Review: placenta-specific microRNAs in exosomes - good things come in nano-packages

MicroRNAs (miRNAs) are small noncoding RNA gene products that commonly regulate mRNA expression by repression of translation and/or transcript decay. Whereas common and unique types of miRNAs are expressed by the placenta during pregnancy, the functions of most placental miRNA species are unknown. In addition to their intracellular silencing function, miRNAs are also released to the extracellular space and systemic circulation, where they can potentially target cells to regulate mRNA and protein expression, providing a non-hormonal means of intercellular communication that contributes to tissue homeostasis and disease pathophysiology. This review centers on extracellular miRNAs that originate in trophoblasts and that could mediate crosstalk between the feto-placental unit and the mother during pregnancy. We specifically detail the function of miRNAs from the primate-specific chromosome 19 miRNA cluster. These miRNAs are highly expressed in human placentas and in the serum of pregnant women. They are also packaged into extracellular vesicles of diverse sizes, including exosomes, and endow non-trophoblastic cells with resistance to a variety of viruses.

Value of transvaginal sonography in diagnosing heterotopic pregnancy after in-vitro fertilization with embryo transfer

OBJECTIVES

To assess the value of transvaginal sonography (TVS) in the diagnosis of heterotopic pregnancy (HP) in the first trimester after in-vitro fertilization with embryo transfer (IVF-ET).

METHODS

This was a retrospective review of women undergoing IVF-ET between January 2005 and December 2011. Women were diagnosed with an HP using TVS if a visible intrauterine gestational sac was observed with any of the following: (i) an inhomogeneous adnexal mass; (ii) an empty extrauterine gestational sac seen as a hyperechoic ring; or (iii) a yolk sac and/or fetal pole with or without cardiac activity in an extrauterine sac.

RESULTS

Overall, 16 483 consecutive women who underwent IVF had TVS during the study. Of these, 174 cases were diagnosed on TVS as having an HP, and 10 cases were missed. Fifty-two cases were treated expectantly and were excluded from the analysis. Three types of ultrasonographic presentation of ectopic pregnancy (EP) were seen in HP patients, with a gestational sac found in 70 cases, a ring sign in 21 and an adnexal mass in 31. The sensitivity and specificity of TVS for the detection of HP were 92.4 and 100%, respectively, with positive and negative predictive values of 100 and 99.9%. The HP cases comprised 103 tubal EPs and 29 non-tubal EPs. In 93 patients (70.5%), their intrauterine pregnancy resulted in a live birth, 37 patients (28.0%) suffered an early miscarriage and two patients (1.5%) had a late miscarriage.

CONCLUSION

Early TVS performed by an experienced sonographer has a high sensitivity for making the correct diagnosis of HP after IVF-ET.

Effects of degradable MG-ND-ZN-ZR alloy on osteoblastic cell function

This study aimed to investigate the effects of a novel patented Mg-3Nd-0.2Zn-0.4Zr (weight %, JDBM) alloy on osteoblastic cell function, as these cells play an important role in bone repair and remodeling. The associated effects of the JDBM alloy on osteoblastic cell function involving cell adhesion, cell proliferation, and mineralization were investigated using scanning electron microscopy (SEM), MTT assay and ambramycin staining, respectively. At the same time, the in vitro degradation behavior of the JDBM alloy in cell culture medium was evaluated by the weight-loss method and SEM. Pure magnesium was used as control. The results showed that osteoblastic cells cultured on JDBM alloy samples manifested better cell adhesion, improved cell proliferation and increased mineralization ability, compared with cells seeded on pure magnesium samples. Our data indicate that the JDBM alloy has excellent bioactivity, improving the cell function of osteoblastic cells seeded on it.

Estimation of lateral water flow and bromide transport in a subsurface seepage irrigation system

Subsurface seepage irrigation is a common method used by growers in the Tri-County Agricultural Area (TCAA), Florida, USA, owing to its cost-effectiveness and low maintenance requirements. This study investigated the lateral flow of the perched water and the lateral transport of bromide (Br-) in this irrigation system in the TCAA and estimated the potential discharge of Br- into the drainage canals at the edges of the field, using the Visual MODFLOW/ MT3DMS models in conjunction with field experiments. Simulations showed that the perched water flowed from the northeast to the southwest of the field. Migration of the Br- plume from the source areas toward the canals was very slow and varied depending on the selection of the outer Br- concentration contour levels. However, the lateral transport of Br- from the perched water into the canals occurred after about 61 days. The simulations further revealed that the rate of perched water Br- discharge into the canals averaged 8.6 g day(-1) during a 30-day discharge period (from 61 to 91 days). This rate is very important for estimating Br- discharge into the canals and could also provide useful information for evaluating dissolved nutrient discharge into canals from the subsurface seepage irrigation system.

A temperature window for the synthesis of single-walled carbon nanotubes by catalytic chemical vapor deposition of CH4 over Mo-Fe/MgO catalyst

A temperature window of single-walled carbon nanotubes (SWCNTs) growth has been studied by Raman spectroscopy. The results presented when temperature lower than 750 degrees C, there were few SWCNTs formed, and when temperature higher than 900 degrees C, mass amorphous carbons were formed in the SWCNTs bundles due to the self-decomposition of CH4. The temperature window of SWCNTs efficiently growth is between 800 and 900 degrees C, and the optimum growth temperature is about 850 degrees C. These results were supported by transmission electron microscope images of samples formed under different temperature. The temperature window is important for large-scale production of SWCNTs by catalytic chemical vapor deposition method.

