Connecting single-cell transcriptomes to projectomes in mouse visual cortex

The mammalian brain is composed of diverse neuron types that play different functional roles. Recent single-cell RNA sequencing approaches have led to a whole brain taxonomy of transcriptomically-defined cell types, yet cell type definitions that include multiple cellular properties can offer additional insights into a neuron's role in brain circuits. While the Patch-seq method can investigate how transcriptomic properties relate to the local morphological and electrophysiological properties of cell types, linking transcriptomic identities to long-range projections is a major unresolved challenge. To address this, we collected coordinated Patch-seq and whole brain morphology data sets of excitatory neurons in mouse visual cortex. From the Patch-seq data, we defined 16 integrated morpho-electric-transcriptomic (MET)-types; in parallel, we reconstructed the complete morphologies of 300 neurons. We unified the two data sets with a multi-step classifier, to integrate cell type assignments and interrogate cross-modality relationships. We find that transcriptomic variations within and across MET-types correspond with morphological and electrophysiological phenotypes. In addition, this variation, along with the anatomical location of the cell, can be used to predict the projection targets of individual neurons. We also shed new light on infragranular cell types and circuits, including cell-type-specific, interhemispheric projections. With this approach, we establish a comprehensive, integrated taxonomy of excitatory neuron types in mouse visual cortex and create a system for integrated, high-dimensional cell type classification that can be extended to the whole brain and potentially across species.

[Clinical and genetic characteristics of young patients with myeloproliferative neoplasms]

Objectives: To investigate the clinical and genetic features of young Chinese patients with myeloproliferative neoplasms (MPN). Methods: In this cross-sectional study, anonymous questionnaires were distributed to patients with MPN patients nationwide. The respondents were divided into 3 groups based on their age at diagnosis: young (≤40 years) , middle-aged (41-60 years) , and elderly (>60 years) . We compared the clinical and genetic characteristics of three groups of MPN patients. Results: 1727 assessable questionnaires were collected. There were 453 (26.2%) young respondents with MPNs, including 274 with essential thrombocythemia (ET) , 80 with polycythemia vera (PV) , and 99 with myelofibrosis. Among the young group, 178 (39.3%) were male, and the median age was 31 (18-40) years. In comparison to middle-aged and elderly respondents, young respondents with MPN were more likely to present with a higher proportion of unmarried status (all P<0.001) , a higher education level (all P<0.001) , less comorbidity (ies) , fewer medications (all P<0.001) , and low-risk stratification (all P<0.001) . Younger respondents experienced headache (ET, P<0.001; PV, P=0.007; MF, P=0.001) at diagnosis, had splenomegaly at diagnosis (PV, P<0.001) , and survey (ET, P=0.052; PV, P=0.063) . Younger respondents had fewer thrombotic events at diagnosis (ET, P<0.001; PV, P=0.011) and during the survey (ET, P<0.001; PV, P=0.003) . JAK2 mutations were found in fewer young people (ET, P<0.001; PV, P<0.001; MF, P=0.013) ; however, CALR mutations were found in more young people (ET, P<0.001; MF, P=0.015) . Furthermore, mutations in non-driver genes (ET, P=0.042; PV, P=0.043; MF, P=0.004) and high-molecular risk mutations (ET, P=0.024; PV, P=0.023; MF, P=0.001) were found in fewer young respondents. Conclusion: Compared with middle-aged and elderly patients, young patients with MPN had unique clinical and genetic characteristics.

Regional and cell-type-specific afferent and efferent projections of the mouse claustrum

The claustrum (CLA) is a conspicuous subcortical structure interconnected with cortical and subcortical regions. Its regional anatomy and cell-type-specific connections in the mouse remain not fully determined. Using multimodal reference datasets, we confirmed the delineation of the mouse CLA as a single group of neurons embedded in the agranular insular cortex. We quantitatively investigated brain-wide inputs and outputs of CLA using bulk anterograde and retrograde viral tracing data and single neuron tracing data. We found that the prefrontal module has more cell types projecting to the CLA than other cortical modules, with layer 5 IT neurons predominating. We found nine morphological types of CLA principal neurons that topographically innervate functionally linked cortical targets, preferentially the midline cortical areas, secondary motor area, and entorhinal area. Together, this study provides a detailed wiring diagram of the cell-type-specific connections of the mouse CLA, laying a foundation for studying its functions at the cellular level.

