Comparative genomics of widespread and narrow-range white-bellied rats in the Niviventer niviventer species complex sheds light on invasive rodent success

Widespread species that inhabit diverse environments possess large population sizes and exhibit a high capacity for environmental adaptation, thus enabling range expansion. In contrast, narrow-range species are confined to restricted geographical areas and are ecologically adapted to narrow environmental conditions, thus limiting their ability to expand into novel environments. However, the genomic mechanisms underlying the differentiation between closely related species with varying distribution ranges remain poorly understood. The Niviventer niviventer species complex (NNSC), consisting of highly abundant wild rats in Southeast Asia and China, offers an excellent opportunity to investigate these questions due to the presence of both widespread and narrow-range species that are phylogenetically closely related. In the present study, we combined ecological niche modeling with phylogenetic analysis, which suggested that sister species cannot be both widespread and dominant within the same geographical region. Moreover, by assessing heterozygosity, linkage disequilibrium decay, and Tajima's D analysis, we found that widespread species exhibited higher genetic diversity than narrow-range species. In addition, by exploring the "genomic islands of speciation", we identified 13 genes in highly divergent regions that were shared by the two widespread species, distinguishing them from their narrow-range counterparts. Functional annotation analysis indicated that these genes are involved in nervous system development and regulation. The adaptive evolution of these genes likely played an important role in the speciation of these widespread species.

Phylogeography and Genetic Structure of the Bush Cricket Decma fissa (Orthoptera, Tettigoniidae) in Southern China

Decma fissa is the most widely distributed species of the genus Decma occuring in southern China. This study presents the first phylogeographic work of D. fissa based on COI, Cytb and ITS sequence. We examined genetic diversity with ITS and mitochondrial sequence respectively, and phylogenetic work was based on the mitochondrial data. A high-level genetic diversity was revealed based on mitochondrial data but a low-level diversity was shown with ITS sequence. For the mitochondrial data, divergence time analysis displayed five lineages. Based on the Mantel test, geographic and genetic distances among D. fissa populations revealed a significant positive correlation. Bayesian skyline plot (BSP) analyses implied that none of three major lineages of D. fissa was seemingly affected by the last glacial maximum (LGM, 0.015-0.025 Mya). Ecological niche modeling was used to predict the distribution of D. fissa in four periods (LGM, Mid-Holocene, current and 2070) in China. Analysis of the ancestral area reconstruction indicated that D. fissa occurred in the South China area.

Crop rotations increased soil ecosystem multifunctionality by improving keystone taxa and soil properties in potatoes

Continuous cropping of the same crop leads to soil degradation and a decline in crop production, and these impacts could be mitigated through rotation cropping. Although crop rotation enhances soil fertility, microbial community diversity, and potato yield, its effects on the soil ecosystem multifunctionality (EMF) remain unclear. In the present research, we comparatively examined the effects of potato continuous cropping (PP) and rotation cropping [potato-oat rotation (PO) and potato-forage maize rotation (PFM)] on the soil EMF as well as the roles of keystone taxa, microbes abundance, and chemical properties in EMF improvement. It was demonstrated that soil EMF is increased in rotation cropping (PO and PFM) than PP. Soil pH was higher in rotation cropping (PO and PFM) than in PP, while total phosphorus (TP) and available phosphorus (AP) were significantly decreased than that in PP. Rotation cropping (PO and PFM) markedly changed the bacterial and fungal community compositions, and improved the potential plant-beneficial fungi, e.g., Schizothecium and Chaetomium, while reducing the abundances of the potentially phytopathogenic fungi, e.g., Alternaria, Fusarium, Verticillium dahiae, Gibberella, Plectosphaerella, Colletotrichum, Phoma, and Lectera in comparison with PP. Also, co-occurrence patterns for bacteria and fungi were impacted by crop rotation, and keystone taxa, e.g., Nitrospira.1, Lysinibacillus, Microlunatus.1, Sphingomonas.3, Bryobacter.1, Micromonospora, and Schizothecium, were enriched in PO and PFM than PP. The structural equation model (SEM) further demonstrated that cropping systems increased soil ecosystem multifunctionality through regulating SOM and keystone taxa (Schizothecium1), and keystone taxa were mediated by soil pH. This study suggested that rotation cropping might contribute to the improvement of soil ecosystem multifunctionality as well as the development of disease-suppressive soils in comparison with potato continuous cropping.