Novel SACS mutation in a Belgian family with sacsin-related ataxia

The authors describe the four patients in the first known Belgian family with autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). A novel homozygous missense mutation, NM_014363.3: c.3491T>A in exon 9, of the SACS gene was identified in the present family, which results in an original amino acid of methionine to lysine substitution at amino acid residue 1164 (p.M1164K). Although the cardinal clinical features, i.e., spastic ataxia with peripheral neuropathy, in our patients were similar to those in Quebec patients, our patients exhibited some atypical clinical features, e.g., teenage-onset and absence of retinal hypermyelination. The present family is from Wallonia, and there could be shared ethnicity with the families of Charlevoix-Saguenay.

Assessment of seasonal variations in surface water quality

Assessment of seasonal changes in surface water quality is an important aspect for evaluating temporal variations of river pollution due to natural or anthropogenic inputs of point and non-point sources. In this study, surface water quality data for 16 physical and chemical parameters collected from 22 monitoring stations in a river during the years from 1998 to 2001 were analyzed. The principal component analysis technique was employed to evaluate the seasonal correlations of water quality parameters, while the principal factor analysis technique was used to extract the parameters that are most important in assessing seasonal variations of river water quality. Analysis shows that a parameter that is most important in contributing to water quality variation for one season may not be important for another season except for DOC and electrical conductance, which were always the most important parameters in contributing to water quality variations for all four seasons.

16q-linked autosomal dominant cerebellar ataxia: a clinical and genetic study

The autosomal dominant cerebellar ataxias (ADCAs) comprise a genetically and clinically heterogenous group of neurodegenerative disorders. Very recently, a C-to-T single nucleotide substitution in the puratrophin-1 gene was found to be strongly associated with a form of ADCA linked to chromosome 16q22.1 (16q-linked ADCA; OMIM 600223). We found the C-to-T substitution in the puratrophin-1 gene in 20 patients with ataxia (16 heterozygotes and four homozygotes) and four asymptomatic carriers in 9 of 24 families with an unknown type of ADCA. We also found two cases with 16q-linked ADCA among 43 sporadic patients with late-onset cortical cerebellar atrophy (LCCA). The mean age at onset in the 22 patients was 61.8 years, and that of homozygous patients was lower than that of heterozygous ones in one family. Neurological examination revealed that the majority of our patients showed exaggerated deep tendon reflexes in addition to the cardinal symptom of cerebellar ataxia (100%), and 37.5% of them had sensorineural hearing impairment, whereas sensory axonal neuropathy was absent. The frequency of 16q-linked ADCA was about 1/10 of our series of 110 ADCA families, making it the third most frequent ADCA in Japan.

Sacsin-related ataxia (ARSACS): expanding the genotype upstream from the gigantic exon

The authors describe a Japanese autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) patient with a compound heterozygous mutation (32627-32636delACACTGTTAC and 31760delT) in a new exon of the SACS gene. The new exons upstream of the gigantic one should be analyzed when a case is clinically compatible with ARSACS, even without any mutation in the gigantic exon.

Temporal and spatial distributions of sediment total organic carbon in an estuary river

Understanding temporal and spatial distributions of naturally occurring total organic carbon (TOC) in sediments is critical because TOC is an important feature of surface water quality. This study investigated temporal and spatial distributions of sediment TOC and its relationships to sediment contaminants in the Cedar and Ortega Rivers, Florida, USA, using three-dimensional kriging analysis and field measurement. Analysis of field data showed that large temporal changes in sediment TOC concentrations occurred in the rivers, which reflected changes in the characteristics and magnitude of inputs into the rivers during approximately the last 100 yr. The average concentration of TOC in sediments from the Cedar and Ortega Rivers was 12.7% with a maximum of 22.6% and a minimum of 2.3%. In general, more TOC accumulated at the upper 1.0 m of the sediment in the southern part of the Ortega River although the TOC sedimentation varied with locations and depths. In contrast, high concentrations of sediment contaminants, that is, total polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), were found in sediments from the Cedar River. There was no correlation between TOC and PAHs or PCBs in these river sediments. This finding is in contradiction to some other studies which reported that the sorption of hydrocarbons is highly related to the organic matter content of sediments. This discrepancy occurred because of the differences in TOC and hydrocarbon source input locations. It was found that more TOC loaded into the southern part of the Ortega River, while almost all of the hydrocarbons entered into the Cedar River. This study suggested that the locations of their input sources as well as the land use patterns should also be considered when relating hydrocarbons to sediment TOC.