The adenosine A2A receptor antagonist KW6002 distinctly regulates retinal ganglion cell morphology during postnatal development and neonatal inflammation

Adenosine A_2A receptors (A_2ARs) appear early in the retina during postnatal development, but the roles of the A_2ARs in the morphogenesis of distinct types of retinal ganglion cells (RGCs) during postnatal development and neonatal inflammatory response remain undetermined. As the RGCs are rather heterogeneous in morphology and functions in the retina, here we resorted to the Thy1-YFPH transgenic mice and three-dimensional (3D) neuron reconstruction to investigate how A_2ARs regulate the morphogenesis of three morphologically distinct types of RGCs (namely Type I, II, III) during postnatal development and neonatal inflammation. We found that the A_2AR antagonist KW6002 did not change the proportion of the three RGC types during retinal development, but exerted a bidirectional effect on dendritic complexity of Type I and III RGCs and cell type-specifically altered their morphologies with decreased dendrite density of Type I, decreased the dendritic field area of Type II and III, increased dendrite density of Type III RGCs. Moreover, under neonatal inflammation condition, KW6002 specifically increased the proportion of Type I RGCs with enhanced the dendrite surface area and volume and the proportion of Type II RGCs with enlarged the soma area and perimeter. Thus, A_2ARs exert distinct control of RGC morphologies to cell type-specifically fine-tune the RGC dendrites during normal development but to mainly suppress RGC soma and dendrite volume under neonatal inflammation.

Сyclooxygenase-2 Inhibitor Parecoxib Reduces LPS-Induced Activation of BV2 Microglia Cells

We studied the inhibitory effect of cyclooxygenase-2 inhibitor parecoxib on LPS-induced activation of BV2 microglia cells. The optimal dose of parecoxib (80 μmol/liter) was evaluated by the Cell Counting Kit-8. The cells were divided into the following groups: control (intact cells without treatment); LPS (treatment with 1 μg/ml LPS for 6 h), and experimental (pretreatment with 80 μmol/liter parecoxib for 24 h followed by incubation with 1 μg/ml LPS for 6 h). Cell morphology and proliferation and the expression of NLRP3, caspase-1, pro-caspase-1, and IL-1β were assessed. LPS induced significant morphological changes and decreased proliferation of primary BV2 cells in comparison with the control. These changes were prevented by parecoxib pretreatment. LPS significantly increased NLRP3 inflammatory vesicle activation and expression of NLRP3, caspase-1, pro-caspase-1, and IL-1β in comparison with the control group; pretreatment with parecoxib prevented all these changes. Our results suggest that pretreatment with parecoxib inhibited LPS-induced activation of BV2 microglial cells and probably inhibited NLRP3 inflammasome activation.

Unilateral cerebral ischemia induces morphological changes in the layer V projection neurons of the contralateral hemisphere

Decreased blood flow to the brain causes stroke and damage to neuronal networks. Neuronal damage occurs not only in the infarct core but also in areas away from the infarcts. This study was aimed to assess alterations of the cortical projection neurons that were distantly connected with the infarcts. Unilateral cortical ischemia was generated by middle cerebral artery occlusion in the right somatosensory cortex. Pre-labeled thalamocortical neurons disappeared, whereas contralateral callosal projection neurons survived 48 h post-ischemia. The unilateral ischemia increased the total length, segment length and the spine volume of dendrites from layer V callosal neurons in the homotopic cortex of the contralateral hemisphere. The morphological remolding of the contralateral cortical neurons cannot be reproduced by the spinal cord hemisection that cuts axons of corticospinal projection neurons of layer V. The data suggest that the retrograde degeneration of axons may not account for the early morphological changes in the contralateral cortex. We hypothesize that the loss of innervations from the ischemic cortex may bring in adaptive changes to the connected neurons, and adult cortical neurons can adjust their morphology to meet the reduction of synaptic inputs. This study may improve our understanding of the re-organization of cortical circuits following focal cerebral ischemia and help the development of new treatments designed to minimize the disability associated with stroke.

Cellular anatomy of the mouse primary motor cortex

An essential step toward understanding brain function is to establish a structural framework with cellular resolution on which multi-scale datasets spanning molecules, cells, circuits and systems can be integrated and interpreted1. Here, as part of the collaborative Brain Initiative Cell Census Network (BICCN), we derive a comprehensive cell type-based anatomical description of one exemplar brain structure, the mouse primary motor cortex, upper limb area (MOp-ul). Using genetic and viral labelling, barcoded anatomy resolved by sequencing, single-neuron reconstruction, whole-brain imaging and cloud-based neuroinformatics tools, we delineated the MOp-ul in 3D and refined its sublaminar organization. We defined around two dozen projection neuron types in the MOp-ul and derived an input-output wiring diagram, which will facilitate future analyses of motor control circuitry across molecular, cellular and system levels. This work provides a roadmap towards a comprehensive cellular-resolution description of mammalian brain architecture.

Morphological diversity of single neurons in molecularly defined cell types

Dendritic and axonal morphology reflects the input and output of neurons and is a defining feature of neuronal types1,2, yet our knowledge of its diversity remains limited. Here, to systematically examine complete single-neuron morphologies on a brain-wide scale, we established a pipeline encompassing sparse labelling, whole-brain imaging, reconstruction, registration and analysis. We fully reconstructed 1,741 neurons from cortex, claustrum, thalamus, striatum and other brain regions in mice. We identified 11 major projection neuron types with distinct morphological features and corresponding transcriptomic identities. Extensive projectional diversity was found within each of these major types, on the basis of which some types were clustered into more refined subtypes. This diversity follows a set of generalizable principles that govern long-range axonal projections at different levels, including molecular correspondence, divergent or convergent projection, axon termination pattern, regional specificity, topography, and individual cell variability. Although clear concordance with transcriptomic profiles is evident at the level of major projection type, fine-grained morphological diversity often does not readily correlate with transcriptomic subtypes derived from unsupervised clustering, highlighting the need for single-cell cross-modality studies. Overall, our study demonstrates the crucial need for quantitative description of complete single-cell anatomy in cell-type classification, as single-cell morphological diversity reveals a plethora of ways in which different cell types and their individual members may contribute to the configuration and function of their respective circuits.

