (CISH) gene, a well-established GH target gene, was increased by GH in bovine myoblasts (P < 0.05). Overall, the data suggest that GH stimulates skeletal muscle growth in cattle in part through stimulation of protein synthesis in the muscle and that this stimulation is not mediated through increased IGF-I mRNA expression in the muscle.

Identification and characterization of the cysteine protease inhibitor gene MdCPI from Musca domestica

Cysteine proteinase inhibitors (CPIs) are involved in many vital cellular processes such as signalling pathways, apoptosis, immune response and development; however, no CPIs have yet been reported from the housefly Musca domestica. Here we report the isolation and characterization of a housefly CPI gene designated MdCPI. The gene contains an open reading frame of 357 bp encoding a protein of 118 amino acid residues with a putative signal peptide of 17 amino acid residues. Protein alignment demonstrated a high homology to that of Sarcophaga crassipalpis (identity = 51%). Phylogenetic analysis suggested that all CPIs from dipterans, including the housefly, belong to the I25A family and may be descended from a single common ancestor. The gene was expressed in and purified from Escherichia coli. Biochemical studies showed that MdCPI exerts an inhibiting function on papain, which is a classical assay to confirm CPIs. Real-time quantitative PCR and immunolocalization analysis revealed that MdCPI is specifically expressed in haemocytes and fat bodies. It is highly down-regulated in larvae and markedly up-regulated in the pupal stage, suggesting that it may be related to development.

Myostatin-deficient mice exhibit reduced insulin resistance through activating the AMP-activated protein kinase signalling pathway

AIMS/HYPOTHESIS

Myostatin-null mice (Mstn(-/-)) have reduced body fat and increased tolerance to glucose. To date the molecular mechanisms through which myostatin regulates body fat content and insulin sensitivity are not known. Therefore, the aim of the current study was to identify signalling pathways through which myostatin regulates insulin sensitivity.

METHODS

Wild-type (WT) mice and Mstn(-/-) mice were fed either a control chow diet or a high fat diet (HFD) for 12 weeks. Glucose tolerance testing and insulin stimulated glucose uptake by M. extensor digitorum longus (EDL) were used as variables to determine insulin sensitivity. Quantitative PCR, Western blotting and enzyme assays were used to monitor AMP-activated protein kinase (AMPK) levels and activity.

RESULTS

Mstn(-/-) mice exhibited reduced fat accumulation and peripheral insulin resistance when compared with WT mice, even when they were fed an HFD. Furthermore, treatment with a myostatin antagonist also increased insulin sensitivity during HFD. Consistent with increased insulin sensitivity, we also detected elevated levels of GLUT4, AKT, p-AKT and insulin receptor substrate-1 in Mstn(-/-) muscles. Molecular analysis showed that there is increased expression and activity of AMPK in Mstn(-/-) muscles. Furthermore, we also observed an increase in the AMPK downstream target genes, Sirt1 and Pgc-1α (also known as Ppargc1a), in skeletal muscle of Mstn(-/-) mice.

CONCLUSIONS/INTERPRETATION

We conclude that myostatin inactivation leads to increased AMPK levels and activity resulting in increased insulin sensitivity of skeletal muscle. We propose that, by regulating AMPK in skeletal muscle and adipose tissues, myostatin plays a major role in regulating insulin signalling.

Interruption of the denitrification pathway influences cell growth and magnetosome formation in Magnetospirillum magneticum AMB-1

AIMS

Intracellular magnetosome synthesis in magnetotactic bacteria has been proposed to be a process involving functions of a variety of proteins. To learn more about the genetic control that is involved in magnetosome formation, nonmagnetic mutants are screened and characterized.

METHODS AND RESULTS

Conjugation-mediated transposon mutagenesis was applied to screen for nonmagnetic mutants of Magnetospirillum magneticum AMB-1 that were unable to respond to the magnetic field. A mutant strain with disruption of a gene locus encoding nitric oxide reductase was obtained. Growth and magnetosome formation under different conditions were further characterized.

CONCLUSIONS

Interruption of denitrification by inactivating nitric oxide reductase was responsible for the compromised growth and magnetosome formation in the mutant with shorter intracellular chains of magnetite crystals than those of wild-type cells under anaerobic conditions. Nevertheless, the mutant displayed apparently normal growth in aerobic culture.