Paraquat mediates BV-2 microglia activation by raising intracellular ROS and inhibiting Akt1 phosphorylation

Microglia is the innate immune cell in central nervous system (CNS) and plays an important role in neuroinflammation. Microglia mediated neuroinflammation is the key factor affecting the development of neurodegenerative diseases. Although there was evidence that paraquat (PQ) could induce inflammatory response, its mechanism was not clear. The present study investigated the mechanisms of PQ-induced inflammatory responses in BV-2 microglia cells, and tried to reveal the role of ROS/Akt1 pathway. The results showed that the cell activation markers (iNOS and CD206) of BV-2 cells were increased after PQ treatment, suggesting that BV-2 microglia were activated. PQ induced the reactive oxygen species (ROS) and inhibited the AKT1 phosphorylation in BV-2 cells. Besides, the M1 markers expression (IL-6, TNF-α and IL-1β) were significantly increased after PQ treatment, which suggested that PQ induced the increase of M1 phenotype of BV-2 microglia. Pre-treated with NAC (ROS scavenger), the M1 phenotype was decreased while the p-Akt1 was restored compared to PQ stimulation. Furthermore, we built an Akt1(S473E)-overexpression BV-2 cell line. The Akt1 (S473E) partially attenuated the PQ induced increase in M1 phenotype, while ROS did not significantly change. These results indicated that PQ induced BV-2 microglia activation by increased ROS mediated Akt1 activation inhibition, leading to neuroinflammation.

A flexible electrode array for determining regions of motor function activated by epidural spinal cord stimulation in rats with spinal cord injury

Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury. The key challenges within the reconstruction of motor function for paralyzed limbs are the precise control of sites and parameters of stimulation. To activate lower-limb muscles precisely by epidural spinal cord stimulation, we proposed a high-density, flexible electrode array. We determined the regions of motor function that were activated upon epidural stimulation of the spinal cord in a rat model with complete spinal cord, which was established by a transection method. For evaluating the effect of stimulation, the evoked potentials were recorded from bilateral lower-limb muscles, including the vastus lateralis, semitendinosus, tibialis anterior, and medial gastrocnemius. To determine the appropriate stimulation sites and parameters of the lower muscles, the stimulation characteristics were studied within the regions in which motor function was activated upon spinal cord stimulation. In the vastus lateralis and medial gastrocnemius, these regions were symmetrically located at the lateral site of L1 and the medial site of L2 vertebrae segment, respectively. The tibialis anterior and semitendinosus only responded to stimulation simultaneously with other muscles. The minimum and maximum stimulation threshold currents of the vastus lateralis were higher than those of the medial gastrocnemius. Our results demonstrate the ability to identify specific stimulation sites of lower muscles using a high-density and flexible array. They also provide a reference for selecting the appropriate conditions for implantable stimulation for animal models of spinal cord injury. This study was approved by the Animal Research Committee of Southeast University, China (approval No. 20190720001) on July 20, 2019.

Genetic diversity and structure of Oncomelania hupensis hupensis in two eco-epidemiological settings as revealed by the mitochondrial COX1 gene sequences

BACKGROUND

Oncomelania hupensis hupensis is the only intermediate host of Schistosoma japonicum, the causative agent of schistosomiasis in China and is therefore of significant medical and veterinary health importance. Although tremendous progress has been achieved, there remains an understudied area of approximately 2.06 billion m² of potential snail habitats. This area could be further increased by annual flooding. Therefore, an understanding of population genetics of snails in these areas may be useful for future monitoring and control activities.

METHODS AND RESULTS

We sampled snails from Hexian (HX), Zongyang (ZY) and Shitai (ST) in Anhui (schistosomiasis transmission control), and from Hengtang (HT), Taicang (TC), Dongsan (DS) and Xisan (XS) in Jiangsu (schistosomiasis transmission interrupted), downstream of Anhui. ST, DS and XS are classified as hilly and mountainous areas, and HX, ZY, TC and HT as lake and marshland areas. The mitochondrial cytochrome c oxidase subunit I gene were sequenced. Out of 115 snails analyzed, 29 haplotypes were identified. We observed 56 (8.72%) polymorphic sites consisting of 51 transitions, four transversions and one multiple mutational change. The overall haplotype and nucleotide diversity were 0.899 and 0.01569, respectively. Snail populations in Anhui had higher genetic diversity than in Jiangsu. 73.32% of total variation was distributed among sites and 26.68% within sites. Snails were significantly separated according to eco-epidemiological settings in both network and phylogenetic analyses.

CONCLUSION

Our results could provide important guidance towards assessing coevolutionary interactions of snails with S. japonicum, as well as for future molluscan host monitoring and control activities.

Cell-free DNA from bile outperformed plasma as a potential alternative to tissue biopsy in biliary tract cancer

BACKGROUND

Biliary tract cancers (BTCs) are rare and highly heterogenous malignant neoplasms. Because obtaining BTC tissues is challenging, the purpose of this study was to explore the potential roles of bile as a liquid biopsy medium in patients with BTC.