A multimodal cell census and atlas of the mammalian primary motor cortex

Here we report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties and cellular resolution input-output mapping, integrated through cross-modal computational analysis. Our results advance the collective knowledge and understanding of brain cell-type organization1-5. First, our study reveals a unified molecular genetic landscape of cortical cell types that integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a consensus taxonomy of transcriptomic types and their hierarchical organization that is conserved from mouse to marmoset and human. Third, in situ single-cell transcriptomics provides a spatially resolved cell-type atlas of the motor cortex. Fourth, cross-modal analysis provides compelling evidence for the transcriptomic, epigenomic and gene regulatory basis of neuronal phenotypes such as their physiological and anatomical properties, demonstrating the biological validity and genomic underpinning of neuron types. We further present an extensive genetic toolset for targeting glutamatergic neuron types towards linking their molecular and developmental identity to their circuit function. Together, our results establish a unifying and mechanistic framework of neuronal cell-type organization that integrates multi-layered molecular genetic and spatial information with multi-faceted phenotypic properties.

A simplified morphological classification scheme for pyramidal cells in six layers of primary somatosensory cortex of juvenile rats

The majority of neurons in the neocortex are excitatory pyramidal cells (PCs). Many systematic classification schemes have been proposed based the neuronal morphology, the chemical composition, and the synaptic connectivity, etc. Recently, a cortical column of primary somatosensory cortex (SSC) has been reconstruction and functionally simulated (Markram et al., 2015). Putting forward from this study, here we proposed a simplified classification scheme for PCs in all layers of the SSC by mainly identifying apical dendritic morphology based on a large data set of 3D neuron reconstructions. We used this scheme to classify three types in layer 2, two in layer 3, three in layer 4, four in layer 5, and six types in layer 6. These PC types were visually distinguished and confirmed by quantitative differences in their morphometric properties. The classes yielded using this scheme largely corresponded with PC classes that were defined previously based on other neuronal and synaptic properties such as long-range projects and synaptic innervations, further validating its applicability. Therefore, the morphology information of apical dendrites is sufficient for a simple scheme to classify a spectrum of anatomical types of PCs in the SSC.

Curcumin Inhibits Proliferation and Epithelial-Mesenchymal Transition of Retinal Pigment Epithelial Cells Via Multiple Pathways

BACKGROUND

Proliferative vitreoretinopathy (PVR) is a disease caused by dedifferentiation, translocation and proliferation of several types of local cells. These cells form fibrocellular membranes resulting in detachment of retinal and vision loss. PVR occurs in 8%-10% of patients undergoing primary retinal detachment (RD) surgery and becomes a major obstacle for successful RD repair. Retinal pigment epithelial (RPE) cells are among the major cells which consist of fibrocellular membranes. Reproliferation and Epithelial-mesenchymal transition (EMT) are the primary pathological alteration of RPE cells in PVR.

METHODS

RPE cells were treated with curcumin at different concentrations for 24, 48 and 72 hours. The viable cells were detected by MTT assay. The apoptosis of RPE was stained by Multicaspase/7-AAD and detected using flow cytometry. Cell cycle analysis was quantified by PI staining. The mRNA levels were detected by real-time PCR. The protein levels were detected by western blot.

RESULTS

We found a compound curcumin significantly inhibited proliferation and EMT of RPE cells in vitro. Further study showed curcumin induced cell cycle arrest by activating G2 checkpoint through p53 pathway. Meanwhile, we found that curcumin suppressed the AKT, MAPK and TGF-β pathways in RPE cells which may also affect proliferation and EMT. Our research identified curcumin a potential novel agent for the PVR prevention and treatment. Curcumin induces cell cycle arrest by activating G2 checkpoint.

CONCLUSION

Our results in this study also provide the insights to broaden the application of curcumin in research and probably clinics.

Neonatal inflammation induces reorganization in dendritic morphology of retinal ganglion cells but not their retinogeniculate projection in mice

Perinatal inflammatory insult in preterm babies is associated with vision impairment, but the underlying cellular mechanism is still unknown. In this study, we set out to explore whether systemic inflammatory stress affects the development of retinal ganglion cells (RGCs). Neonatal inflammation was induced by single and systemic injection of lipopolysaccharide (LPS, 1 mg/kg) at postnatal day 4 (P4). Morphological changes of RGCs were investigated by using 3D neuron reconstruction technique in Thy-1 YFPH transgenic mice at P21, of which a fraction of RGCs selectively expresses the yellow fluorescent protein (YFP). Three types (Type I, II, III) of RGCs were distinguished and classified according to the characteristic features in their dendritic field area and dendrite density. Neonatal exposure to LPS did not alter the composition of the three RGC types but induced a reorganization of dendritic architecture in the RGC Type I and II (but not Type III). The average diameter, surface area and volume of dendrites in both RGC Type I and II were increased after systemic inflammation compared with those in the control group. However, soma sizes of all three RGC types were not affected by neonatal inflammation. Meanwhile, using anterograde labeling of the retinal cells, we found that neonatal exposure to LPS also did not affect the pattern of RGC projections in the dorsal lateral geniculate nucleus of the thalamus (dLGN). These results indicate that RGC dendrite reorganization induced by neonatal inflammation may contribute to the retinal cell dysfunctions associated with systemic inflammation in premature babies.

