New biomarker for lung cancer - focus on circSETD3

In order to explore the mechanism of gefitinib-acquired resistance in lung cancer, a new biomarker has been developed for early clinical diagnosis and intervention; human NSCLC (Non-Small Cell Lung Cancer) cell lines H292 (denoted as H292S) and PC9 (denoted as PC9S) were used to establish gefitinib-resistant NSCLC cell lines H292 and PC9 models. CCK-8 (Cell Counting Kit-8) method was used to test the drug resistance of the cells. circRNAs (circular RNAs) that were differentially expressed before and after resistance were screened by RNA sequencing technology. The effects of circSETD3 overexpression and interference on the sensitivity of gefitinib was observed to analyze the nuclear localization of circSETD3 and verify the interaction between circSETD3-miR-520h-ABCG2. The results showed that the most significant change in differential expression of human NSCLC cell lines before and after drug resistance was hsa_circ_0000567, that is, circSETD3, which is mainly present in the cytoplasm. In H292S and PC9S, compared with the negative control group, the cell proliferation ability of the overexpression group was significantly increased, and the apoptosis ability was significantly decreased. In H292R and PC9R, compared with the negative control group, the proliferation ability of the interference group was significantly decreased, and the apoptosis ability was significantly increased. Overexpression of circSETD3 to H292S and PC9S, the expression of ABCG2 increased significantly. Also, the expression of ABCG2 decreased significantly after transfection with miR-520h mimics. H292R and PC9R interfered with circSETD3, the expression of ABCG2 decreased significantly. Moreover, the expression of ABCG2 increased significantly after transfection with miR-520h inhibitor. In conclusion, circSETD3 can be used as a novel biomarker for lung cancer. It relieves miR-520h degradation of the transporter ABCG2 by down-regulating the miR-520h expression, causing gefitinib to be pumped out of the cell.

Shift-Twin Option in Eight-Layer Hexagonal Perovskite Niobates Ba8MNb6O24

Two new eight-layer hexagonal perovskites with the composition Ba₈MNb₆O₂₄ (M = Fe and Cu) are synthesized by solid-state reaction at 1350-1400 °C. Their crystal structures have been investigated using X-ray and electron diffractions as well as high-resolution transmission electron microscopy. Although both compounds have similar M²⁺ size, Ba₈FeNb₆O₂₄ and Ba₈CuNb₆O₂₄ adopt shifted and twinned structures, respectively. Through comparison with the reported shifted Ba₈MNb₆O₂₄ (M = Mn, Co, and Zn) and twinned Ba₈NiNb₆O₂₄ as well as inexistent Ba₈Mg(Nb/Ta)₆O₂₄, we elucidate that the twin-shift competition of Ba₈MNb₆O₂₄ family could be related with multiple chemical factors including tolerance factors, B-cationic size difference, entropy variation with B-cation and vacancy disorder, Jahn-Teller distortion, and FSO B-B d orbit interactions.

Implications of crop model ensemble size and composition for estimates of adaptation effects and agreement of recommendations

Climate change is expected to severely affect cropping systems and food production in many parts of the world unless local adaptation can ameliorate these impacts. Ensembles of crop simulation models can be useful tools for assessing if proposed adaptation options are capable of achieving target yields, whilst also quantifying the share of uncertainty in the simulated crop impact resulting from the crop models themselves. Although some studies have analysed the influence of ensemble size on model outcomes, the effect of ensemble composition has not yet been properly appraised. Moreover, results and derived recommendations typically rely on averaged ensemble simulation results without accounting sufficiently for the spread of model outcomes. Therefore, we developed an Ensemble Outcome Agreement (EOA) index, which analyses the effect of changes in composition and size of a multi-model ensemble (MME) to evaluate the level of agreement between MME outcomes with respect to a given hypothesis (e.g. that adaptation measures result in positive crop responses). We analysed the recommendations of a previous study performed with an ensemble of 17 crop models and testing 54 adaptation options for rainfed winter wheat (Triticum aestivum L.) at Lleida (NE Spain) under perturbed conditions of temperature, precipitation and atmospheric CO2 concentration. Our results confirmed that most adaptations recommended in the previous study have a positive effect. However, we also showed that some options did not remain recommendable in specific conditions if different ensembles were considered. Using EOA, we were able to identify the adaptation options for which there is high confidence in their effectiveness at enhancing yields, even under severe climate perturbations. These include substituting spring wheat for winter wheat combined with earlier sowing dates and standard or longer duration cultivars, or introducing supplementary irrigation, the latter increasing EOA values in all cases. There is low confidence in recovering yields to baseline levels, although this target could be attained for some adaptation options under moderate climate perturbations. Recommendations derived from such robust results may provide crucial information for stakeholders seeking to implement adaptation measures.