PATIENTS AND METHODS

Sixty-nine consecutive patients with suspected BTC were prospectively enrolled in this study. Capture-based targeted sequencing was performed on tumor tissues, whole blood cells, plasma, and bile samples using a large panel consisting of 520 cancer-related genes.

RESULTS

Of the 28 patients enrolled in this cohort, tumor tissues were available in eight patients, and plasma and bile were available in 28 patients. Somatic mutations were detected in 100% (8/8), 71.4% (20/28), and 53.6% (15/28) of samples comprising tumor tissue DNA, bile cell-free DNA (cfDNA), and plasma cfDNA, respectively. Bile cfDNA showed a significantly higher maximum allele frequency than plasma cfDNA (P = 0.0032). There were 56.2% of somatic single-nucleotide variant (SNVs)/insertions and deletions (indels) shared between bile and plasma cfDNA. When considering the genetic profiles of tumor tissues as the gold standard, the by-variant sensitivity and positive predictive value for SNVs/indels in bile cfDNA positive for somatic mutations were both 95.5%. The overall concordance for SNVs/indels in bile was significantly higher than that in plasma (99.1% versus 78.3%, P < 0.0001). Moreover, the sensitivity of CA 19-9 combined with bile cfDNA achieved 96.4% in BTC diagnosis.

CONCLUSION

We demonstrated that bile cfDNA was superior to plasma cfDNA in the detection of tumor-related genomic alterations. Bile cfDNA as a minimally invasive liquid biopsy medium might be a supplemental approach to confirm BTC diagnosis.

Computed tomography-identified phenotypes of small airway obstructions in chronic obstructive pulmonary disease

ABSTRACT

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characteristic of small airway inflammation, obstruction, and emphysema. It is well known that spirometry alone cannot differentiate each separate component. Computed tomography (CT) is widely used to determine the extent of emphysema and small airway involvement in COPD. Compared with the pulmonary function test, small airway CT phenotypes can accurately reflect disease severity in patients with COPD, which is conducive to improving the prognosis of this disease. CT measurement of central airway morphology has been applied in clinical, epidemiologic, and genetic investigations as an inference of the presence and severity of small airway disease. This review will focus on presenting the current knowledge and methodologies in chest CT that aid in identifying discrete COPD phenotypes.

FYN promotes gastric cancer metastasis by activating STAT3-mediated epithelial-mesenchymal transition

Gastric cancer is one of the most lethal cancers worldwide. FYN, a gene that is differentially expressed in gastric cancer, is considered a critical metastasis regulator in several solid tumors, but its role in gastric cancer is still unclear. This study aimed to evaluate the role of FYN and test whether FYN promotes migration and invasion of gastric cancer cells in vitro and in vivo via STAT3 signaling. FYN was overexpressed in gastric cancer and positively correlated with metastasis. FYN knockdown significantly decreased cancer cell migration and invasion, whereas FYN overexpression increased cancer migration and invasion. Genetic inhibition of FYN decreased the number of metastatic lung nodules in vivo. Several epithelial-mesenchymal transition markers were positively correlated with FYN expression, indicative of FYN involvement in this transition. Furthermore, gene set enrichment analysis of a Cancer Genome Atlas dataset revealed that the STAT3 signaling pathway was positively correlated with FYN expression. STAT3 inhibition reversed the FYN-mediated epithelial-mesenchymal transition and suppressed metastasis. In conclusion, FYN promotes gastric cancer metastasis possibly by activating STAT3-mediated epithelial mesenchymal transition and may be a novel therapeutic target for gastric cancer.

[Effects of girdling and defoliation on the growth of female cones and branches and nutrient content in different tissues and organs of Pinus koraiensis.]

To explore the nutrient source and supply-demand relationship of the female cone deve-lopment and new shoot growth of Pinus koraiensis, reproductive mother branches were experimentally girdled, defoliated, and under the combination of both treatments. The effects of different treatments on the female cones development, branch growth and the content of carbohydrate (NSC), nitrogen (N) and phosphorus (P) in different tissues and organs were measured. The results showed that girdling significantly affected female cone development, new shoot growth, and the contents of NSC, N and P in different tissues and organs, while defoliation treatment had limited effect. The NSC content in the mother branch xylem and phloem after girdling were significantly lower than that of the control (CK, ungirdling+0% defoliation), and decreased significantly with the increases of the degree of defoliation. The NSC content in mother branch xylem and phloem of girdling+100% defoliation was 59.0% and 64.8% lower than that of CK, respectively. The deficiency of NSC resulted in the death of mother branches and new shoots and the abortion of female cone. Under girdling treatment, the contents of N and P in xylem and phloem of mother branches of 0%, 50% and 100% defoliation treatment were significantly higher than that of CK. The contents of N and P in xylem of mother branches were 17.3%, 18.2% and 24.3% and 17.9%, 7.1% and 3.6% higher than those of CK, respectively. The contents of N and P in phloem of mother branches was 39.3%, 35.2% and 48.9% and 31.0%, 28.2% and 14.8% higher than those of CK, respectively. The female cone development and new shoot growth of P. koraiensis consumed a large amount of NSC, N and P. The carbohydrates and mineral nutrients manufactured or stored in the mother branches could not meet the needs of female cone development and new shoot growth, and thus they need to be imported from other tissues.