Potential deficit from decreased cerebellar granule cell migration in serine racemase-deficient mice is reversed by increased expression of GluN2B and elevated levels of NMDAR agonists

Inward migration of cerebellar granule cells (CGCs) after birth is critical for lamination in the cerebellar cortex. N-methyl-d-aspartate (NMDA) subtype of glutamate receptor (NMDAR) tethering CGCs into Bergmann glial fibers mediates the inward movement during the glial-dependent migratory phase. Activation of NMDAR depends on simultaneous binding of the GluN2 subunit by glutamate, and of the GluN1 subunit by d-serine or glycine; d-serine is believed to be an endogenous ligand of NMDAR. We hypothesized that lamination of the cerebellar cortex may be compromised in Srr (the gene for serine racemase (SR)) mutated mice (Srr_null) because of significantly low levels of d-serine per se. Indeed, the external germinal cell layer (EGL) in Srr_null was thicker than in sibling wild-type (WT) mice on postnatal day7 (P7), which accords with decreased CGC migration in Srr_null mice. However, the cerebellar laminar structure in Srr_null mice was normal on P12 and later. Feeding d-serine to pregnant mice abrogated the increased EGL thickness in Srr_null mice on P7. To determine the underlying mechanism of abnormal laminar structure during cerebellar development in Srr_null mice, we examined NMDAR subunits and their ligands. We found increased GluN2B on P10 and increased glycine during P7-12 in the cerebellar homogenates from Srr_null mice compared with the corresponding values from sibling WT mice. In summary, the study revealed how the potential defect in early cerebellar development caused by Srr mutation is circumvented by a compensatory mechanism. This knowledge advances understanding of the adaptation of cerebellar development under the condition of Srr mutation.

Abstract P6-01-16: The phosphorylation-specific association of STMN1 with GRP78 promotes breast cancer metastasis

This abstract was not presented at the symposium.

Diagnostic value of recombinant Tp0821 protein in serodiagnosis for syphilis

Syphilis is a multistage sexually transmitted disease that remains a serious public health concern worldwide. The coexistence of Treponema pallidum with other closely related members of spirochaeta, such as Leptospira spp. and Borrelia burgdorferi, has complicated the serodiagnosis due to cross-reactive antigens. In this study, recombinant Tp0821 protein was expressed in Escherichia coli and purified by metal affinity chromatography. Then enzyme-linked immunosorbent assays (ELISAs) based on Tp0821 for the detection of specific antibodies were established. The relative positive rates of the IgM ELISA and the IgG ELISA were found to be 91·0 and 98·3%, respectively, when screening 578 syphilis specimens. The specificities were 94·3 and 100%, respectively, when cross-checking with serum samples obtained from 30 patients with Lyme disease, five patients with leptospirosis, and 52 uninfected controls. In addition, relative positive rates and specificities of Tp0821 for human sera were all 100% in Western blotting. When compared to the syphilis diagnostic tests commonly used in clinical settings, we found that the results of Tp0821-based ELISAs correlated well with the results of the treponemal tests, specifically the T. pallidum particle agglutination (TP-PA) test and the chemiluminescent immunoassay (CIA). Thus, these findings identify Tp0821 as a novel serodiagnostic candidate for syphilis.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study, we expressed and purified the Treponema pallidum protein Tp0821 and developed Tp0821-based enzyme-linked immunosorbent assays (ELISAs) for the detection of specific antibodies. The serodiagnostic performance of the recombinant protein was then evaluated. When compared to the results of syphilis diagnostic tests commonly used in clinical settings, we found that the reactivities of syphilitic sera with the recombinant antigen correlated well with the results of the treponemal tests, specifically the T. pallidum particle agglutination (TP-PA) test and the chemiluminescent immunoassay (CIA). Thus, the recombinant protein shows promise as a new diagnostic antigen in the ELISAs.

Identification of Campylobacter jejuni and determination of point mutations associated with macrolide resistance using a multiplex TaqMan MGB real-time PCR

AIMS

The aim of the study was to develop a multiplex real-time PCR method to identify Campylobacter jejuni containing mutations commonly associated with macrolide resistance.