Substitution-Induced Structure Evolution and Zn2+/Ga3+ Ordering in "114" Oxides MAZn2Ga2O7 ( M = Ca2+, Sr2+; A = Sr2+, Ba2+)

The "114" oxides LnBa(Co/Fe)₄O_7+δ represent a new family of materials that exhibits intriguing physical properties, including geometrically frustrated magnetism, oxygen storage, and magnetoelectric couplings. Various chemical substitutions have been conducted to modify their crystal and magnetic structures as well as physical properties. However, the principles beneath the substitution-induced structural evolution and charge/cationic ordering have not yet been understood. Thus, in this contribution, two complete solid solutions of MAZn₂Ga₂O₇ ( M = Ca²⁺, Sr²⁺; A = Sr²⁺, Ba²⁺) were designed, synthesized, and characterized by Rietveld refinements based on high-resolution X-ray diffraction (XRD) and neutron diffraction (ND) data. The structure symmetry of MAZn₂Ga₂O₇ is determined by the cationic size mismatch between M and A cations that can be defined by the tolerance factor t, i.e., symmetry transitions from P6₃ mc ( t > 0.87) to P31 c (0.87 > t > 0.75) and to Pna2₁ ( t < 0.75) were observed for MAZn₂Ga₂O₇, associated with the rotation of T1O₄ tetrahedra in the triangular layers. The Zn²⁺/Ga³⁺ ordering at T sites is also a consequence of the increase or decrease of the average sizes of M and A cations. A small concentration of interstitial oxygen ions can be obtained in Sr₂Zn_{2- x}Ga_{2+ x}O_{7+ x/2} ( x = 0.1, 0.2); however, no oxygen ionic conduction was observed at high temperatures, indicating the migration ability of the interstitial oxygen was very limited.

8-Layer Shifted Hexagonal Perovskite Ba8MnNb6O24: Long-Range Ordering of High-Spin d5 Mn2+ Layers and Electronic Structure

A new 8-layer shifted hexagonal perovskite Ba₈MnNb₆O₂₄ has been synthesized in air, featuring unusual long-range B-cation ordering with single octahedral high-spin d⁵ Mn²⁺ layers separated by ∼1.9 nm within the corner-sharing octahedral d⁰ Nb⁵⁺ host, analogous to Ba₈(Zn/Co)Nb₆O₂₄. The large size and charge differences between high-spin Mn²⁺ and Nb⁵⁺, as well as the out-of-center distortion of NbO₆ octahedra associated with the bonding covalence and second-order Jahn-Teller effect of Nb⁵⁺, drive long-range cationic ordering, thus stabilizing Ba₈MnNb₆O₂₄. The Ba₈MnNb₆O₂₄ pellet exhibits a high dielectric permittivity, ε_r ∼ 38, and a large temperature coefficient of resonant frequency, τ_f ∼ 20 ppm/K, but a dielectric loss ( Qf ∼ 987 GHz) and conductivity (∼10^-8-10^-3 S/cm within 473-1173 K) much higher than those of Ba₈ZnNb₆O₂₄. Electronic structures from density functional theory calculations reveal that Ba₈MnNb₆O₂₄ is a Mott insulator in contrast with the charge-transfer insulator nature of Ba₈ZnNb₆O₂₄, and they confirm that the off-center distortion of Nb⁵⁺ contributes to stabilization of the 8-layer ordered shifted structure. The contrast between conductivity and dielectric loss of Ba₈MnNb₆O₂₄ and Ba₈ZnNb₆O₂₄ is understood based on the electronic structure that depends on high-spin d⁵ Mn²⁺ and d¹⁰ Zn²⁺ cations. The hopping of 3d valence electrons in high-spin Mn²⁺ to Nb⁵⁺ 4d conduction bands over a small gap (∼2.0 eV) makes Ba₈MnNb₆O₂₄ more conductive than Ba₈ZnNb₆O₂₄, where the electrons are conducted via the hopping of a lattice O 2p valence electron to the Nb⁵⁺ 4d conduction bands over a larger gap (∼3.9 eV). The high microwave dielectric loss of BMN may be mainly ascribed to the half-filled Mn 3d orbits, which is understood based on the softened infrared modes that increase the lattice vibration anharmonicity as well as the resonant spin excitation of unpaired d electrons.

Safety and efficacy evaluation of laparoscopy in colorectal cancer with liver metastasis

OBJECTIVE

To study the safety and efficacy of simultaneous completion of colorectal cancer resection and liver metastasis resection by total laparoscopy.

PATIENTS AND METHODS

In the observation group, 40 patients with colorectal cancer combined with liver metastasis (CRCLM) were selected to receive total laparoscopic surgery. At the same time, 40 cases were selected for laparoscopic resection of colorectal cancer and hepatic resection as control group.

RESULTS

The outcomes of the two methods in the treatment of CRCLM were compared. The results showed that the difference in surgery time between the two groups was not statistically significant (p>0.05). The blood loss, drainage tube retention time and anal exhaust recovery time in the observation group were significantly less than those in control group (p<0.05). No significant difference in completion rate was found between the two groups (p>0.05); the prevalence rate of complications in the observation group was significantly lower than that in control group (p<0.05). No significant differences in the median survival period and the survival rate at 1 year, 2 years and 3 years after surgery were found between the two groups (p>0.05).

CONCLUSIONS

The outcomes of total laparoscopy in the treatment of CRCLM are not inferior to open surgery.

[Assessment and surgical treatment for 58 substernal goiter]

Objective: To investigate the diagnosis and treatment of substernal goiter. Methods: A total of 58 cases with substernal goiters undergoing surgery between January 2005 and December 2015 were analysed retrospectively. There were 10 males and 48 females and their age ranged from 38 to 82 years with a median age of 58 years. According to enhanced CT and clinical signs of substernal goiters, there were 40 cases for typeⅠ, 17 cases for type Ⅱ, and 1 case for type Ⅲ. Results: Patients with typeⅠand Ⅱ substernal goiters (8 cases of papillary carcinoma) underwent low neck and collar-type incision, and patients with type Ⅲ substernal goiters received carotid chest surgery. The use of harmonic scalpel in sternal goiter surgery provided with clearer surgical field, less bleeding. All the operations were successful, and recurrent laryngeal nerve was visually identified in all patients. Postoperative complications included trachyphonia (2 cases), without difficult breathing and tracheal stenosis. Conclusions: Enhanced CT is the best means of preoperatively assessment of substernal goiter. It is feasible to treat patients with typeⅠand Ⅱ substernal goiters by lower neck and collar-type incision. Use of harmonic scalpel in substernal goiter surgery can reduce operation time and bleeding.