SIGNIFICANCE AND IMPACT OF THE STUDY

Efficient denitrification in the absence of oxygen is not only necessary for maintaining cell growth but may also be required to derive sufficient energy to mediate the formation of magnetosome vesicles necessary for the initiation or activation of magnetite formation.

Physiological and molecular characterization of genetic competence in Streptococcus sanguinis

Streptococcus sanguinis is a major component of the oral flora and an important cause of infective endocarditis. Although S. sanguinis is naturally competent, genome sequencing has suggested significant differences in the S. sanguinis competence system relative to those of other streptococci. An S. sanguinis mutant possessing an in-frame deletion in the comC gene, which encodes competence-stimulating peptide (CSP), was created. Addition of synthetic CSP induced competence in this strain. Gene expression in this strain was monitored by microarray analysis at multiple time-points from 2.5 to 30 min after CSP addition, and verified by quantitative reverse transcription-polymerase chain reaction. Over 200 genes were identified whose expression was altered at least two-fold in at least one time point, with the majority upregulated. The 'late' response was typical of that seen in previous studies. However, comparison of the 'early' response in S. sanguinis with that of other oral streptococci revealed unexpected differences with regard to the number of genes induced, the nature of those genes, and their putative upstream regulatory sequences. Streptococcus sanguinis possesses a comparatively limited early response, which may define a minimal streptococcal competence regulatory circuit.

Spectral graph analysis of modularity and assortativity

Expressions and bounds for Newman's modularity are presented. These results reveal conditions for or properties of the maximum modularity of a network. The influence of the spectrum of the modularity matrix on the maximum modularity is discussed. The second part of the paper investigates how the maximum modularity, the number of clusters, and the hop count of the shortest paths vary when the assortativity of the graph is changed via degree-preserving rewiring. Via simulations, we show that the maximum modularity increases, the number of clusters decreases, and the average hop count and the effective graph resistance increase with increasing assortativity.

Single-shot femtosecond x-ray holography using extended references

In the context of x-ray lensless imaging, we present a recent approach for Fourier transform holography based on the use of extended references. Major advances shown here rely on a high signal efficiency and on the direct image reconstruction of the object performed by a simple linear derivative. Moreover, the extended holographic reference is easy to manufacture and can be applied to a variety of imaging experiments. Here we demonstrate single-shot imaging with a table-top, laser-based coherent soft x-ray source. A spatial resolution of 110 nm was obtained with an integration time of 20 fs.

Synthesis, characterization and ab initio simulation of magnesium-substituted hydroxyapatite

The substitution of magnesium in hydroxyapatite (HA) was examined in HA nano-crystals synthesized by the wet-chemical precipitation method at 90 degrees C. Comprehensive characterization techniques, including X-ray diffraction, X-ray fluorescence, field emission scanning electron microscopy, high-resolution transmission electron microscopy, thermogravimetric analysis and Rietveld refinement, provided experimental evidence of the effects of Mg substitution on the phase, crystallinity, chemical composition, crystal size, morphology, thermal stability and crystal lattice structure of HA. A computational study using ab initio generalized gradient approximation density functional theory was performed to reveal changes in lattice parameters and preferential calcium sites for Mg substitution in HA. The experimental results showed that a limited amount of Mg (Mg/(Mg+Ca) between 5 and 7 mol.%) could successfully substitute for Ca in HA. HA crystallites became smaller and more irregular, and they formed greater agglomerates with Mg substitution. Mg substitution resulted in decreases in the crystallinity and thermal stability of HA. The lattice constants, a and c, decreased with increasing Mg substitution. The simulation results revealed that the Ca(1) sites in HA lattices were energetically favored sites for Mg substitution.