METHODS AND RESULTS

A multiplex fluorescence real-time PCR assay was developed based on TaqMan minor groove binder (MGB) probes. The VS1-MGB probe was designed based on the VS1 gene and was used to identify Camp. jejuni. The 23S rDNA-MGB probe was designed to distinguish macrolide resistance mutations in 23S rDNA, while 57D-MGB and 74D-MGB were designed to detect resistance mutations in ribosomal protein L4. The specificity and accuracy of our method were identical to the conventional biochemical tests, mapA PCR, minimum inhibitory concentration (MIC) determination and DNA sequencing. The linear detection limit of the method was 0·03 ng genomic DNA and three colony formation unit (CFU) per reaction. In 6 of 18 cases, the nature of Erythromycin resistance could be correctly determined from natural isolates; absence of the tested mutations was demonstrated in the remaining four resistant isolates.

CONCLUSIONS

A multiplex TaqMan MGB real-time PCR assay with high specificity and accuracy was developed to simultaneously identify Camp. jejuni and detect the gene mutations associated with macrolide resistance.

SIGNIFICANCE AND IMPACT OF THE STUDY

This multiplex method can potentially simplify the identification of Camp. jejuni and determine macrolide resistance due to mutations in 23S rDNA or ribosomal protein L4. This method has a potential for application in different research areas and molecular surveillance.

Effect of intermittent normobaric hyperoxia for treatment of neuropathic pain in Chinese patients with spinal cord injury

STUDY DESIGN

Prospective, randomized and controlled study.

OBJECTIVES

The aim of the study was to investigate the effect of intermittent normobaric hyperoxia (InHO) for treatment of neuropathic pain in patients with spinal cord injury (SCI).

SETTING

The First Affiliated Hospital of Nanhua University, Hengyang, Hunan Province, China.

METHODS

Patients with SCI from Hunan Province were recruited from the First Affiliated Hospital of Nanhua University. History, duration, localization and characteristics of pain were recorded. Visual analog scale (VAS), the Patient Global Impression of Change (PGIC) and Short Form-36 walk-wheel (SF-36ww) was used to investigate the effect of InHO. Patients were randomly assigned to study and control groups. In study group, patients were exposed to pure oxygen via non-rebreathing reservoir mask, which increased the provided oxygen at a rate of 7 l min^-1 for 1 or 4 h daily in 2 weeks. While in control group, patients breathed air via non-rebreathing reservoir mask at the same rate.

RESULTS

A total of 62 SCI patients with neuropathic pain were included in the study. The mean age of the patients was 36.85±10.71 years. Out of 62 patients, 21 were tetraplegic and 41 were paraplegic. Overall, 14 patients had complete SCI while 48 patients had incomplete injuries. Three groups were similar with respect to age, gender, duration, smoker or not, level and severity of injury. In the 4 h per day InHO groups, a statistically significant reduction of the VAS values was observed (P<0.05). Significant difference was also found in SF-36ww pain scores and PGIC (P<0.05). However, such an effect was not evident in the control group.

CONCLUSION

This study revealed that in treatment of neuropathic pain of SCI patients, InHO may be effective.

PERSPECTIVE

This article presents InHO may effectively complement pharmacological treatment in patients with SCI and neuropathic pain.

Filtration and clogging of permeable pavement loaded by urban drainage

Permeable pavement, as a sustainable infrastructure material can promote hydrologic restoration, particulate matter (PM) and solute control. However, filtration and commensurate clogging are two aspects of continued interest and discussion. This study quantifies filtration and clogging of cementitious permeable pavement (CPP) for loadings from 50 to 200 mg/L of hetero-disperse sandy-silt PM. The CPP mix design provides a hetero-disperse pore size distribution (PSD)(pore), effective porosity (φ(e)) of 24% and median pore size of 658 μm with a standard deviation of 457 μm. The PM mass separation across the entire particle size distribution (PSD)(PM) exceeds 80%; with complete separation for PM greater than 300 μm and 50% separation for suspended PM. Turbidity is reduced (42-95%), and effluent is below 10 NTU in the first quartile of a loading period. Permeable pavement illustrates reductions in initial (clean-bed) hydraulic conductivity (k(0)) with loading time. For all PM loadings, k(0) (3.1 × 10(-1) mm/s) was reduced to 10(-4) mm/s for runoff loading durations from 100 to 250 h, respectively. Temporal hydraulic conductivity (k) follows exponential profiles. Maintenance by vacuuming and sonication illustrate that 96-99% of k(0) is recovered. Permeable pavement constitutive properties integrated with measured PM loads and a year of continuous rainfall-runoff simulation illustrate k reduction with historical loadings. Study results measure and model filtration and hydraulic conductivity phenomena as well as maintenance requirements of permeable pavement directly loaded by urban drainage.