Sorption kinetics and equilibria of organic pesticides in carbonatic soils from South Florida

A batch reactor was used to determine sorption kinetic parameters (k2, F, and K*) and the equilibrium sorption coefficient (K). The two-site nonequilibrium (TSNE) batch sorption kinetics model was used to calculate the kinetic parameters. Two probe organic pesticides, atrazine [2-chloro-4-ethylamino-6-isopropylamino-s-triazine] and diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] were studied using three carbonatic soils from South Florida (Chekika, Perrine, and Krome), one noncarbonatic soil from Iowa (Webster), and one organic soil (Lauderhill) from South Florida. Carbonatic soils contained more than 600 g kg(-1) CaCO3. Sorption is initially very fast up to 3 h and then slowly reaches equilibrium. All soil-chemical combinations reached sorption equilibrium after about 24 h and all sorption isotherms were linear. The sorption kinetics data were well described by the TSNE model for all soil-chemical combinations except for the marl soil data (Perrine-Atrazine), which were better described by the one-site nonequilibrium (OSNE) model. Diuron, with higher K, undergoes slower sorption kinetics than atrazine. The Lauderhill soil containing organic carbon (OC) of 450 g kg(-1) exhibited slowest sorption kinetics for both pesticides. An inverse relationship between k3 and K was observed for atrazine and diuron separately in Chekika, Webster, and Lauderhill soils but not in Perrine and Krome soils. The sorption kinetic parameters were used to distinguish the sorption behavior between atrazine and diuron and to identify differences between soils. Normalizing the sorption coefficient (K) to OC showed that atrazine and diuron had K oc values in carbonatic soils that were a third of reported literature values for noncarbonatic soils. Using existing literature K oc values in solute transport models will most likely underestimate the mobility of atrazine, diuron, and other neutral organic chemicals in carbonatic soils.

Simulation of phytoremediation of a TNT-contaminated soil using the CTSPAC model

Knowledge of water movement in the plant-xylem system and contaminant bioavailability in the soil environment is crucial to evaluate the success of phytoremediation practices. This study investigated the removal of 2,4,6-trinitrotoluene (TNT) from a contaminated sandy soil by a single poplar (Populus fastigiata) tree through the examinations of temporal variations of xylem water potential, root water uptake, and soil TNT bioavailability. A mathematical model, CTSPAC (Coupled Transport of water, heat, and solutes in the Soil-Plant-Atmosphere Continuum), was modified for the purpose of this study. The model was calibrated using laboratory measurements before its application. Our simulations show that the xylem water potential was high in the roots and low in the leaves with a potential head difference of 3.55 cm H2O, which created a driving force for water flow and chemical transport upward from the roots through the stem to the leaves. The daily average root water uptake rate was 25 cm3 h(-1) when an equilibrium condition was reached after 24 h. Our simulations further reveal that no TNT was found in the stem and leaves and only about 1% of total TNT mass was observed in the roots due to the rapid biodegradation and transformation of TNT into its daughter products. About 13% of the soil TNT was removed by the poplar tree, resulting mainly from root uptake since TNT is a recalcitrant compound. In general, the soil TNT bioavailability decreased with time due to the depletion of soil solution TNT by the poplar tree. A constant bioavailability (i.e., 3.1 x 10(-6)) was obtained in 14 d in which the soil TNT concentration was about 10 mg L(-1). Our study suggests that CTSPAC is a useful model to simulate phytoremediation of TNT-contaminated sites.

A new surface-enhanced Raman scattering system for carbon nanotubes

A new surface-enhanced Raman scattering (SERS) system of carbon nanotubes (CNTs) is reported for the first time. According to the remarkable mechanical property, CNTs were grinded on a sheet of silver directly. Thus rough silver surface was obtained, at the same time, the CNTs attached to the rough silver surface. High quality SERS spectra were obtained from CNTs attached to the rough silver surface. Because there were no solvents affecting the SERS of CNTs, the dependability of the result is improved. The theory and experiment results indicate that this is an accurate and practicable method for SERS study of CNTs.

Characterization of the pesticide chlordane in estuarine river sediments

Sediments are increasingly recognized as both carrier and potential source of contaminants in aquatic environments. This study investigated the characteristics and spatial distribution of total chlordane and its three most abundant compounds, including alpha-chlordane, gamma-chlordane, and trans-nonachlor, in sediments from the Cedar and Ortega rivers, Florida, USA, using geographic information system (GIS)-based kriging analyses and field measurements. Kriging analysis showed that two areas, one from the Cedar River area and the other from the northern end of the Ortega River area, were contaminated. The maximum concentrations of total chlordane, gamma-chlordane, alpha-chlordane, and trans-nonachlor in the sediments were, respectively, 101.8, 20.1, 26.3, and 19.2 microg/kg. A plot of total organic carbon (TOC)-normalized chlordane concentrations showed that effects of grain size on sediment chlordane contamination were negligible. A principal axis analysis further revealed that a linear correlation existed between alpha-chlordane and total chlordane as well as between gamma-chlordane and total chlordane, whereas no correlation existed between trans-nonachlor and total chlordane. Comparison of total chlordane concentration with Florida Sediment Assessment Guidelines showed that the Cedar River and the northern end of the Ortega River had total chlordane concentrations above the probable effect level (4.79 microg/kg), which could pose a potential risk to aquatic life.