Linking genomic reorganization to tumor initiation via the giant cell cycle

To investigate the mechanisms underlying our recent paradoxical finding that mitotically incapacitated and genomically unstable polyploid giant cancer cells (PGCCs) are capable of tumor initiation, we labeled ovarian cancer cells with α-tubulin fused to green fluorescent protein, histone-2B fused to red fluorescent protein and FUCCI (fluorescent ubiquitination cell cycle indicator), and tracked the spatial and time-dependent change in spindle and chromosomal dynamics of PGCCs using live-cell fluorescence time-lapse recording. We found that single-dose (500 nm) treatment with paclitaxel paradoxically initiated endoreplication to form PGCCs after massive cell death. The resulting PGCCs continued self-renewal via endoreplication and further divided by nuclear budding or fragmentation; the small daughter nuclei then acquired cytoplasm, split off from the giant mother cells and acquired competency in mitosis. FUCCI showed that PGCCs divided via truncated endoreplication cell cycle (endocycle or endomitosis). Confocal microscopy showed that PGCCs had pronounced nuclear fragmentation and lacked expression of key mitotic proteins. PGCC-derived daughter cells were capable of long-term proliferation and acquired numerous new genome/chromosome alterations demonstrated by spectral karyotyping. These data prompt us to conceptualize a giant cell cycle composed of four distinct but overlapping phases, initiation, self-renewal, termination and stability. The giant cell cycle may represent a fundamental cellular mechanism to initiate genomic reorganization to generate new tumor-initiating cells in response to chemotherapy-induced stress and contributes to disease relapse.

Use of crop simulation modelling to aid ideotype design of future cereal cultivars

A major challenge of the 21st century is to achieve food supply security under a changing climate and roughly a doubling in food demand by 2050 compared to present, the majority of which needs to be met by the cereals wheat, rice, maize, and barley. Future harvests are expected to be especially threatened through increased frequency and severity of extreme events, such as heat waves and drought, that pose particular challenges to plant breeders and crop scientists. Process-based crop models developed for simulating interactions between genotype, environment, and management are widely applied to assess impacts of environmental change on crop yield potentials, phenology, water use, etc. During the last decades, crop simulation has become important for supporting plant breeding, in particular in designing ideotypes, i.e. 'model plants', for different crops and cultivation environments. In this review we (i) examine the main limitations of crop simulation modelling for supporting ideotype breeding, (ii) describe developments in cultivar traits in response to climate variations, and (iii) present examples of how crop simulation has supported evaluation and design of cereal cultivars for future conditions. An early success story for rice demonstrates the potential of crop simulation modelling for ideotype breeding. Combining conventional crop simulation with new breeding methods and genetic modelling holds promise to accelerate delivery of future cereal cultivars for different environments. Robustness of model-aided ideotype design can further be enhanced through continued improvements of simulation models to better capture effects of extremes and the use of multi-model ensembles.

Physical activity, body mass index and mental health in Chinese adolescents: a population based study

AIM

The aim of the present study was to examine the association between physical activity, BMI level and mental health among Chinese adolescents.

METHODS

Three thousand ninety-six adolescents aged 11 to 13 were analyzed from 6 middle schools of Xuzhou. Physical activity level was measured using self-designed questionnaires. BMI was calculated according to the results of these students' physical examinations. Anxiety symptoms were assessed by using the Screen for Child Anxiety Related Emotional Disorder, depression via the Children's Depression Inventory. Data were analyzed using chi-square test and logistic regression.

RESULTS

Adolescents' self-reported rate of insufficient physical activity was 58.1%. The overweight and obesity rates were 18.4%, 16.0%. The point prevalence rates on anxiety and depression were 15.2%, 11.5%. Insufficient physical activity was positively associated with anxiety and depression (OR [95%CI]: 1.31 [1.06-1.63]; 1.33 [1.04-1.70]). Obesity was positively associated with depression (OR [95%CI]: 1.48 [1.10-2.00]). IS-OB was positively associated with anxiety and depressive (OR [95%CI]: 1.71 [1.19-2.45]; 1.99 [1.33-2.97]).

CONCLUSION

Physical inactivity and overweight/obesity were negatively association with mental health of adolescents, respectively. Meanwhile, to explore the combined effects of physical inactivity and obesity would increase the risk of anxiety and depression in adolescents.

Synthesis of poly (3-hydroxybutyrate-co-3-hydroxyoctanoate) by a Sinorhizobium fredii strain

AIMS

The potential of a Sinorhizobium fredii strain to produce a copolymer from glucose and sodium dodecanoate substrates was investigated.

METHODS AND RESULTS

Using an orthogonal design in a flask-shaker culture system, the vital regulation conditions for copolymer synthesis were optimized. These optimal results were applied to further studies in a two-stage fed-batch fermentation with a 10-l fermentor. When the biomass approached 33.5 g l(-1) dry cells at 35 h, 7 mmol l(-1) sodium dodecanoate was added into the broth to trigger the copolymer synthesis. After further culturing for 3 h, the copolymer product could be 17.14 g l(-1). The molecular structure of the copolymer was determined to be a poly (3-hydroxybutyrate-co-3-hydroxyoctanoate) [P (HB-HO)] by nuclear magnetic resonance. The content of HB and HO in P (HB-HO) was 79.2% (w/w) and 20.8% (w/w) respectively. The molecular weight of the P (HB-HO) was measured as 1.85 x 10(5) Da by a viscosity method.