Monosodium luminol upregulates the expression of Bcl-2 and VEGF in retrovirus-infected mice through downregulation of corresponding miRNAs

The retrovirus ts1 is a mutant of Moloney murine leukemia virus (MoMuLV) that causes neurodegeneration (ND) in susceptible mice. Our previous studies showed that the antioxidant drug monosodium luminol (GVT) prevented the development of ND in ts1-infected mice. In this study, we analyzed effect of GVT on the expression of B-cell lymphoma-2 protein (Bcl-2) and vascular endothelial growth factor (VEGF) in central nervous system (CNS) tissues of these animals. Our data showed that GVT treatment of ts1-infected mice significantly increased their expression of Bcl-2 and VEGF in brainstem compared with ts1-infected untreated mice. We also studied the expression of specific microRNAs (miRNAs) such as miRNA-15 and -16 (targeting Bcl-2), and miRNA-20 (targeting VEGF). We found that the expression of miRNAs inversely correlated with the upregulation of their target proteins in ts1-infected untreated as well as in GVT-treated-ts1-infected mice. The data showed that GVT treatment prevented ts1-induced ND at least in part by upregulating Bcl-2 and VEGF expression, what likely occurred as a consequence of downregulation of their corresponding miRNAs.

Gene Expression of Manganese-Containing Superoxide Dismutase as a Biomarker of Manganese Bioavailability for Manganese Sources in Broilers

The goal of this study was to determine whether Mn-containing superoxide dismutase (MnSOD) gene expression in heart tissue would reflect differences among bioavailabilities of Mn sources earlier than other indices. Broilers were divided into 5 groups and fed a Mn-unsupplemented basal diet (control) or the basal diet supplemented with 120 mg of Mn/kg as Mn sulfate or Mn methionine E (Mn Met E), Mn amino acid B (Mn AA B), or Mn amino acid C (Mn AA C) with weak, moderate, or strong chelation strength, respectively. Heart MnSOD mRNA levels were analyzed using quantitative reverse transcription-PCR at 7, 14, or 21 d. The results showed that heart MnSOD mRNA level increased as dietary Mn level increased at any age. At 7 d, chicks fed the diet supplemented with Mn AA B had higher MnSOD mRNA levels than those fed the diet supplemented with Mn sulfate and Mn Met E, and the same tendency was observed at 14 or 21 d. The results suggest that MnSOD gene expression, which is regulated by dietary Mn at transcriptional level, could reflect differences among bio-availabilities of organic Mn sources as early as 7 d. Therefore, the estimation of relative bioavailabilities of Mn sources based on heart MnSOD mRNA level could require a shorter experimental period and a smaller number of animals, and thus less cost.

Neuroprotective role of Z-ligustilide against forebrain ischemic injury in ICR mice

Radix Angelica sinensis, known as Danggui in Chinese, has been used to treat cardiovascular and cerebrovascular diseases in Traditional Chinese Medicine for a long time. Modern phytochemical studies showed that Z-ligustilide (LIG) is the main lipophilic component of Danggui. In this study, we examined whether LIG could protect ischemia/reperfusion-induced brain injury by minimizing oxidative stress and anti-apoptosis. Transient forebrain cerebral ischemia (FCI) was induced by the bilateral common carotid arteries occlusion for 30 min. LIG was intraperitoneally injected to ICR mice at the beginning of reperfusion. As determined via 2,3,5-triphenyl tetrazolium chloride (TTC) staining at 24 h following ischemia, the infarction volume in the FCI mice treated without LIG (22.1 +/- 2.6%) was significantly higher than that in the FCI mice treated with 5 mg/kg (11.8 +/- 5.2%) and 20 mg/kg (2.60 +/- 1.5%) LIG (P < 0.05 or P < 0.01). LIG treatment significantly decreased the level of malondialdehyde (MDA) and increased the activities of the antioxidant enzyme glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) in the ischemic brain tissues (P < 0.05 or P < 0.01 vs. FCI group). In addition, LIG provided a great increase in Bcl-2 expression as well as a significant decrease in Bax and caspase-3 immunoreactivities in the ischemic cortex. The findings demonstrated that LIG could significantly protect the brain from damage induced by transient forebrain cerebral ischemia. The antioxidant and anti-apoptotic properties of LIG may contribute to the neuroprotective potential of LIG in cerebral ischemic damage.

Use of chemical characteristics to predict the relative bioavailability of supplemental organic manganese sources for broilers1

Twelve organic Mn sources and MnSO4 were evaluated by polarographic analysis and via solubility in buffers (pH 5 and 2) and deionized water. Fractions from solubility tests were evaluated by gel filtration chromatography for structural integrity. Organic Mn sources included five Mn methionine complexes (Mn Met A to Mn Met E), two Mn proteinates (Mn Pro A and Mn Pro B), and five Mn amino acids (Mn AA A to Mn AA E). Sources varied considerably in chemical characteristics. Chelation strength (Qf) ranged from weak (1.9 Qf-values) to strong complexes (115.4 Qf-values). No complexed Mn was found in filtrates at pH 2.0 or 5.0. A 42-d bioassay was used to estimate relative bioavailability of Mn sources for chicks fed diets supplemented with 60, 120, or 180 mg Mn/kg. Bone Mn, heart Mn, heart manganese-superoxide dismutase activity (MnSOD), and heart MnSOD mRNA increased (P < 0.001) as dietary Mn increased. Only heart MnSOD mRNA tended (P < 0.10) to differ among dietary Mn sources. For bioassays of Mn, the MnSOD mRNA level in heart was more sensitive than the MnSOD activity in heart or other indices. Relative to MnSO4 (assigned 100%), slope ratios of MnSOD mRNA levels in heart gave bioavailabilities of 99, 132, and 113% for Mn Met E, Mn AA B, and Mn AA C sources with weak, moderate, and strong chelation strength, respectively. The bioavailability of Mn was more closely related to chelation strength as measured by polarography than to chemical traits assessed by solubility or structural integrity.