Effects of environmental chemicals on the proliferation and differentiation of neural stem cells

The objective of the present study was to explore the effects of environmental chemicals, such as methyl mercury, paraquat, and bisphenol A, on cell proliferation and apoptosis, as well as the expression levels of neuronal differentiation-related genes in neural stem cells (NSCs). NSCs originated from human umbilical cord blood (HUCB-NSCs) were used as cell models in the current study. CCK-8 and flow cytometry experiments were performed to assess the effects of methyl mercury, paraquat, and bisphenol A on the proliferation and apoptosis of HUCB-NSCs at different processes, including proliferation and differentiation stages. The expressions of neuronal differentiation-related genes were determined by reverse transcription-polymerase chain reaction and western blot analysis. The results showed that methyl mercury, paraquat, and bisphenol A treatments significantly inhibited cell proliferation and induced cell apoptosis in HUCB-NSCs, as well as decreased the expressions of Oct4, Gdf3, and Sox1, whereas increased Pax6 and Ngn1 expressions at both mRNA and protein levels. In conclusion, this study demonstrates that environmental chemicals can impair the proliferation and differentiation of NSCs, which may cause abnormal development of the nervous system.

Preoperative intravenous flurbiprofen reduces postoperative pain and inflammatory cytokines in elderly patients after hip arthroplasty

Effect of flurbiprofen on the postoperative cognition and inflammatory cytokines in elderly patients after hip arthroplasty was investigated. Elderly patients undergoing replacement of total hip were randomly divided into three groups of equal size (n=60). A control group (control) received no treatment before or at the end of surgery. The other two groups, PRE and INTRA, received 50 mg flurbiprofen intravenously 15 min before the surgery and 30 min before the end of surgery, respectively. The pain score was evaluated by a visual analog scale (VAS) at the following time-points: 24 h before surgery (T0), and 3 h (T1), 12 h (T2) and 24 h (T3) after surgery. Peripheral venous blood was collected at T0, T1, T2 and T3. Cognitive function was assessed by mini-mental state examination (MMSE) at the time of T0, T1, T2 and T3. The serum concentration of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), IL-6, and Cox-2 were measured using enzyme linked immunosorbent assay (ELISA). The VAS scores and the release of pro-inflammatory cytokines in the PRE and INTRA groups were less than those in the control group at T1, T2 and T3. The MMSE scores in PRE and INTRA groups were significantly higher than those in the control group at T1, T2 and T3. The PRE group showed a lower VAS score, release of pro-inflammatory cytokines and higher MMSE scores at T1, T2 and T3 than the control and INTRA groups. Intravenous flurbiprofen administration reduces postoperative pain and flammatory response after hip arthroplasty. Moreover, flurbiprofen is more effective when given preoperatively than intraoperatively.

[Pathologic subtyping of primary lymphoma of breast and prognostic analysis]

Objective: To investigate the pathological types and prognostic factors of primary lymphoma of breast (PLB). Methods: The clinical pathological data of 115 cases of PLB during October 2006 to October 2016 were retrospectively analyzed, and the basic clinical and pathological data, pathology types and the immunohistochemical slides by EliVision two-step method for staining were summarized. Results: Almost all the patients were women (113/115), and the median age was 52 years old (range: 27 to 81 years old). The main symptom was painless progressive mass in breast. Ten cases (8.7%) showed B symptoms. The masses were mainly confined to the unilateral breast (80.9%, 93/115), of which 22 cases showed axillary lymph nodes enlargement in the same side. The average diameter of masses was 3.0 cm (range from 0.5 to 9.0 cm). There is no differences between the sides (left or right). Pathologically, 106 cases (92.2%) were mature non-Hodgkin's B-cell lymphomas, of which there were mainly diffuse large B cell lymphoma (DLBCL, 64.3%) and mucosa associated lymphoid tissue (MALT) extranodal marginal lymphoma (17.4%). Five cases (4.4%) were mature T/NK cell lymphomas, including extranodal nasal NK/T cell lymphoma (1.7%), peripheral T-cell lymphoma non-specific type (0.9%), subcutaneous panniculitis-like T cells lymphoma (0.9%) and undivided (0.9%). Four cases were lymphoblastic lymphoma. According to Ann Arbor staging criteria, 93 cases were stage ⅠE (6 cases were stage ⅠEB), 22 cases were stage ⅡE (4 cases were stage ⅡEB). Ninety-two cases were followed 1 to 122 months (median: 36 months). The five-year overall survival rate was 85.3%, and 13 patients dead. B symptom was one of the factors that affect the prognosis (P<0.05), but the pathological type has no relationship with the prognosis (P>0.05). Conclusions: PLB is relatively rare, the main clinical manifestation is painless mass, which is difficult to distinguish with breast carcinoma. The most common type is DLBCL, followed by MALT lymphoma, while T cell lymphoma is rarely seen. PLB is early stage tumor with good prognosis, while patients with B symptom turn out to suffer worse prognosis.