Genome-wide analysis of defense-responsive genes in bacterial blight resistance of rice mediated by the recessive R gene xa13

Defense responses triggered by dominant and recessive disease resistance (R) genes are presumed to be regulated by different molecular mechanisms. In order to characterize the genes activated in defense responses against bacterial blight mediated by the recessive R gene xa13, two pathogen-induced subtraction cDNA libraries were constructed using the resistant rice line IRBB13--which carries xa13--and its susceptible, near-isogenic, parental line IR24. Clustering analysis of expressed sequence tags (ESTs) identified 702 unique expressed sequences as being involved in the defense responses triggered by xa13; 16% of these are new rice ESTs. These sequences define 702 genes, putatively encoding a wide range of products, including defense-responsive genes commonly involved in different host-pathogen interactions, genes that have not previously been reported to be associated with pathogen-induced defense responses, and genes (38%) with no homology to previously described functional genes. In addition, R-like genes putatively encoding nucleotide-binding site/leucine rich repeat (NBS-LRR) and LRR receptor kinase proteins were observed to be induced in the disease resistance activated by xa13. A total of 568 defense-responsive ESTs were mapped to 588 loci on the rice molecular linkage map through bioinformatic analysis. About 48% of the mapped ESTs co-localized with quantitative trait loci (QTLs) for resistance to various rice diseases, including bacterial blight, rice blast, sheath blight and yellow mottle virus. Furthermore, some defense-responsive sequences were conserved at similar locations on different chromosomes. These results reveal the complexity of xa13-mediated resistance. The information obtained in this study provides a large source of candidate genes for understanding the molecular bases of defense responses activated by recessive R genes and of quantitative disease resistance.

Frequency of arteriovenous shunts in hepatic cavernous hemangiomas in adults as seen on selective arteriography and postembolization radiography

PURPOSE

To study the frequency and angiographic findings of arteriovenous shunts (AVS) associated with adult cavernous hemangiomas of the liver (CHL) on hepatic artery digital subtraction angiography (DSA) and optimize the imaging technique of DSA to improve its diagnostic efficacy.

METHODS

We retrospectively analyzed 43 intraarterial DSA procedures performed on 30 adults with CHL. Of the 30 patients 22 were found to have an AVS. Transcatheter arterial embolization with Lipiodol (L-TAE) was performed on 21 of these and radiographs were taken immediately after embolization to observe the distribution of the injected iodized oil. The results were compared with those of the AVS found on DSA images.

RESULTS

AVS were identified by DSA in 22 (73.3%) of 30 patients. All AVS were located in the peritumoral liver tissue and had a parallel track appearance, or early filling of small draining veins during the arterial phase of DSA. Radiographs taken immediately after L-TAE in 21 of the 22 cases with AVS showed iodized oil filling a few portal branches or draining veins as a result of incompletely occluded shunts in 11 patients. In 10 patients there was complete occlusion and no filling of any vein, or only the originating end of draining veins filled with iodized oil. No evidence of AVS was found in the other eight patients in this series, and in six of these the DSA was not considered diagnostic.

CONCLUSION

The present study indicates that AVS are frequently seen in adults with CHL. DSA with high-quality images is helpful in identifying small AVS of CHL. The formation of an AVS in CHL may be closely related to the pathological changes in the peritumoral liver tissue.

[Clinical study on preventing endodontic interappointment pain with dexamethasone]

OBJECTIVE

To investigate the effect decreasing of the incidence of endodontic interappointment pain(EIP) by local injection of 5 mg dexamethasone.

METHODS

5 mg dexamethasone was injected submucosally at apical region of 80 teeth with asymtomatic pulp necrosis after root canal therapy, then observing the incidence of EIP and compared with control group.

RESULTS

The clinical observation revealed that the incidence of EIP of dexamethasone group (10.00%) was lower than that of control group (33.75%), P < 0.01, and the level of pain was decreased. Ordinal logistic regression revealed that EIP was related to tooth location, fistula, and root canal therapy.

CONCLUSION

The incidence of EIP can be reduced after 5 mg dexamethasone local injected.

[Investigation of a-SiOxNy thin film by infrared absorption]

Infrared absorptive characteristics of a-SiOxNy thin film was investigated by altering O and N content. Various molecular bonds were identified by the infrared absorption measurement. 1,105 and 865 cm-1 peaks are associated with single Si-O and Si-N modes respectively. When the O and N contents increase, the peaks associated with the symmetry and anti-symmetry modes of O-Si-O and N-Si-N are measured. For N-Si-O, the absorptive peaks of Si-O and Si-N mode are located at 1,036 and 890 cm-1 respectively.

Mechanisms of altered transcription by cigarette smoke

The article highlighted in this issue is "The Activity of NF-kappaB in Swiss 3T3 Cells Exposed to Aqueous Extracts of Cigarette Smoke Is Dependent on Thioredoxin," by Stephan Gebel and Thomas Müller (pp. 75-81).

Involvement of caspase-3 in cell death after hypoxia-ischemia declines during brain maturation

The involvement of caspase-3 in cell death after hypoxia-ischemia (HI) was studied during brain maturation. Unilateral HI was produced in rats at postnatal day 7 (P7), 15 (P15), 26 (P26), and 60 (P60) by a combination of left carotid artery ligation and systemic hypoxia (8% O2). Activation of caspase-3 and cell death was examined in situ by high-resolution confocal microscopy with anti-active caspase-3 antibody and propidium iodide and by biochemical analysis. The active caspase-3 positive neurons were composed of more than 90% HI damaged striatal and neocortical neurons in P7 pups, but that number was reduced to approximately 65% in striatum and 34% in the neocortex of P15 pups, and approximately 26% in striatum and 2% in neocortex of P26 rats. In P60 rats, less than 4% of the damaged neurons in striatum and less than 1% in neocortex were positive for active caspase-3. Western blot analysis demonstrated that the level of inactive caspase-3 in normal forebrain tissue gradually declined from a high level in young pups to very low levels in adult rats. Concomitantly, HI-induced active caspase-3 was reduced from a relatively high level in P7, to moderate levels in P15 and P26, to a barely detectable level in P60 rats. The authors conclude that the involvement of caspase-3 in the pathogenesis of cell death after HI declines during neuronal maturation. The authors hypothesize that caspase-3 may play a major role in cell death in immature neurons but a minor role in cell death in mature neurons after brain injury.