CONCLUSION

The results demonstrated that the S. fredii strain used could be a potential candidate for the industrial production of the copolymer.

SIGNIFICANCE AND IMPACT OF THE STUDY

Some basic fermentation parameters were acquired through the fed-batch culturing experiments and they should be applicable in developing large-scale fermentation technologies for producing the P (HB-HO) copolymers.

Differential roles of neuronal and endothelial nitric oxide synthases during carrageenan-induced inflammatory hyperalgesia

The present study investigated the role of neuronal nitric oxide synthase (nNOS) in carrageenan-induced inflammatory pain by combining genomic and pharmacological strategies. Intrathecal injection of the nNOS inhibitor 7-nitroindazole dose-dependently inhibited carrageenan-induced thermal hyperalgesia in both early and late phases in wild-type mice. However in nNOS knockout mice, carrageenan-induced thermal hyperalgesia remained intact in the early phase but was reduced in the late phase. Spinal Ca2+ -dependent nitric oxide synthase (NOS) activity in nNOS knockout mice was significantly lower than that in wild-type mice. Following carrageenan injection, although the spinal Ca2+ -dependent NOS activity in both wild-type and knockout mice increased, the enzyme activity in nNOS knockout mice reached a level similar to that in wild-type mice. On the other hand, no significant difference in spinal Ca2+ -independent NOS activity was noted between wild-type and nNOS knockout mice before and after carrageenan injection. Furthermore, intrathecal administration of the endothelial NOS (eNOS) inhibitor L-N5-(1-iminoethyl)-ornithinein nNOS knockout mice inhibited the thermal hyperalgesia in both early and late phases, though this inhibitor had no effect in wild-type mice. Meanwhile, Western blot showed that eNOS expression in the spinal cord of nNOS knockout mice was up-regulated compared with wild-type mice; immunohistochemical staining showed that the spinal eNOS was mainly distributed in superficial laminae of the dorsal horn. Finally, double staining with confocal analysis showed that the enhanced spinal eNOS was expressed in astrocytes, but not in neurons. Our current results indicate that nNOS plays different roles in the two phases of carrageenan-induced inflammatory pain. In this model, enhanced spinal eNOS appears to compensate for the role of nNOS in nNOS knockout mice.

Efficient preparation of L-cysteic acid and its esters

L-Cysteic acid and its esters were prepared in good yields from the oxidation of L-cystine by chlorine in water and in alcohols. When the reaction was carried out in alcohols the corresponding esters were produced.

Evidence of neuronal excitatory amino acid carrier 1 expression in rat dorsal root ganglion neurons and their central terminals

The expression and distribution of the neuronal glutamate transporter, excitatory amino acid carrier-1 (EAAC1), are demonstrated in the dorsal root ganglion neurons and their central terminals. Reverse transcriptase-polymerase chain reaction shows expression of EAAC1 mRNA in the dorsal root ganglion. Immunoblotting analysis further confirms existence of EAAC1 protein in this region. Immunocytochemistry reveals that approximately 46.6% of the dorsal root ganglion neurons are EAAC1-positive. Most EAAC1-positive neurons are small and around 250-750 microm2 in surface area, and some co-label with calcitonin gene-related peptide (CGRP) or isolectin IB4. In the spinal cord, EAAC-1 immunoreactive small dot- or patch-like structures are mainly localized in the superficial dorsal horn, and some are positive for CGRP or labeled by isolectin IB4. Unilateral dorsal rhizotomy experiments further show that EAAC1 immunoreactivity is less intense in superficial dorsal horn on the side ipsilateral to the dorsal rhizotomy than on the contralateral side. The results indicate the presence of EAAC1 in the dorsal root ganglion neurons and their central terminals. Our findings suggest that EAAC1 might play an important role in transmission and modulation of nociceptive information via the regulation of pre-synaptically released glutamate.

Knockdown of spinal cord postsynaptic density protein-95 prevents the development of morphine tolerance in rats

The activation of spinal cord N-methyl-D-aspartate (NMDA) receptors and subsequent intracellular cascades play a pivotal role in the development of opioid tolerance. Postsynaptic density protein-95 (PSD-95), a molecular scaffolding protein, assembles a specific set of signaling proteins around NMDA receptors at neuronal synapses. The current study investigated the possible involvement of PSD-95 in the development of opioid tolerance. Opioid tolerance was induced by intrathecal injection of morphine sulfate (20 microg/10 microl) twice a day for 4 consecutive days. Co-administration of morphine twice daily and PSD-95 antisense oligodeoxynucleotide (50 microg/10 microl) once daily for 4 days not only markedly reduced the PSD-95 expression and its binding to NMDA receptors in spinal cord but also significantly prevented the development of morphine tolerance. In contrast, co-administration of morphine twice daily and PSD-95 missense oligodeoxynucleotide (50 microg/10 microl) once daily for 4 days did not produce these effects. The PSD-95 antisense oligodeoxynucleotide at the doses we used did not affect baseline response to noxious thermal stimulation or locomotor function. The present study indicates that the deficiency of spinal cord PSD-95 attenuates the development of opioid tolerance. These results suggest that PSD-95 might be involved in the central mechanisms of opioid tolerance and provide a possible new target for prevention of development of opioid tolerance.