[High expression of hnRNPAB/Kap1 together promote poor prognosis in HCC]

Objective: To further understand the interaction protein spectrum of heterogeneous ribonucleoprotein AB (hnRNP AB), and to investigate their clinical significance in hepatocellular carcinoma (HCC). Methods: We carried out mass spectrometry to reveal the specific peptides of KRAB-associated protein 1 (Kap1) and hnRNPAB, and verified their interaction by immunocoprecipitation and western blotting. Expression of hnRNPAB/Kap1 proteins were detected by immunohistochemical staining in the tissue microarrays. Categorical data were analyzed by the chi square test or Fisher exact test; enumeration data between groups were compared using Student t-test or Wilcocon signed rank test; the cumulative recurrence and survival rates were evaluated using the Kaplan-Meier method and the differences were assessed using the log-rank test. Results: We identified Kap1 as a molecular partner for hnRNPAB in HCCLM3 cells and HepG2 cells as well. We found that the 5-year survival rate of the Kap1high patients was significantly lower than the survival rate of those of the Kap1low group (36% vs 59% , HR = 1.67, P < 0.001). Similarly, Kap1high HCC patients had the poorest prognosis at 5-years, with higher cumulative recurrence rate than Kap1low patients (72% vs 54%, HR = 1.66, P = 0.001). Univariate and Multivariate analyses revealed that hnRNPAB /Kap1 alone (HR = 1.35 /1.28, P = 0.001) or in combination with Kap1 (HR =1.24 /1.27, P < 0.05) were independent prognostic indicators for overall survival and time to recurrence. Conclusion: In HCC cells, hnRNPAB and Kap1 form protein complexes. The expression levels of hnRNPAB alone or in combination with Kap1 in HCC patients are important because they provide not only a predictor for HCC prognosis but also a therapeutic target for future studies.

[The effect of paraquat on autophagy in human embryonic neural progenitor cells]

OBJECTIVE

To explore the effect of paraquat (PQ) on autophagy in human embryonic neural progenitor cells.

METHODS

Using ReNcell CX cell model. After treatment with various concentration (0.00, 1.00, 10.00 and 100.00 μmol/L) of PQ, CCK8 assay was used to detect the cell viability, the transmission electron microscope was used to observe the the cell ultrastructure, the real-time polymerase chain reaction (RT-PCR) was adopted to detect mRNA expression of autophagy related genes which including LC3, Atg12, Atg5, beclin1, Atg7 and mTOR and apoptosis related genes Bax and Bcl-2.

RESULTS

The cell viability was significantly inhibited after administered with 100.00 μmol/L of PQ (P<0.01). The mRNA expression of Beclin1 was significantly up-regulated and the emergency of autophagosome were observed at the concentration of 1.00 μmol/L group, while mild cell apoptosis, significantly up-regulated Atg5, Atg8, Atg7 and Atg12 mRNA expression as well as down-regulated expression of mTOR and Bax were detected at the 10.00 μmol/L of PQ group, howere, the obvious apoptosis and the up-regulated mRNA expression of mTOR and Bax were observed at the 100.00 μmol/L of PQ group, the mRNA expression of Bcl-2 were all down-regulated after administered with 1.00, 10.00 and 100.00 μmol/L of PQ and reached the lowest level at the concentration of 10.00 μmol/L.

CONCLUSION

PQ can induced autophagy at the low concentration in ReNcell CX cell and autophagy might serve as a protective mechanism to ameliorate PQ-induced cytotoxic effects but apoptosis will be induced at the 100 μmol/L concentration.