Suppression of human IL-1beta, IL-2, IFN-gamma, and TNF-alpha production by cigarette smoke extracts

BACKGROUND

Although cigarette smoking is known to have detrimental effects on the immune system, the nature of the immunosuppressive agent or agents is poorly understood.

OBJECTIVE

The purpose of the current study was to evaluate the effects of cigarette smoke extracts from high-tar (unfiltered Camel), medium-tar (Marlboro), and low-tar (Carlton) cigarettes on the in vitro production of IL-1beta, IL-2, IFN-gamma, and TNF-alpha.

METHODS

The concentrations of hydroquinone and catechol in cigarette smoke extracts were determined by using HPLC. Human PBMCs were treated with cigarette smoke extracts, hydroquinone, or catechol, and stimulated with anti-CD3 and phorbol-12-myristate-13-acetate. Cytokine levels in the supernatants were quantified by ELISA.

RESULTS

Pretreatment of PBMCs with cigarette smoke extracts derived from a single high- or low-tar cigarette suppressed the production of IL-1beta, IL-2, IFN-gamma, and TNF-alpha by greater than 90% without significant loss of cell viability. Nicotine, at a concentration comparable with that found in the highest-tar cigarettes (200 microg/mL), suppressed the production of IL-2, IFN-gamma, and TNF-alpha by only 21% to 38%. Catechol (50 micromol/L) inhibited production of IL-2 and IL-1beta by 62% to 73% but had little effect on TNF-alpha or IFN-gamma production. In contrast, hydroquinone inhibited the production of all 4 cytokines with IC(50) values ranging from 3 micromol/L(IL-1beta) to 29 micromol/L (IFN-gamma). However, HPLC determination of the hydroquinone concentrations in cigarette smoke extracts from single Camel (33+/-4 micromol/L), Marlboro (13+/-2 micromol/L), and Carlton (<1 micromol/L) cigarettes clearly demonstrated that the potent inhibitory effects of the low-tar cigarettes could not be accounted for by either hydroquinone or catechol.

CONCLUSION

These studies indicate that cigarette smoke contains potent inhibitors of cytokine production, at least one of which is present even in low-tar cigarettes.

Modulation of transcription factor AP-1 activity in murine EL-4 thymoma cells by vomitoxin (deoxynivalenol)

Trichothecene mycotoxins have been reported to suppress or superinduce cytokine mRNA expression by leukocytes both in vitro and in vivo. Modulation of transcription factor activities may be critical for these observations. Here, the effect of trichothecene vomitoxin (VT, deoxynivalenol) on activator protein-1 (AP-1) activity was determined in the murine EL-4 thymoma. Electrophoretic mobility shift assay (EMSA) revealed that VT modulated AP-1 binding activity in a concentration- and time-dependent manner when using a synchronous model in which VT was added concurrently with phorbol 12-myristate 13-acetate (PMA) and ionomycin (ION) to EL-4 cells. Induction of AP-1 binding activity by PMA/ION was suppressed in the presence of VT for a short period (1 to 12 h), but was enhanced upon prolonged VT exposure (48 to 72 h). VT also enhanced AP-1 binding activity when added to the cell culture 12 h after PMA/ION activation (delayed synchronous model). Using specific antibodies against AP-1 complex proteins, it was demonstrated by gel supershift assay that VT preferentially affected phosphorylated c-Jun, Jun B, c-Fos, and Fra-2 binding activities, whereas it did not alter Jun D and Fra-1 binding. A transient transfection assay demonstrated that these increased binding activities are associated with enhanced AP-1 transactivation potential. Elevation of AP-1 activity may contribute to cytokine dysregulation and immunotoxic effects associated with exposure to trichothecene mycotoxins such as VT.

Tetanic stimulation leads to increased accumulation of Ca(2+)/calmodulin-dependent protein kinase II via dendritic protein synthesis in hippocampal neurons

mRNA for the alpha-subunit of CaMKII is abundant in dendrites of neurons in the forebrain (Steward, 1997). Here we show that tetanic stimulation of the Schaffer collateral pathway causes an increase in the concentration of alpha-CaMKII in the dendrites of postsynaptic neurons. The increase is blocked by anisomycin and is detected by both quantitative immunoblot and semiquantitative immunocytochemistry. The increase in dendritic alpha-CaMKII can be measured 100-200 micrometer away from the neuronal cell bodies as early as 5 min after a tetanus. Transport mechanisms for macromolecules from neuronal cell bodies are not fast enough to account for this rapid increase in distal portions of the dendrites. Therefore, we conclude that dendritic protein synthesis must produce a portion of the newly accumulated CaMKII. The increase in concentration of dendritic CaMKII after tetanus, together with the previously demonstrated increase in autophosphorylated CaMKII (Ouyang et al., 1997), will produce a prolonged increase in steady-state kinase activity in the dendrites, potentially influencing mechanisms of synaptic plasticity that are controlled through phosphorylation by CaMKII.