Intact carrageenan-induced thermal hyperalgesia in mice lacking inducible nitric oxide synthase

To date, the exact role of inducible nitric oxide synthase (iNOS) in inflammatory pain remains controversial. In the present study, we combined a pharmacological strategy (using a selective iNOS inhibitor) with a genomic strategy (using mice lacking the iNOS gene) to address the function of iNOS in the central mechanism of carrageenan-induced persistent inflammatory pain. In the wild type mice, intrathecal administration of L-N(6)-(1-iminoethyl)-lysine, a selective iNOS inhibitor, significantly inhibited thermal hyperalgesia in the late phase but not in the early phase of carrageenan inflammation. Moreover, iNOS mRNA expression in the lumbar enlargement segments of the spinal cord was dramatically induced at 24 h (late phase) after injection of carrageenan into a hind paw. Interestingly, targeted disruption of iNOS gene did not affect carrageenan-induced thermal hyperalgesia in either the early (2-6 h) or late phase. In the lumbar enlargement segments of iNOS knockout mice, nitric oxide synthase (NOS) enzyme activity remained at a similar level to that of the wild type mice at 24 h after carrageenan injection. We found that intrathecal administration of 7-nitroindazole (a selective neuronal NOS inhibitor), but not L-N(5)-(1-iminoethyl)-ornithine (a selective endothelial NOS inhibitor), significantly reduced carrageenan-induced thermal hyperalgesia in both the early phase and the late phase in iNOS knockout mice. We also found that expression of neuronal NOS but not endothelial NOS in the lumbar enlargement segments was significantly increased in iNOS knockout mice compared with wild type mice at 24 h after carrageenan injection. Our results indicate that neuronal NOS might compensate for the function of iNOS in the late phase of carrageenan-induced inflammatory pain in iNOS knockout mice. This suggests that iNOS may be sufficient, but not essential, for the late phase of the carrageenan-induced thermal hyperalgesia.

Modulation of smooth muscle phenotype in vitro by homologous cell substrate

We have developed a novel cell culture system that supports the shortening of smooth muscle cells. Primary rat airway smooth muscle cells were plated on an ethanol-fixed, confluent monolayer of homologous smooth muscle cells (homologous cell substrate, HCS). Cells grown on HCS exhibited morphological and functional characteristics consistent with a differentiated phenotype. Cells on HCS were spindle shaped with a well-defined long axis, whereas cells grown on glass were larger and irregularly shaped. Smooth muscle-specific alpha-actin immunostained diffusely in cells on HCS, whereas it appeared as stress fibers in cells on glass. Agonists recruited a greater fraction of HCS cells to contract, resulting in greater changes in cell area or length on average, but the maximal capacity of shortening of individual cells was similar between the groups. Unlike cells on glass, cells on HCS shortened to methacholine. HCS was reversible and persisted over several passages. Agonists stimulated intracellular Ca(2+) oscillations in cells on HCS, whereas they elicited biphasic peak and plateau transients in cells on glass. HCS modulates smooth muscle cell phenotype in vitro.

Role of postsynaptic density protein-95 in the maintenance of peripheral nerve injury-induced neuropathic pain in rats

Our previous work has demonstrated that postsynaptic density protein-95, a molecular scaffolding protein that binds and clusters N-methyl-D-aspartate receptors at neuronal synapses, plays an important role in the development of peripheral nerve injury-induced neuropathic pain. The current study further investigated the possible involvement of postsynaptic density protein-95 in the maintenance of neuropathic pain. Mechanical and thermal hyperalgesia were induced within 3 days and maintained for 15 days or longer after unilateral injury to the fifth lumbar spinal nerve. The rats injected intrathecally with postsynaptic density protein-95 antisense oligodeoxynucleotide every 24 h for 4 days from day 7 to day 10 post-surgery exhibited not only a marked decrease in spinal cord postsynaptic density protein-95 protein expression but also a significant reduction in mechanical and thermal hyperalgesia on day 11 post-surgery. The rats injected with sense oligodeoxynucleotide did not display these changes. However, in the rats without nerve injury, postsynaptic density protein-95 antisense oligodeoxynucleotide given intrathecally every 24 h for 4 days did not affect responses to mechanical and thermal stimulation. In addition, postsynaptic density protein-95 antisense oligodeoxynucleotide did not change locomotor activity of experimental animals. Our results indicate that the deficiency of postsynaptic density protein-95 protein in the spinal cord significantly attenuates nerve injury-induced mechanical and thermal hyperalgesia during both the development and maintenance of chronic neuropathic pain. These results suggest that postsynaptic density protein-95 might be involved in the central mechanisms of chronic neuropathic pain and provide a novel target for development of new pain therapies.