[Effect of fluorochloridone on oxidative stress in primary co-cultured sertoli-germ cell of rat]

Objective: To explore effect of fluorochloridone on primary co-cultured sertoli-germ cell of rat and its possible mechanism. Methods: primary co-cultured sertoli-germ cell was made by two steps of en-zyme digestion with SD rat testes, after 24h of Sertoli-germ cell isolation, A 0.1% DMSO solvent control group and three FLC exposure groups (10^-6、10^-7、10^-8 mol/L) were selected, cultured cell for 24h, then MTT assay and index detection of oxidative stress were performed. Results: The mortality of primary co-cultured sertoli-germ cell exposed to 10^-6 mol/L FLC was significantly higher than control group and FLC exposure groups (10^-7、10^-8 mol/L) (P<0.05) . 10^-6 mol/L FLC reduced enzyme activity of CAT, SOD and GSH. Px, depressed GSH level, el-evated MDA level, and had significant difference than control group and FLC exposure groups(10^-7、10^-8 mol/L) (P<0.05) . 10^-7 mol/L FLC decreased enzyme activity of CAT than control group, depressed enzyme activity of SOD than 10^-8 mol/L FLC, lowered GSH level than control group and FLC exposure groups (10^-8 mol/L) , and had statistical difference (P<0.05) . Conclusion: FLC can damage primary co-cultured sertoli-germ cell of rat, its possible mechanism is relevant to oxidative stress.

DNA Barcoding of genus Hexacentrus in China reveals cryptic diversity within Hexacentrus japonicus (Orthoptera, Tettigoniidae)

DNA barcoding has been proved successful to provide resolution beyond the boundaries of morphological information. Hence, a study was undertaken to establish DNA barcodes for all morphologically determined Hexacentrus species in China collections. In total, 83 specimens of five Hexacentrus species were barcoded using standard mitochondrial cytochrome c oxidase subunit I (COI) gene. Except for Hexacentrusjaponicus, barcode gaps were present in the remaining Hexacentrus species. Taxon ID tree generated seven BOLD’s barcode index numbers (BINs), four of which were in agreement with the morphological species. For Hexacentrusjaponicus, the maximum intraspecific divergence (4.43%) produced a minimal overlap (0.64%), and 19 specimens were divided into three different BINs. There may be cryptic species within the current Hexacentrusjaponicus. This study adds to a growing body of DNA barcodes that have become available for katydids, and shows that a DNA barcoding approach enables the identification of known Hexacentrus species with a very high resolution.

Deletion of the lmna gene induces growth delay and serum biochemical changes in C57BL/6 mice

The A-type lamin deficient mouse line (Lmna^−/−) has become one of the most frequently used models for providing insights into many different aspects of A-type lamin function. To elucidate the function of Lmna in the growth and metabolism of mice, tissue growth and blood biochemistry were monitored in Lmna-deficient mice, heterozygous (Lmna^+/−) and wide-type (Lmna^+/+) backcrossed to C57BL/6 background. At 4 weeks after birth, the weight of various organs of the Lmna^−/−, Lmna^+/− and Lmna^+/+ mice was measured. A panel of biochemical analyses consisting of 15 serological tests was examined. The results showed that Lmna deficient mice had significantly decreased body weight and increased the ratio of organ to body weight in most of tissues. Compared with Lmna^+/+ and Lmna^+/− mice, Lmna^−/− mice exhibited lower levels of ALP (alkaline phosphatase), Chol (cholesterol), CR (creatinine), GLU (glucose), HDL (high-density lipoprotein cholesterol) and higher levels of ALT (alanine aminotransferase) (p<0.05). Lmna^−/− mice displayed higher AST (aspartate aminotransferase) values and lower LDL (lowdensity lipoprotein cholesterol), CK-MB (creatine kinase-MB) levels than Lmna^+/+ mice (p<0.05). There were no significant differences among the three groups of mice with respect to BUN (blood urea nitrogen), CK (creatine kinase), Cyc C (cystatin C), TP (total protein), TG (triacylglycerols) and UA (uric acid) levels (p>0.05). These changes of serological parameters may provide an experimental basis for the elucidation of Lmna gene functions.

Gene polymorphisms associated with susceptibility to coronary artery disease in Han Chinese people

This study investigated 5 single nucleotide polymorphism (SNP) haplotypes in susceptibility genes for coronary artery disease (CAD) and the putative involvement of these SNPs in CAD in the Chi-nese Han population. From March 2008 to June 2009, we selected 119 CAD patients and 115 subjects not related to the CAD of Chinese Han or-igin as controls. The SNP genotypes were performed by multiplex SNaP-shot technology. The HNRPUL1 gene rs11881940T and GATA2 gene rs3803T loci were highly correlated with CAD (P < 0.05). rs10757278G increased the risk of CAD in patients indicated by an odds ratio (OR) = 1.242 [95% confidence interval (CI) = 1.04-1.49]; rs11881940T and rs3803T were protective factors for CAD with ORs = 0.767 (95%CI = 0.61-0.97) and 0.53 (95%CI = 0.40-0.72), respectively. Analysis of the rs10757278, rs11881940 and rs3803 loci showed that haplotypes ATC (OR = 4.26; 95%CI = 2.85-6.40, P < 0.01), GAC (OR = 1.50; 95%CI = 1.25-1.81, P < 0.01) and GAT (OR = 1.53; 95%CI = 1.12-2.09, P < 0.01) were CAD risk factors, whereas GTC was protective (OR = 0.48; 95%CI = 0.32-0.72, P < 0.01). ATC and glucose were positively correlated (OR = 1.91; 95%CI = 1.01-3.61, P < 0.05). GAT was a risk factor for hyper-tension (OR = 2.86; 95%CI = 1.40-5.83, P < 0.01). In conclusion, poly-morphisms and haplotype analysis of susceptibility genes for CAD can improve predicting this disease and will enable early diagnosis of CAD.