Use of short echo time two-dimensional 1H-magnetic resonance spectroscopy in temporal lobe epilepsy with negative magnetic resonance imaging findings

We evaluated short echo time two-dimensional 1H magnetic resonance spectroscopy (2D-1HMRS) with the point-resolved spatial selection (PRESS) protocol in temporal lobe epilepsy (TLE) patients with negative magnetic resonance imaging (MRI) findings and described the characteristics of 2D-(1)HMRS in the epileptic focus. Thirty-eight TLE patients with negative conventional MRI findings and 10 healthy controls were studied by 2D-1HMRS. A 128-channel prolonged video-electroencephalographic (EEG) method was used as the standard for epileptogenic focus localization to evaluate N-acetyl aspartate/(choline + creatine + phosphocreatine) (NAA/[Cho + Cr-PCr]), glutamate + glutamine/creatine (Glx/Cr-PCr) and myo-inositol/Cr-PCr ratios in patients with negative MRI findings. The 2D-1HMRS showed that 32/38 patients and all healthy controls had stable baselines and good signal-to-noise ratios. Compared with the healthy controls, 32 patients showed abnormal NAA/(Cho + Cr-PCr) ratios in the hippocampus and, in 25 of these patients, focus lateralization agreed with the EEG. It is concluded that short echo time 2D-1HMRS with the PRESS protocol can help find abnormalities in lateralization of temporal epilepsy in patients with negative MRI findings.

Lessons from the diagnosis and treatment of spontaneous vertebral arterial dissection. Case report

SUMMARY

A 36-year-old man presented a sudden left occipital headache and right limb weakness after tooth-brushing. Conventional catheter digital subtraction angiography (DSA) showed a left VA occlusion at the crotch of the posterior inferior cerebellar artery. Four days later, the patient got worse. The angiogram showed the left vertebral artery had reopened and the basilar trunk occluded above the AICA. He died two days later and autopsy demonstrated a dissection of the basilar arteries. Based on the autopsy data from the patient in this study, we suggest that the BA dissection might be due to left VA dissection, and placing a stent on the juncture between the uninjured VA and the basilar trunk might be an effective method to prevent fatal BA occlusion.

Protective role of tretinoin and N-acetyl-L-cysteine from antiproliferative action of cigarette smoke extract on alveolar epithelial cells

To investigate the mechanisms by which tretinoin and N-acetyl-L-cysteine (NAC) reverse the growth inhibition of alveolar epithelial cells induced by cigarette smoke extract (CSE), MTT assay was used to evaluate cell viability. It was observed that both tretinoin and NAC could restore the viability of CSE-inhibited A549 cells. By incubation with fluorescent indicator H2DCFDA, it was documented that CSE-stimulated accumulation of intracellular reactive oxygen species (ROS) was obviously decreased by tretinoin or NAC. Furthermore, using semi-quantitative and real-time quantitative RT-PCR as well as western blot methods, high expression of insulin-like growth factor binding protein-2 (IGFBP-2) in A549 cells treated with CSE was found at both transcriptional and protein levels, and concomitant with the restoration of cell growth after treatment with tretinoin or NAC, down regulation of IGFBP-2 was observed. From the present study, it is concluded that both RA and NAC can antagonize CSE-induced growth arrest of alveolar epithelial cells and that down regulation of IGFBP-2 may play an important role in the process.

Pharmacological rescue of noise induced hearing loss using N-acetylcysteine and acetyl-L-carnitine

Despite the use of hearing protection devices (HPDs) and engineering changes designed to improve workspaces, noise-induced hearing loss continues to be one of the most common and expensive disabilities in the US military. Many service members suffer acoustic trauma due to improper use of HPDs, sound levels exceeding the protective capacity of the HPDs, or by unexpected, injurious exposures. In these cases, there is no definitive treatment for the hearing loss. This study investigated the use of the pharmacological agents N-acetylcysteine and acetyl-L-carnitine after acoustic trauma to treat cochlear injury. N-Acetylcysteine is an antioxidant and acetyl-L-carnitine a compound that maintains mitochondrial bio-energy and integrity. N-Acetylcysteine and acetyl-L-carnitine, respectively, significantly reduced permanent threshold shifts and hair cell loss compared to saline-treated animals when given 1 and 4 h post-noise exposure. It may be possible to obtain a greater therapeutic effect using these agents in combination or at higher doses or for a longer period of time to address the secondary oxidative events occurring 7-10 days after acute noise exposure.

Antibodies to Liver Sinusoidal Endothelial Cells Modulate Immune Responses in Liver Transplantation

AIM

Liver sinusoidal endothelial cells (LSECs) have been implicated to play a role in the induction of liver allograft rejections. Here, we studied the clinical consequences of preformed LSEC-reactive antibodies and their functional capacity in modulating T-cell responses.