[Experimental study on the effect of restorative dentin formation with human dentin phosphoprotein in immature permanent teeth of minipig]

OBJECTIVE

To investigate the function of human dentin phosphoprotein(DPP) on dentine mineralization in vivo.

METHODS

Pulp capping with human DPP was made in the permanent teeth of minipigs with calcium hydroxide and zinc oxide eugenol cement as controls. The minipigs were sacrificed at intervals of 14, 30, 90 days respectively after operation.

RESULTS

The histopathological results revealed that pulp cells had developed into odontoblastoid cells around the major restorative dentin body after two weeks. There was complete restorative dentin bridge a month later. The bridge became thick and dense, and mainly was tubular dentin in 3 month. There were well developed odontoblasts under the bridge. In the calcium hydroxide capping group, inflammatory cytonecrosis zone was found in the surface of dental pulp and only a little calcial bodies formed in two weeks. Complete restorative dentin bridge was formed in 1 to 3 months, the speed of dentin bridge formation was not as quick as that of DPP group.

CONCLUSION

DPP can induce pulp cells to develop into odontoblasts and formation of dentin bridge with little stimulation to the dental pulp. This study suggests that DPP plays an important role in the biomineralization of dentin development and restoration.

[The isolation and characterization of dentin phosphoprotein from human dentine]

OBJECTIVE

To establish the method of isolation and characterization of dentin phosphoprotein (DPP) from human dentine.

METHODS

Dentin powder was placed in dialysis tube after demineralized to completion with 0.6 mol/L HCl, then isolated DPP through DEAE-Sepharose CL6B anion exchange chromatography. Its protein composition, organic phosphorus content, molecular weight and amino acid were analyzed.

RESULTS

DPP contained high organic phosphorus, 23.8% of aspartic residue and 19.1% serine residue; their molecular weight were 141, 000, 124, 000, 108, 000 respectively.

CONCLUSION

DPP can be extracted from human dentine with 0.6 mol/L HCl demineralization. and DEAE-Sepharose CL6B anion exchange chromatography. It is a group of proteins which have a high content of organic phosphorus and is found to be rich in serine and aspartic acid residues.

Phospholipase A2 inhibitors p-bromophenacyl bromide and arachidonyl trifluoromethyl ketone suppressed interleukin-2 (IL-2) expression in murine primary splenocytes

Phospholipase A2 (PLA2) has been postulated to play a role in the regulation of cytokine expression. Therefore, the objective of the present study was to investigate the effects of PLA2 inhibitors p-bromophenacyl bromide (BPB) and arachidonyl trifluoromethyl ketone (AACOCF3) on interleukin-2 (IL-2) expression in murine primary splenocytes. Pretreatment of the splenocytes with both BPB and AACOCF3 suppressed phorbol 12-myristate 13-acetate plus ionomycin-induced IL-2 secretion in a concentration-dependent manner. Inhibition > 90% of IL-2 secretion was observed at 1 microM BPB and 10 microM AACOCF3 compared to the respective vehicle control. Likewise, IL-2 steady-state mRNA expression was inhibited by both PLA2 inhibitors in a concentration-dependent fashion with > 90% inhibition at 1 microM BPB and 20 microM AACOCF3. Taken together, these data demonstrated that PLA2 inhibitors BPB and AACOCF3 are robust inhibitors of IL-2 expression at both the mRNA and protein levels in murine splenocytes. Moreover, these findings suggest that drugs and chemicals which inhibit PLA2 may have marked effects on T-cell function.

Resonating circadian clocks enhance fitness in cyanobacteria

In some organisms longevity, growth, and developmental rate are improved when they are maintained on a light/dark cycle, the period of which "resonates" optimally with the period of the endogenous circadian clock. However, to our knowledge no studies have demonstrated that reproductive fitness per se is improved by resonance between the endogenous clock and the environmental cycle. We tested the adaptive significance of circadian programming by measuring the relative fitness under competition between various strains of cyanobacteria expressing different circadian periods. Strains that had a circadian period similar to that of the light/dark cycle were favored under competition in a manner that indicates the action of soft selection.

Suppression of interleukin-2 by the putative endogenous cannabinoid 2-arachidonyl-glycerol is mediated through down-regulation of the nuclear factor of activated T cells

2-Arachidonyl-glycerol (2-Ara-Gl) recently was identified as a putative endogenous ligand for cannabinoid receptor types CB1 and CB2 by competitive binding. More recent immune function assays demonstrated that 2-Ara-Gl possessed immunomodulatory activity. Because several plant-derived cannabinoids inhibit interleukin-2 (IL-2) expression, 2-Ara-Gl was investigated for its ability to modulate this cytokine. The direct addition of 2-Ara-Gl to mouse splenocyte cultures suppressed phorbol-12-myristate-13-acetate plus ionomycin-induced IL-2 secretion and steady state mRNA expression in a dose-dependent manner. 2-Ara-Gl also produced a marked inhibition of IL-2 promotor activity as determined by transient transfection of EL4.IL-2 cells with a pIL-2-CAT construct. 2-Ara-Gl at 5, 10, 20, and 50 microM suppressed phorbol-12-myristate-13-acetate plus ionomycin-induced IL-2 promotor activity by 18%, 28%, 39%, and 54%, respectively. To further characterize the mechanism for the transcriptional regulation of IL-2 by 2-Ara-Gl, the DNA-binding activity of transcription factors, nuclear factor of activated T cells (NF-AT), nuclear factor for immunoglobulin kappa chain in B cells (NF-kappa B/Rel), activator protein-1(AP-1), octamer, and cAMP-response element binding protein was evaluated by electrophoretic mobility shift assay in mouse splenocytes. In addition, a reporter gene expression system for p(NF-kappa B)3-CAT, p(NF-AT)3-CAT, and p(AP-1)3-CAT was used in transiently transfected EL4.IL-2 cells to determine the effect of 2-Ara-Gl on promoter activity for each of the specific transcription factors. 2-Ara-Gl reduced both the NF-AT-binding and promoter activity in a dose-dependent manner and, to a lesser degree, NF-kappa B/Rel-binding and promoter activity. No significant effect was observed on octamer- and cAMP-response element-binding activity. AP-1 DNA-binding activity was not inhibited by 2-Ara-Gl, but a modest inhibition of promoter activity was observed.