Complete mitochondrial genome of Locusta migratoria migratoria (Orthoptera: Oedipodidae): three tRNA-like sequences on the N-strand

The complete 16053 bp mitochondrial genome (mitogenome) sequence of Locusta migratoria migratoria has been determined. This mitogenome contains the base compositional biases and codon usage typical of metazoans, and the RSCU values indicate a negative correlation with the C and G contents in codon. The orientation and gene order of the L. migratoria migratoria is identical to Locusta migratoria migratoiodes. An unusual feature of the L. migratoria migratoria mitogenome is the presence of three tRNA-like structures on the N-strand: one tRNA(Ile)-like and two tRNA(Leu(CUN))-like sequences. The tRNA-like sequences have proper folding structures and anticodons sequences. Two repeated DNA sequences, Rpt I and Rpt II, were found in the A+T-rich region of the L. migratoria migratoria mitogenome. Both repeated sequences have various features. In the 5' region of Rpt I, a 51 bp fragment is localized in the srRNA gene; and there are two tandemly sub-repeated DNA sequences (sub-Rpts), Rpt 1-4, within Rpt I and Rpt II. One stem-loop structure on the N-strand that may be involved in the N-strand replication initiation was found in the A+T-rich region.

[Involvement of excitatory amino acid system in astrocytes activation caused by dimethoate]

OBJECTIVE

To study the involvement of excitatory amino acid system in astrocytes activation caused by dimethoate.

METHODS

Pure-cultured astrocytes were gained by three passages from primary cultured rat nerve cells, then treated with 10(-6),10(-5),10(-4) mol/L dimethoate for 48 h, 50 micromol/L and 100 micromol/L MK801, a NMDA receptor blocker, was used to intervene the effects induced by 10(-4) mol/L dimethoate. HPLC-FLD was utilized to measure the concentrations of excitatory amino acid (EAA), RT-PCR was used to detect the expression levels of NR2B, GLT-1, GLAST, GFAP and S100beta mRNA, and immunofluorescence staining method was applied to measure the expression levels of GFAP and S100beta proteins.

RESULTS

The expression levels of GLAST mRNA in all exposure groups were 67.8%, 68.6% and 76.2% of control level, respectively, which were significantly lower than that of control group (P < 0.05); The concentrations of EAA significantly decreased in 10(-4) mol/L dimethoate group, as compared with control group (P < 0.01); the expression levels of GFAP mRNA in 10(-4) mol/L dimethoate group, of S100beta mRNA in 10(-5) mol/L dimethoate group, of GFAP protein in 10(-4) mol/L and 10(-5) mol/L dimethoate groups and S100beta protein in 10(-4) mol/L dimethoate group were significantly higher than those in control group (P < 0.01). The expression levels of GLT-1 and GLAST mRNA in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups increased significantly, as compared with 10(-4) mol/L dimethoate group (P < 0.01), the expression levels of NR2B mRNA in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups increased significantly, as compared with control group (P < 0.05 or P < 0.01); the concentration of Glu in 10(-4) mol/L dimethoate plus 100 micromol/L MK801 group increased significantly, as compared with 10(-4) mol/L dimethoate group (P < 0.01); the expression levels of GFAP mRNA and protein in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups decreased significantly (P < 0.01); S100beta protein expression level in 50 micromol/L MK801 intervention group was significantly higher than thatl in control group (P < 0.01).

CONCLUSION

Excitatory amino acid system involved in astrocytes activation caused by dimethoate. MK801 was useful to control astrocytes gliosis.