METHODS

Pre- and posttransplant sera and T lymphocytes from 95 liver transplant patients were used in this study. LSECs were isolated from a normal healthy liver. Binding of antibodies to LSECs was detected using flow cytometric analysis. To study whether LSEC antibodies facilitated cell-mediated immunity, a mixed cell culture (MCC) assay was used. Cytokines in the supernatant of MCC were also measured by enzyme-linked immunosorbent assay. Immunohistochemical staining on liver biopsy sections was performed to detect deposition of immunoglobulins in LSEC during rejections.

RESULTS

Significantly higher numbers of patients with rejections had LSEC antibodies (35/50, 70%) compared with 8/45 (18%) without rejections (P < .0001). Purified fractions of LSEC antibodies induced the expression of the costimulatory marker CD86 on LSECs. Significantly higher numbers of patients with LSEC antibodies and rejections had an increased proliferation of T cells and markedly decreased levels of transforming growth factor (TGF)-beta in the MCC as compared with those without antibodies and rejections (P < .0001, P < .0001, respectively). Deposition of antibodies in LSECs during rejection episodes was observed in the biopsies of patients with LSEC antibodies but not in those without LSEC antibodies.

CONCLUSION

Our data suggest that antibodies to LSEC may facilitate acute liver allograft rejections by down-regulating the immune modulating cytokine TGF-beta and thus up-regulating alloreactive T-cell proliferation.

DNA vaccination with an insulin construct and a chimeric protein binding to both CTLA4 and CD40 ameliorates type 1 diabetes in NOD mice

Type 1 diabetes (T1D), a T-cell-mediated autoimmune disease, could be attributed to many defects in nonobese diabetic (NOD) mice, including deficient expressions of costimulatory molecules that impair antigen presentation. Thus, this deficient antigen presentation may result in a reduced ability to induce a tolerogenic response through negative selection/regulation of autoreactive T cells. Improperly activated T cells seem to be able to induce autoimmune responses causing diabetes. To re-establish tolerance to autoantigens by modulating costimulation, we constructed and tested a new type of DNA vaccine encoding a membrane-bound preproinsulin (mbPPI) and a chimeric gene vector encoding mutant B7.1/CD40L (mB7.1/CD40L) fusion protein. This mutant B7.1 binds CTLA4 but not CD28. We report that young NOD mice immunized with mbPPI along with mB7.1/CD40L DNA vectors significantly reduced diabetes incidence while treatment with CTLA4/IgG1 exacerbated diabetes. In conclusion, the combination of mbPPI and mB7.1/CD40L was able to protect against autoimmunity and diabetes in NOD mice possibly by promoting a more efficient presentation of autoantigen PPI and inducing specific tolerance to PPI by negatively regulating autoreactive T cells.

Stachyose extract from Rehmannia glutinosa Libosch. to lower plasma glucose in normal and diabetic rats by oral administration

The hypoglycemic effects of water extract and stachyose extract (Part III) from Rehmannia glutinosa Libosch. were investigated in this paper by oral administration to normal, glucose- and adrenaline-induced hyperglycemic and alloxan-induced diabetic rats. The results showed that Part III had the effect of lowering fasted plasma glucose level and partially preventing hyperglycemia induced by glucose (2.5 g x kg(-1), i.p.) and adrenaline (300 microg x kg(-1), i.p.), respectively, but no obvious dose-dependent effect was found when it was administered at the doses of 100, 200 and 400 mg x kg(-1) for 6 days, i.g. In alloxan-induced diabetic rats, Part III (200 mg x kg(-1) for 15 days, i.g.) gave a significant decrease in blood glucose level. The results suggested that Part III, which is mainly composed of stachyose from Rehmannia glutinosa Libosch., had a significant hypoglycemic effect in glucose- and adrenaline-induced hyperglycemic and alloxan-induced diabetic rats.