[Proliferative effect of low energy laser and colony stimulating factor on human umbilical cord blood hematopoietic cells]

OBJECTIVE

To study the proliferative effect of low energy laser on human cord blood hematopoietic cells in vitro and the relationship between the effect of low energy laser and colony stimulating factor (CSF).

METHODS

Human umbilical cord blood hematopoietic cells were irradiated with copper vapour laser and cultured in vitro. The number of colony and cells was calculated.

RESULTS

Laser irradiation synergized with CSF in expansion of cord blood hematopoietic cell. The GM-CFUc number from the group treated with irradiation plus CSF increased significantly as compared with that from other groups including laser irradiation or CSF treatment alone or control (P < 0.01). Reincubation of cord blood cells in the soft agar medium revealed that secondary colonies were formed and the absolute number of colony was obviously increased as compared with that before liquid culture. The number of colony in irradiation group was more than these of non-irradiation group.

CONCLUSION

Low energy laser irradiation for cord blood stem cells is effective in vitro expansion of cord blood stem cells.

Perivascular delivery of a nitric oxide donor inhibits neointimal hyperplasia in vein grafts implanted in the arterial circulation

OBJECTIVE

Nitric oxide has been reported to reduce intimal hyperplasia as a response to arterial injury. This study was designed to assess the possible effect of perivascular application of a nitric oxide donor on neointimal proliferation occurring in veins exposed to the dynamics of the arterial circulation in a hypercholesterolemic rabbit model.

METHODS

Autologous jugular vein grafts were implanted in the carotid circulation of 20 hypercholesterolemic rabbits. A mixture of a biodegradable polymer and the nitric oxide donor, spermine/nitric oxide, which releases nitric oxide with a half-life of 39 minutes, was applied periadventitially at the time of implantation. Controls were veins bathed in saline solution, polymer alone, and polymer plus the carrier vehicle spermine without nitric oxide. Animals (n = 5 in each group) were put to death on day 28 for morphometric analysis, cell count, and immunohistochemical staining.

RESULTS

Treatment with perivascular nitric oxide donor significantly decreased wall thickness (126 +/- 24 microm vs 208 +/- 45 microm, p = 0.0017) and area (124 +/- 22 microm2/microm vs 211 +/- 37 microm2/microm, p = 0.005). With the carrier vehicle spermine alone, there was a trend toward reduced intimal thickness, but the change was not statistically significant. In the grafts treated with nitric oxide donor, expression of insulin-like growth factor, fibroblast growth factor, thrombospondins, fibronectin, and tenascin was reduced.

CONCLUSION

The periadventitial delivery of nitric oxide donor produces a reduction of neointimal hyperplasia in veins implanted in the arterial circulation. The mechanism of action is not entirely clear, but the reduction cannot be explained on the basis of decreased cell proliferation alone. Other possibilities are modulation of protein synthesis of vascular smooth muscle cells and production of extracellular matrix components.

[Rapid determination of essential fatty acids of edible oils by conversion to their hydroxamic acids]

A simple and rapid HPLC method for the determination of essential fatty acids of edible oils was established. Oil samples were converted to their hydroxamic acids in a single step and analyzed without prior separation and purification. The chromatographic conditions were: Shim-pack CLC ODS, 5 microns, 150 mm x 6.0 mm i.d. column, 40 degrees C; MeOH: 0.02 mol/L NaH2PO4(pH 3.0) (81:19, V/V) as eluent and UV-213 nm detector. The linear range was 0.05-0.6 g/L, recovery was 96.93% and RSD was 1.80%(n = 4). The relative standard deviations for intra-day and inter-day assays were 1.24% and 1.62% respectively (n = 6). For 18:3, 18:2, 18:1, the difference between the derivatization yields from triglycerides and their methyl esters was almost one fold. That was confirmed by our recovery and determination results. The calibration curves for the oil samples should not be obtained from the derivatization of their methyl ester standards.