Effect of greenbugs (Homoptera: Aphididae) on yield loss of winter wheat

The effect of greenbug, Schizaphis graminum (Rondani), feeding on the yield of four winter wheat cultivars commonly grown in Oklahoma was studied. Cultivars tested were 'Karl', a recent derivative 'Karl-92', and '2163', all greenbug-susceptible cultivars; and 'TAM-110', a cultivar with resistance to biotype E greenbugs. The objectives were to determine the effect of different greenbug densities during fall and spring on yield of winter wheat, and to develop mathematical models to quantify the effect of greenbugs on yield loss. The intensity of greenbug infestations achieved in plots by artificial infestation varied among years and growing seasons within a year, but was generally sufficient to cause a reduction in yield. Among yield components, the number of heads per square meter and the number of seeds per head were frequently negatively correlated with the accumulated number of greenbug-days per tiller. Seed weight was rarely affected by greenbug infestation. A regression model estimated yield loss for greenbug-susceptible cultivars at 0.51 kg/ha loss of yield per greenbug-day in years with near normal precipitation, and a loss of 1.17 kg/ha under severe drought conditions. The susceptible winter wheat cultivars exhibited similar yield loss in relation to the intensity of greenbug infestation, as indicated by a common slope parameter in the regression model. Results suggest that the model is robust for predicting yield loss for susceptible cultivars.

Knockdown of PSD-95/SAP90 delays the development of neuropathic pain in rats

Our previous work has shown that PSD-95/SAP90 is required for NMDA receptor-mediated thermal hyperalgesia. To address the role of PSD-95/SAP90 in chronic pain, the present study investigated the effect of the deficiency of PSD-95/SAP90 on nerve injury-induced neuropathic pain. Following unilateral L5 spinal nerve injury, mechanical and thermal hyperalgesia developed within 3 days and persisted for 9 days or longer on the injured side. The intrathecal administration of antisense oligodeoxynucleotide specifically against PSD-95/SAP90, but not sense or missense oligodeoxynucleotide, dose-dependently delayed the onset of tactile allodynia and thermal hyperalgesia. These results suggest that PSD-95/SAP90 might be involved in the central mechanisms of the development of chronic neuropathic pain.

Selective binding of the cyano group in acrylonitrile adsorption on Si(100)-2 x 1

The covalent binding of acrylonitrile (CH(2)=CH-C triple bond N) and the formation of a C=C-C=N structure on Si(100) have been investigated using high-resolution electron energy loss spectroscopy (HREELS), X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and density functional theory (DFT) calculations. For chemisorbed acrylonitrile, the absence of nu(C triple bond N) at 2245 cm(-1) and the appearance of nu(C=N) at 1669 cm(-1) demonstrate that the cyano group directly participates in the interaction with Si(100), which is further supported by XPS and UPS observations. Our experimental results and DFT calculations unambiguously demonstrate a [2 + 2] cycloaddition mechanism for acrylonitrile chemisorption on Si(100) through the binding of C triple bond N to Si dimers. The resulting chemisorbed monolayer with a C=C-C=N skeleton can serve as a precursor for further chemical syntheses of multilayer organic thin films in a vacuum and surface functionalization for in situ device fabrication.

Role of excitatory amino acid transporter 1 in neonatal rat neuronal damage induced by hypoxia-ischemia

The role of excitatory amino acid transporter 1 in neonatal rat neuronal damage was studied following hypoxia-ischemia. To induce hypoxia-ischemia injury, rats on postnatal day 7 were exposed to 8 % oxygen for 2 h following unilateral common carotid artery ligation. According to brain damage scoring based on Cresyl Violet staining, the neuronal damage time-dependently changed in the ischemic regions following hypoxia-ischemia. Immunohistochemical studies showed that excitatory amino acid transporter 1 expression was mainly observed in the cerebral cortex ipsilateral to common carotid artery ligation and markedly increased at 24 h and 48 h following hypoxia-ischemia. Combined with confocal laser scanning microscopic analysis, double staining showed that excitatory amino acid transporter 1 positive staining appeared in neurons as well as astrocytes after hypoxia-ischemia. Most excitatory amino acid transporter 1 positive staining cells exhibited regular morphological characteristics and only a few were double-stained by terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick-end labeling. Down-regulation of excitatory amino acid transporter 1 expression by intraventricular administration of specific antisense oligonucleotide exacerbated neuronal damage in hypoxia-ischemia brain. These results suggest that the increase of excitatory amino acid transporter 1 expression may be involved in a pathophysiological process of hypoxia-ischemia brain damage and may reflect a self-compensative mechanism for protecting neurons from further injury.

Pressure cycling technology: a novel approach to virus inactivation in plasma

BACKGROUND

Hydrostatic-pressure virus inactivation is a novel approach to the inactivation of pathogens in plasma and blood-derived components, that retains the therapeutic properties of these products.

STUDY DESIGN AND METHODS

A custom-built apparatus was used to pressurize human plasma samples spiked with lambda phage. Phage titer and plasma protein activities were monitored after pressure treatment.

RESULTS

Pressure-mediated inactivation of lambda phage was found to be an effective means for virus inactivation, particularly when performed at near-zero (0 degrees C) temperatures, rather than at temperatures above 20 degrees C and below -40 degrees C. The efficiency of inactivation was improved by an increase in applied pressure and repeated cycling from atmospheric to high pressure. In contrast, activities of plasma proteins alkaline phosphatase and total amylase did not vary with temperature and remained within 29 percent and 6 percent, respectively, of starting values after the same pressure treatments. By combining cycling, near-zero temperatures, and high pressure, phage titers in serum were reduced approximately 6 log after 10 to 20 minutes of treatment. Activities of plasma proteins IgG, IgM, and factor X were at 104 percent, 89 percent, and 80 percent, respectively, of starting values after 20 minutes of the same temperature and pressure treatment.

CONCLUSION

High-pressure procedures may be useful for the inactivation of viruses in blood and other protein-containing components.