[Effects of Rg1 on calcium channel of guinea pig ventricular myocytes]

OBJECTIVE

To evaluate the effect of Rg1 (purified saponin of Panax notoginseng) on L-Ca2+ channel of guinea pig ventricular myocytes.

METHOD

The whole-cell patch clamp recording technique.

RESULT

When the holding potential was kept at -40 mV, and the cell was depolarized to +40 mV for 150 ms at a frequency of 0.5 Hz.Rg1 10 mumol.L-1 and 30 mumol.L-1 could not reduce Bay K 8644 and nifedipine-sensitive L-type Ca2+ inward current (P > 0.05, n = 5).

CONCLUSION

Rg1 should not be a Ca2+ channel antagonist.

[Effect of enoxacin on pharmacokinetics of theophylline in rats]

In order to obtain an experimental evidence for Enoxacin(ENX) to be correctly used in clinical treatment, we studied the effect of ENX on the pharmacokinetic parameters of theophylline(TP). A single oral dose of TP 20 mg/kg was given to rats and ENX(300 mg/kg, 450 mg/kg) was co-administered orally three times to those rats. The plasma concentrations of TP were determined by HPLC after TP was administered 1, 2, 3, 5, 7, 12 and 24 hrs. The results showed that TP was eliminated by one compartment model. TP plasma concentrations and AUC were significantly increased. T1/2 beta of TP was prolonged. The total clearance of TP was decreased when compared with the control. This interaction was dose-dependent. It was concluded that the interaction between ENX and TP existed. Concomitant use of ENX with TP should be avoided.

[Determination of normal temperature properties of refractory die material compatible with slip casting core of sintered titanium powder]

OBJECTIVE

The refractory die is the precondition for developing slip casting core of sintered powder. This study is to determine the normal temperature properties of the refractory die material compatible with slip casting core.

METHODS

to mix the die material at five different ratios (8/1, 7.5/1, 7/1, 6.5/1, and 6/1) and measure their solidification time with self-manufactured Vicker's needle; to prepare five cylindrical specimens (phi 10 x 15 mm) in different drying time for determining their compressive strength, and then to let another five specimens fire at 1000 degrees C four times for measuring the residual compressive strength at room temperature.

RESULTS

The setting time was 16.25 minutes (7.5/1), and the lower the powder-liquid ratio, the longer the setting time. The normal compressive strength was 25.32 MPa (drying 24 hours), while the longer the drying time, the higher the compressive strength achieved (P < 0.01). The residual compressive strength was 24 MPa.

CONCLUSION

The normal temperature properties of the refractory die material meet the demand of slip casting core of sintered powder.

[Effects of occupational exposure to formamidines on cardiovascular functions]

OBJECTIVE

To understand the possible effects of occupational exposure to formamidines on human cardiovascular function, this study was carried out.

METHODS

Sixteen farmers spraying chlordimeform, 14 packers packaging chlordimeform and 23 packers packaging mono-formamidine were followed-up pre- and post-exposure. Their urinary excretion of formamidine or its metabolite, as well as air concentrations of formamidine at their work places and their skin contamination with it were measured to estimate the exposure level. Furthermore, 24-hour urinary level of vanillinmandelic acid (VMA) was analyzed among mono-formamidine packers.

RESULTS

Their whole body skin contaminated with 3.240 and 2.142 g/cm(2) of chlordimeform in the sprayers and packers, respectively. Their hand skin contaminated with mono-formamidine at 6.59 g/cm(2) in the packers. It indicated that the major route of exposure to formamidine was skin contamination. Urinary levels of formamidines or their metabolites increased significantly after exposure, reaching 6.194 and 3.378 micromol/L for the sprayers and packers exposed to chlordimeform, respectively, and 2.760 - 3.427 micromol/L for mono-formamidine in the packers. Their heart rates slowed down, P-R and Q-T intervals prolonged and blood pressure reduced after exposure, as compared with those before exposure. Consistency of the results in several studies demonstrated that formamidines could induce changes in the indices for cardiovascular functions under the relatively low exposure levels at present. Decrease of urinary VMA from 0.068 micromol/L pre-exposure to 0.040 - 0.055 micromol/L post-exposure suggested that catecholamine could play a role in these effects.

CONCLUSION

Formamidines has certain effects on human cardiovascular function. It is suggested that attention be paid to the changes in cardiovascular functions of those exposed in their health surveillance.

[Determination of high temperature compressive strength and refractory degree of die material compatible with slip casting core of sintered titanium powder]

OBJECTIVE

The refractory die is the precondition for developing slip casting core of sintered powder. This study is to determine the high temperature properties of the refractory die material compatible with slip casting core.