Differential distribution and subcellular localization of ryanodine receptor isoforms in the chicken cerebellum during development

The distribution of ryanodine receptor (RyR) isoforms was examined using isoform-specific monoclonal antibodies in the developing chicken brain, from E18 through adulthood, using light and electron microscopic immunocytochemistry. Monoclonal antibody 110F is specific for the alpha-skeletal muscle form of RyR, while monoclonal antibody 110E recognizes both the beta-skeletal muscle and cardiac isoforms, but does not distinguish between the two. Significant differences in the distribution of the alpha- and beta/cardiac forms were observed. Labeling for the alpha-form was restricted to cerebellar Purkinje neurons while the beta/cardiac form was observed in neurons throughout the brain. A major finding was the presence of labeling for the beta/cardiac in presynaptic terminals of the parallel fibers in the molecular layer and the mossy fiber terminals in the granular layer glomeruli in late development and during adulthood. Labeling for the beta/cardiac, but not the alpha-form, underwent a major redistribution in the cerebellum during the course of development. At 1 day of age, beta/cardiac labeling was present mainly in Purkinje neurons. From 1 day to 4 weeks, immunolabeling for the beta/cardiac form gradually disappeared from Purkinje neurons, but increased in granule cells. Within the molecular layer, the labeling pattern changed from being primarily within Purkinje dendrites to a more diffuse pattern. Electron microscopic examination of the cerebellar molecular layer of 2-week-old chicks revealed that beta/cardiac-labeling was mainly present in the axons and presynaptic processes of the parallel fibers. No developmental changes were observed in other brain regions. This study represents the first demonstration of ryanodine receptor immunoreactivity in presynaptic boutons and suggests that the ryanodine receptor may modulate neurotransmitter release through local regulation of intracellular calcium in the parallel fiber synapse.

Visualization of the distribution of autophosphorylated calcium/calmodulin-dependent protein kinase II after tetanic stimulation in the CA1 area of the hippocampus

Autophosphorylation of calcium/calmodulin-dependent protein kinase II (CaMKII) at threonine-286 produces Ca2+-independent kinase activity and has been proposed to be involved in induction of long-term potentiation by tetanic stimulation in the hippocampus. We have used an immunocytochemical method to visualize and quantify the pattern of autophosphorylation of CaMKII in hippocampal slices after tetanization of the Schaffer collateral pathway. Thirty minutes after tetanic stimulation, autophosphorylated CaM kinase II (P-CaMKII) is significantly increased in area CA1 both in apical dendrites and in pyramidal cell somas. In apical dendrites, this increase is accompanied by an equally significant increase in staining for nonphosphorylated CaM kinase II. Thus, the increase in P-CaMKII appears to be secondary to an increase in the total amount of CaMKII. In neuronal somas, however, the increase in P-CaMKII is not accompanied by an increase in the total amount of CaMKII. We suggest that tetanic stimulation of the Schaffer collateral pathway may induce new synthesis of CaMKII molecules in the apical dendrites, which contain mRNA encoding its alpha-subunit. In neuronal somas, however, tetanic stimulation appears to result in long-lasting increases in P-CaMKII independent of an increase in the total amount of CaMKII. Our findings are consistent with a role for autophosphorylation of CaMKII in the induction and/or maintenance of long-term potentiation, but they indicate that the effects of tetanus on the kinase and its activity are not confined to synapses and may involve induction of new synthesis of kinase in dendrites as well as increases in the level of autophosphorylated kinase.

Do nonasterid holoparasitic flowering plants have plastid genomes?

Past work involving the plastid genome (plastome) of holoparasitic plants has been confined to Scrophulariaceae (or Orobanchaceae) which have truncated plastomes owing to loss of photosynthetic and other genes. Nonasterid holoparasites from Balanophoraceae (Corynaea), Hydnoraceae (Hydnora) and Cytinaceae (Cytinus) were tested for the presence of plastid genes and a plastome. Using PCR, plastid 16S rDNA was successfully amplified and sequenced from the above three holoparasites. The sequence of Cytinus showed 121 single base substitutions relative to Nicotiana (8% of the molecule) whereas higher sequence divergence was observed in Hydnora and Corynaea (287 and 513 changes, respectively). Secondary structural models for these 16S rRNAs show that most changes are compensatory, thus suggesting they are functional. Probes constructed for 16S rDNA and for four plastid-encoded ribosomal protein genes (rps2, rps4, rps7 and rpl 16) were used in Southern blots of digested genomic DNA from the three holoparasites. Positive hybridizations were obtained using each of the five probes only for Cytinus. For Smal digests, all plastid gene probes hybridized to a common fragment ca. 20 kb in length in this species. Taken together, these data provide preliminary evidence suggestive of the retention of highly diverged and truncated plastid genome in Cytinus. The greater sequence divergence for 16S rDNA and the negative hybridization results for Hydnora and Corynaea suggests two possibilities: the loss of typically conserved elements of their plastomes or the complete absence of a plastome.

Inhibitory effect of 3'-untranslated region (3'-UTR) of human tissue-plasminogen activator (ht-PA) mRNA on its expression

A series of t-PA cDNA mutants containing different parts of 3'-UTR sequences have been constructed. In vitro translation of t-PA transcripts in rabbit reticulocyte lysates and its expression in COS-7 cells show that the 3'-UTR sequence has a very strong inhibitory effect on t-PA translation. The deletion of 3'-UTR results in 3-8-fold increase of t-PA expression. Further study shows that an AU-rich sequence of some 200 nt at 3' end of 3'-UTR is responsible for the translational inhibition. RNA stability experiment reveals that the AU-rich segment leads to a 3-fold decrease of t-PA mRNA stability. The insertion of this segment into the 3'-UTR of luciferase gene results in an obvious inhibition of Luc expression. A model is proposed for the regulation of t-PA expression.