Environmental nano-pollutants (ENP) and aquatic micro-interfacial processes

The concepts of nano-science and technology are penetrating into the aspects of environmental science and technology. Environmental nano-pollutants (ENP) is suggested. as a specific category of pollutants that presents many common critical characters impacting the natural and social ecosystems. The outstanding properties are the various reactions in the macro-interfacial processes. Several examples as the adsorption of rare-earth metals on Chinese loess, the adsorption of PAHs on aquatic sediments with humic substances and the speciation of nano-flocculants in the water and wastewater treatment are discussed in the paper.

Viruses in subgroup 2 of the genus Ilarvirus share both serological relationships and characteristics at the molecular level

Sequence data have been determined for 5 members of subgroup 2 of the genus Ilarvirus. These data support the known serological relationships among accepted members of this group and indicate that the ilarvirus Hydrangea mosaic virus (HdMV) is an isolate of Elm mottle virus (EMoV). The close relationships between members of this subgroup, exhibited through the coat proteins coded on RNA 3, extend to the other genomic molecules. Primers designed from the sequences of RNA 1 and RNA 2 of EMoV amplified fragments from all other subgroup 2 viruses but not from other ilarviruses. Although closely related, members of this subgroup occur naturally in distinctly different host species. The possible origins of the viruses are discussed in relation to similarities among the genomic molecules, in particular RNA 3.

Serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), and their soluble receptors in coal workers' pneumoconiosis

The aim of this study was to investigate whether systemic tumor necrosis factor alpha (TNF-alpha), soluble TNF-alpha receptors (p55, p75), interleukin 6 (IL-6), and soluble IL-6 receptor could be markers of biological activities of coal workers' pneumoconiosis (CWP). The study population was composed of 182 Chinese retired coal miners who had similar dust exposure histories. Among them, 71 were cases with CWP and 111 were controls. Chest radiographs were classified according to International Labour Organization Criteria (ILO, 1980). Individual dust exposure variables were estimated from work histories, and smoking information was obtained from interviews. Serum concentrations of TNF-alpha, TNF-alpha receptors (p55, p75), IL-6, and IL-6 receptor were measured by ELISA techniques. Mean serum levels of p55, p75 and IL-6 were significantly higher in cases than in controls (P < or = 0.01 for each comparison by crude analyses). Results from logistic regression models, adjusted for age, dust exposure variables, and smoking habits, found similar associations between soluble p55 and p75 levels and the presence of CWP. Linear regression analysis revealed that CWP radiographic stage (by ILO criteria) was significantly correlated with the individual serum concentrations of p55, p75 and IL-6. Serum concentrations of all measured cytokines were notcorrelated to age, dust exposure, or smoking, but there were correlations between soluble p75 and p55 levels, and between p75 and IL-6 levels. The results of this study suggest that serum levels of TNF receptors and IL-6 are associated with the fibrotic process of CWP and serum cytokine levels may be correlated with the severity of CWP.

Pubertal transition, stressful life events, and the emergence of gender differences in adolescent depressive symptoms

This study examined the role of both pubertal and social transitions in the emergence of gender differences in depressive symptoms during adolescence. This study generated the following findings: (a) Gender differences in depressive symptoms emerged during 8th grade and remained significant through 12th grade. (b) Pubertal status in 7th grade was related to adolescent depressive symptoms over time. (c) Early-maturing girls represented the group with the highest rate of depressive symptoms. (d) Depressive symptoms measured in 7th grade predicted subsequent symptom levels throughout the secondary school years. (e) Recent stressful life events were associated with increased depressive symptoms. (f) Early-maturing girls with higher levels of initial symptoms and more recent stressful life events were most likely to be depressed subsequently. The findings demonstrate the importance of the interaction between the pubertal transition and psychosocial factors in increasing adolescent vulnerability to depressive experiences.

A strategy for the determination of enzyme kinetics using electrospray ionization with an ion trap mass spectrometer

A simple and rapid means of enzyme kinetic analysis was achieved using electrospray ionization mass spectrometry and a one-point normalization factor. The model system used, glutathione S-transferase from porcine liver, is a two-substrate enzyme catalyzing the conjugation of glutathione with a variety of compounds containing an electrophilic center. An internal standard that is structurally similar to the product was added to the reaction quench solution, and a single-point normalization factor was used to determine the product concentration without the need of a calibration curve. Kinetic parameters, such as Km, Vmax and Ki (for thyroxine), obtained by electrospray mass spectrometry agreed with those obtained from traditional UV-vis spectroscopy, and competitive vs noncompetitive inhibition reactions could be delineated via mass spectrometry. These results suggest that our method can be applied to enzymatic processes in which spectrophotometric or spectrofluorometric assays are not feasible or when the relevant substrates do not incorporate chromophores or fluorophores. This new method is competitive with traditional UV assays in that it is facile and it involves very little analysis time.