METHODS

To prepare three cylindrical specimens (phi 10 x 15 mm) and determine their compressive strength at 1000 degrees C: to make four specimens in flat-topped cone for determining the practical refractory degree by decreasing the pressing temperatures in a sequence of 1420, 1400, 1350 and 1100 degrees C.

RESULTS

The compressive strength of this material was 17.8 MPa at 1000 degrees C. Its practical refractory degree was higher than 1100 degrees C.

CONCLUSION

The high temperature properties of the refractory die material that we developed meet the demand of slip casting core of sintered powder.

[Determination of major expansion properties of refractory die material compatible with slip casting core of sintered titanium powder]

OBJECTIVE

To determinate major expansion properties of refractory die material.

METHODS

The setting expansion ratio of refractory die material for slip casting core of sintered titanium powder at room temperature was performed, as well as thermal expansion ratio from room temperature to 800 degrees C.

RESULTS

The maximum setting expansion ratio in 2 hours reached 0.3407%; The final setting expansion ratio in 24 hours was 0.3117%; The mean thermal expansion coefficient was mainly in range of 8 x 10(-6)-11 x 10(-6)/degree C; The expansion property seemed very stable after sintering repeatedly and the small shrinkage after sintering could be compensated with the die spacer and setting expansion.

CONCLUSION

The expansion properties of the refractory die material that we synthesized can fulfil the application requirements of slip casting core of sintered titanium powder.

Isolation and characterisation of neurotoxigenic Clostridium butyricum from soil in China

Soil specimens collected from a site around the home of patients with food-borne type E. botulism probably caused by neurotoxigenic Clostridium butyricum in Guanyun, Jiangsu province, China, were examined for the presence of neurotoxigenic C. butyricum. Five lakeside sites of Weishan lake, in an area near to the sites where the type E. botulism outbreaks caused by neurotoxigenic C. butyricum occurred were also surveyed. Type E toxin-producing C. butyricum was isolated from soil from four sites including the site in Guanyun. Polymerase chain reaction assay demonstrated the presence of the type E toxin gene in all the toxigenic isolates. The biochemical properties of the isolates from the Guanyun soil and the lakeside soil were identical except for inulin fermentation and starch hydrolysis properties. These results indicate that neurotoxigenic C. butyricum has its principal habitat in soil.

Preparation and characterization of new electrocardiogram electrodes

A new generation of electrocardiogram (ECG) electrodes have been fabricated and superficially modified by a special controlled precorrosion process. The electrodes have been characterized by scanning electron microscopy (SEM), resistance-capacitance measurements (RCM) and simulated defibrillation recovery (SDR). The resulting surface of the Sn alloys was rough, and, consequently, a large active surface area was available. As a result, a higher electrocardiogram electrode performance, including low alternating current (a.c.) impedance, excellent time stability and improved SDR, was achieved. Such new design can surely find important future applications in clinical diagnosis.

[The influence of porcelain thickness and non-uniformity on porcelain cracks in implant-supported metal-porcelain fixed bridge]

This experiment studied the influence of porcelain thickness and non-uniformity on porcelain crack in implant-supported metal-porcelain fixed bridge. The result indicated that porcelain crack began to appear when the body porcelain powder was 3-5 mm in thickness; more cracks took place when the powder thickness increased by 1 mm to 2 mm on the axial surface in the axial direction; cracks became serious when the thickness suddenly changed to zero; and connectors were liable to cracks. Therefore, in designing and fabrication, one should avoid and sudden change in the shapes of the connector and the porcelain on it, any sudden change in the thickness of porcelain and a thickness of porcelain powder not less than 3.5 mm. Other-wise, it is neccessary to use internal crown between metal base and abutment to meet the demands.

Characterization of a neurotoxigenic Clostridium butyricum strain isolated from the food implicated in an outbreak of food-borne type E botulism

Neurotoxigenic Clostridium butyricum was isolated from the food implicated in an outbreak of clinically diagnosed type E botulism in China. PCR assay showed that the isolate (LCL 155) contained the type E botulinum toxin gene. This appears to be the first report of neurotoxigenic C. butyricum causing food-borne botulism.

[Effects of the fruit of Rubus chingii Hu on hypothalamus-pituitary-sex gland axis in rats]

The aqueous extract of the fruit of Rubus chingii (RCH) can decrease the contents of LH, FSH and E2, and increase the content of LHRH secreted by thymus gland as well as the level of testosterone in blood.

[Study on combined acupunctural and general anesthesia in pneumonectomy]

Combined acupunctural and general anesthesia in pneumonectomy were studied. The result showed that general anesthesia complemented with electro-acupuncture at He Gu (LI 4) and San Yang Luo(SJ 8) reduced amount of Fentanyl 38-85 micrograms/h compared with general anesthesia alone. There were no statistical difference in blood pressure and heart rate during the operation in every group, all of the SPO2 were in normal range. It was considered that acupuncture in combination with general anesthesia could reduce dosage of anesthetics and the inhibition of physiological function. It is a practical and acceptable anesthetic method by the surgeon and patient.