A bioseparation apparatus with high-pressure fluid injection and fluid sampling

A novel apparatus in which fluids may be injected and sampled at high pressure is described. Bioseparation applications of the apparatus were demonstrated in three model systems: (1) lambdaDNA was eluted under pressure from an anion exchange column into a low-salt (0.25 M) buffer, thereby eliminating conventional time-consuming desalting procedures required for downstream analysis of the DNA; (2) RNA was separated under pressure from a RNA/DNA mixture, thereby enabling rapid differential preparation of nucleic acids; and (3) an antibody was purified from a protein mixture by affinity capture at one pressure and dissociation from the antigen binding partner at a second pressure, thereby enabling the immunoreactivities of both antibody and antigen to be preserved during the separation process.

Hypoxia-ischemia altered expression of glutamate transporter EAAT1 in neonatal rat brain

AIM

To observe altered expression of glutamate transporter EAAT1 after hypoxia-ischemia (H-I) in newborn rat brain.

METHODS

Expression levels of EAAT1 were detected with immunohistochemistry method.

RESULTS

EAAT1 was a little expressed in cerebral cortex at sham-operated group [(36 +/- 10) cells/slice]. Its expression in cerebral cortex increased at 24 h and 48 h following H-I [(314 +/- 162) cells/slice and (431 +/- 149) cells/slice, respectively], and recovered to control level at 72 h following H-I [(52 +/- 8) cells/slice]. The expression of EAAT1 in the ipsilateral cortex to common carotid artery (CCA) ligation was higher than that in the contralateral cortex.

CONCLUSION

After H-I, the expression of EAAT1 had a temporal change in cerebral cortex of newborn rat, and was mainly located in the ipsilateral cortex to CCA ligation.

A CCHC metal-binding domain in Nanos is essential for translational regulation

The Drosophila Nanos protein is a localized repressor of hunchback mRNA translation in the early embryo, and is required for the establishment of the anterior-posterior body axis. Analysis of nanos mutants reveals that a small, evolutionarily conserved, C-terminal region is essential for Nanos function in vivo, while no other single portion of the Nanos protein is absolutely required. Within the C-terminal region are two unusual Cys-Cys-His-Cys (CCHC) motifs that are potential zinc-binding sites. Using absorption spectroscopy and NMR we demonstrate that the CCHC motifs each bind one equivalent of zinc with high affinity. nanos mutations disrupting metal binding at either of these two sites in vitro abolish Nanos translational repression activity in vivo. We show that full-length and C-terminal Nanos proteins bind to RNA in vitro with high affinity, but with little sequence specificity. Mutations affecting the hunchback mRNA target sites for Nanos-dependent translational repression were found to disrupt translational repression in vivo, but had little effect on Nanos RNA binding in vitro. Thus, the Nanos zinc domain does not specifically recognize target hunchback RNA sequences, but might interact with RNA in the context of a larger ribonucleoprotein complex.

Radiation effects on late cytopathological parameters in the murine lens relative to particle fluence

Lenses of mice irradiated with 250 MeV protons, 670 MeV/amu 20Ne, 600 MeV/amu 56Fe, 600 MeV/amu 93Nb and 593 MeV/amu 139La ions were evaluated by analyzing cytopathological indicators which have been implicated in the cataractogenic process. The LETs ranged from 0.40 keV/micrometer to 953 keV/micrometer and fluences from 1.31 10(3)/mm2 to 4.99 x 10(7)/mm2. 60Co gamma-rays were used as the reference radiation. The doses ranged from 10 to 40 cGy. The lenses were assessed 64 weeks post irradiation in order to observe the late effects of LET and dose on the target cell population of the lens epithelium. Our study shows that growth dependent pathological changes occur at the cellular level as a function of dose and LET. The shapes of the RBE-LET and RBE-dose curves are consistent with previous work on eye and other biological systems done in both our laboratory and others. The RBEmax's were estimated, for the most radiation cataract related cytological changes, MN frequency and MR disorganization, by calculating the ratio of the initial slopes of dose effect curve for various heavy ions to that of 60Co gamma-ray. For each ion studied, the RBEmax derived from micronucleus (MN) frequency is similar to that derived from meridional row (MR) disorganization, suggesting that heavy ions are equally efficient at producing each type of damage. Furthermore, on a per particle basis (particle/cell nucleus), both MN frequency and MR disorganization are LET dependent indicating that these classic precataractogenic indicators are multi-gene effects. Poisson probability analysis of the particle number traversing cell nuclei (average area = 24 micrometers2) suggested that single nuclear traversals determine these changes. By virtue of their precataractogenic nature the data on these endpoints intimate that radiation cataract may also be the consequence of single hits. In any case, these observations are consistent with the current theory of the mechanism of radiation cataractogenesis, which proposes that genomic damage to the epithelial cells surviving the exposure is responsible for opacification.

[Analysis of the acetylcholine action on the electrical activities of pancreatic islet B-cells in mice]

Intracellular potential recording and extracellular microiontophoretic techniques were used to study the acetylcholine (ACh) action on the electrical activities of pancreatic islet B-cells in mice. The B cell membrane potential was decreased (5-10 mV) and the spikes were increased (11-17/30 s) by the ACh microinotophoresis. These effects were dependent on glucose and completely blocked by atropine. However, pirenzepine could attenuate the electrical activity by approximately 70%. The ACh-induced membrane depolarization was Ca(2+)-independent and blocked by TTX. But the effect of ACh on spikes was Ca(2+)-dependent and not blocked by verapamil. The results showed that ACh action in the enhancement of glucose-dependent electrical activities of B-cell were mediated by muscarinic receptor, mainly by subtype M1. Then TTX-sensitive Na channel and verapamil-insensitive Ca channel were activated by M1 receptors. Na+ influx resulted in membrane depolarization and Ca2+ influx enhanced spike discharges.