Specific amino acid deficiency alters the expression of genes in human melanoma and other tumor cell lines

This study determined the effect of tyrosine (Tyr) and phenylalanine (Phe) deprivation on protein expression and phosphorylation of mitogen-activated protein kinase kinase 4 (MKK4)/stress-activated protein/Erk kinase (SEK1), a metastasis suppressor gene. Differential display and suppressive subtractive hybridization techniques identified genes modulated by Tyr and Phe deprivation. Expression of MKK4/SEK1 protein varied widely among human A375, A375SM and SB2 melanoma, PC-3 and DU145 prostate cancer, and MDA-MB-231 breast cancer cell lines and within the different lines. Phosphorylation of the MKK4/SEK1 protein similarly varied. No differences in MKK4/SEK1 gene expression or in the 41 other metastasis and tumor suppressor genes were found in A375 melanoma cells cultured in Tyr- and Phe-deprived media. A number of up-regulated and down-regulated genes in A375 melanoma cells were identified by differential display and suppressive subtractive hybridization that were pertinent to regulation of cytoskeletal organization, cell movement, gene transcription and metastasis. Two tumor marker genes, the gene for enolase and FUS/CHOP, were down-regulated by Tyr and Phe deprivation. This study shows that tumor cells display heterogeneity in their response to deprivation of Tyr and Phe and that these amino acids may be signaling molecules that regulate gene expression and function in tumor cells.

Evidence for involvement of the neural pathway containing the peripheral vagus nerve, medullary visceral zone and central amygdaloid nucleus in neuroimmunomodulation

It is now evident that a bidirectional communication network exists between the central nervous system (CNS) and immune system (IS). However, the way in which the IS passes inform to the brain is not quite clear.In the present study, one of the neural pathways involved in the cytokine-to-brain communication was investigated in the rat. This pathway starts at the vagal nerve projecting to the medullary visceral zone (MVZ), an arc-shape band from the dorsomedial to ventrolateral area in the middle-caudal segment of the medulla oblongata, and terminates at the central amygdaloid nucleus (Ce) which receives projections from large catecholaminergic neurons in the MVZ. Animals were randomly divided into two experimental groups. Triple-labeling was used in Group I animals to combine wheat germ aggulutinin-conjugated horseradish peroxidase (WGA-HRP) retrograde tracing with anti-Fos and anti-tyrosine hydroxylase (TH) immunostaining. WGA-RP was stereotaxically injected into the unilateral Ce of the animals and, after a survival period of 48 h, intraperitoneal (IP) injection of lipopolysaccharide (LPS) was performed. Seven kinds of labeled neurons were observed in the MVZ, namely, HRP-, Fos- or TH-singly-labeled neurons; Fos/HRP-, Fos/TH- or HRP/TH-doubly-labeled neurons; and Fos/HRP/TH-triply-labeled neurons. As for Group II animals, bilateral subdiaphragmatic vagotomy (SDV) or sham operation was performed, followed 4 weeks later by IP injection of LPS. The number of Fos-positive neurons within the Ce and MVZ was significantly lower (P<0.01) in rats having SDV when compared with those receiving sham operation. Our results suggest that part of the peripheral immune information can be conveyed through the vagus to the catecholaminergic neurons in the MVZ, where it is transported to the Ce. The MVZ is a neural relay station in the immune-to-brain communication and might play a significant role in neuroimmuno-modulation via the vagus-MVZ-Ce pathway.

A library approach to the generation of bisubstrate analogue sulfotransferase inhibitors

[reaction: see text]. A library of potential bisubstrate analogue inhibitors (1) targeting sulfotransferase enzymes was generated by the chemoselective ligation of the PAPS mimic 2 with a panel of 447 aldehydes. Preliminary screening has identified compounds that inhibit estrogen sulfotransferase (EST), an enzyme relevant to breast cancer.