The influence of dose, dose-rate and particle fragmentation on cataract induction by energetic iron ions

Because activities in space necessarily involve chronic exposure to a heterogeneous charged particle radiation field it is important to assess the influence of dose-rate and the possible modulating role of heavy particle fragmentation on biological systems. Using the well-studied cataract model, mice were exposed to plateau 600 MeV/amu 56Fe ions either as acute or fractionated exposures at total doses of 5 - 504 cGy. Additional groups of mice received 20, 360 and 504 cGy behind 50 mm of polyethylene, which simulates body shielding. The reference radiation consisted of 60Co gamma radiation. The animals were examined by slit lamp biomicroscopy over their three year life spans. In accordance with our previous observations with heavy particles, the cataractogenic potential of the 600 MeV/amu 56Fe ions was greater than for low-LET radiation and increased with decreasing dose relative to gamma-rays. Fractionation of a given dose of 56Fe ions did not reduce the cataractogenicity of the radiation compared to the acute regimen. Fragmentation of the beam in the polyethylene did not alter the cataractotoxicity of the ions, either when administered singly or in fractions.

[Transportation trends after rat renal intracapsular injection of Salvia miltiorrhizae]

The concentration of Salvia miltiorrhizae (SM) was detected at different time after renal intracapsular injection in S.D rats. It showed that SM concentration was higher in kidney than in plasma (P < 0.05). SM concentration in kidney increased gradually, it reached the peak at 24 hour and still remained in higher level at 48 hour. The SM injected in renal capsule could be passively transported to renal tissue and maintained at a high level. This result demonstrated that renal intracapsular injection could be applied as an important therapeutical method for different renal disease.

Accelerated heavy ions and the lens. IX. Late effects of LET and dose on cellular parameters in the murine lens

Lenses of mice irradiated with 250 MeV protons, 670 MeV/amu 20Ne, 600 MeV/amu 56Fe, 350 MeV/amu 56Fe, 600 MeV/amu 93Nb or 593 MeV/amu 139La ions were evaluated by analysing cytopathological indicators which have been implicated in the cataractogenic process. The LETs ranged from 0.39 to 953 keV/microns and the fluences from 1.31 x 10(3)/mm2 to 5.12 x 10(7)/mm2. The lenses were assessed 64 weeks post-irradiation in order to observe the late effects of LET and dose on the target cell population of the lens' epithelium. Our studies showed that growth-dependent pathological changes occurred at the cellular level as a function of dose and LET. For a given particle dose, as the LET rose, the number of abnormal mitotic figures, micronuclei frequency, and the disorganization of meridional rows increased to a maximum and then reached a plateau or decreased. For particles of the same LET, the severity of meridional rows disorganization and micronuclei frequency increased with increasing dose. The numbers of cells surviving at late times post-irradiation were comparable with those of controls. In addition, the cellular density was similarly unaffected. These observations are consistent with the current theory of the mechanism of radiation cataractogenesis which posits that genomic damage to the epithelial cells surviving the exposure is responsible for opacification.

Crevice-forming mutants of bovine pancreatic trypsin inhibitor: stability changes and new hydrophobic surface

Four mutants of bovine pancreatic trypsin inhibitor (BPTI) with replacements in the rigid core result in the creation of deep crevices on the surface of the protein. Other than crevices at the site of the mutation, few other differences are observed in the crystal structures of wild-type BPTI and the mutants F22A, Y23A, N43G, and F45A. These mutants are highly destabilized relative to wild type (WT). The differences between WT and mutants in the free energy change associated with cooperative folding/unfolding, delta delta G0 (WT-->mut), have been measured by calorimetry, and they are in good agreement with delta delta G0(WT-->mut) values from hydrogen exchange rates. For F22A the change in free energy difference is about 1.7 kcal/mol at 25 degrees C; for the other three mutants it is in the range of 5-7 kcal/mol at 25 degrees C. The experimental delta delta G0(WT-->mut) values of F22A, Y23A, and F45A are reasonably well accounted for as the sum of two terms: the difference in transfer free energy change, and a contribution from exposure to solvent of new surface (Eriksson, A.E., et al., 1992, Science 255, 178-183), if the recently corrected transfer free energies and surface hydrophobicities (De Young, L. & Dill, K., 1990, J. Phys. Chem. 94, 801-809; Sharp, K.A., et al., 1991a, Science 252, 106-109) are used and only nonpolar surface is taken into account. In N43G, three protein-protein hydrogen bonds are replaced by protein-water hydrogen bonds.(ABSTRACT TRUNCATED AT 250 WORDS)

Crevice-forming mutants in the rigid core of bovine pancreatic trypsin inhibitor: crystal structures of F22A, Y23A, N43G, and F45A

Crystal structures of four mutants of bovine pancreatic trypsin inhibitor (F22A, Y23A, N43G, and F45A), engineered to alter their stability properties, have been determined. The mutated residues, which are highly conserved among Kunitz-type inhibitors, are located in the rigid core of the molecule. Replacement of the partially buried bulky residues of the wild-type protein with smaller residues resulted in crevices open to the exterior of the molecule. The overall three-dimensional structure of these mutants is very similar to that of the wild-type protein and only small rearrangements are observed among the atoms lining the crevices.