[Genetic differentiation among different geographic populations of Gampsocleis sedakovii]

The mitochondrial cytochrome oxidase I (mtDNA-COI) gene was used to investigate the intraspecific genetic subdivision among 12 geographical populations of Gampsocleis sedakovii distributed in Jilin, Liaoning, Inner Mongolia, Hebei, and Sichuan provinces, China. As for the 626 bp mtDNA-COI sequences of 36 individuals, 29 haplotypes and 71 (11.3%) polymorphic sites were detected, including 37 parsimony informative and 34 singleton variable sites. The results of the analysis of molecular variance (AMOVA) showed that the percentage of variation within populations (37.23%) was less than that among populations. The Fst value was 0.62770 (P< 0.001), and the genetic divergence among populations was significant. Maximum parsimony (MP) analysis revealed two clearly differentiated branch (Ⅰ and Ⅱ) with high bootstrap support (100%). However, these two branches did not correspond in the subspecies distinction based on morphological character. Based on the habitats analysis, we preliminary inferred that morphological divergence between Gampsocleis se-dakovii sedakovii and Gampsocleis sedakovii obscura was the result of habitat dissimilarity. The majority of the G. se-dakovii individuals collected in NTL (Tongliao, Inner Mongolia) were identified as the members of branch Ⅱ, but one individual (NTL-3) belonged to branch Ⅰ. Thus, at least this locality was occupied by two phylogenetically independent individuals. Haplotypes (H10) were shared by three localities, NTL, NEWK (Ewenke, Inner Mongolia) and JJL (Jilin, Jilin), indicated that they shared a common ancestor. We approved that Northeastern China (Manchuria China) was the center of G. sedakovii genetic differentiation, but disapproved the subspecies distinction based on morphological character.

[Role of connective tissue growth factor and α-smooth muscle actin in pulmonary fibrosis among acute paraquat poisoned rats]

OBJECTIVE

to observe the expression of the connective tissue growth (CTGF) and a smooth muscle actin (α-SMA) in acute paraquat (PQ) poisoned rats and investigate the mechanism of paraquat-induced pulmonary fibrosis.

METHODS

sprague-Dawley rats were randomly divided into two experimental groups: control group (6 rats) and PQ group (56 rats). On the 3rd, the 7th, the 14th, the 28th and the 56th day after exposure, the expression of CTGF and α-SMA were evaluated by SABC Immunohistochemistry and Western blot; and the relationship of the expression with pathologic score, hydroxyproline were also analyzed, respectively. The lung pathological changes of rats were observed and pathological evaluation was made.

RESULTS

it was similar that the expression pattern of CTGF, α-SMA detected by immunohistochemistry and Western blot. With the time passing, their expression in PQ group increased gradually compared with control group (P < 0.05 or P < 0.01). The increasing extent of CTGF, α-SMA were gentle on the 3rd, the 7th day. While their increasing extent was rapid from the 14th to the 56th day. CTGF was positively correlated with α-SMA, pathologic score and hydroxyproline respectively (r = 0.74, r = 0.87, r = 0.71, P < 0.05 or P < 0.01). Meanwhile, the histological changes such as lung fibroblast proliferation, disorganized collagen fibers were observed in PQ group.

CONCLUSION

CTGF and α-SMA could play an important role in the development of pulmonary fibrosis caused by paraquat poisoning; CTGF may promote the transformation of fibroblasts to myofibroblasts and further strengthen the ability of synthesis collagen and extracellular matrix.

[Effects of 1-bromopropane on neurological and hematological changes of female exposed workers]

OBJECTIVE

To investigate the health effects of 1-bromopropane (1-BP) on female exposed workers.

METHODS

Four 1-BP manufacturing plants were investigated. Workers were interviewed with questionnaire and examined with neurobehavioral core test battery, nerve conduction velocity tests of nervus tibialis and nervus suralis, vibration sensation test, hematological and biochemical tests. Ambient 1-BP concentration was measured with detection tube, and time-weighed average levels of individual workers were estimated with passive samplers.

RESULTS

1-BP concentration in the plants ranged from 0 to 402.40 mg/m3 (Geomean 32.19 mg/m3). Time-weighted average exposure levels (TWA-8 h) ranged from 0.35 to 535.19 mg/m3 (Geomean 14.08 mg/m3). Compared with the control group, 1-BP exposed workers showed reduced motor nerve conduction velocity [(44.8 +/- 8.7) m/s] and sensory nerve conduction velocity [(45.5 +/- 4.9) m/s], prolonged distal latency [(7.5 +/- 2.1) ms], reduced toe vibration perception, and altered neurobehavior parameters(POMS vigor, tension, anxiety, confusion) significantly (P < 0.05). As to hematological and biochemical indicators, the exposed workers showed decreased white blood cell count [(5.6 +/- 2.17) x 10(3)/microl], red blood cell count [(3.9 +/- 0.4) x 10(6)/microl], hemoglobin [(121.1 +/- 14.5) g/L] and creatine kinase [(82.0 +/- 27.5) IU/L] (P < 0.05), and increased serum total protein (8.0 +/- 0.5 g/dl), lactate dehydrogenase [(335.2 +/- 356.6) IU/L], thyroid-stimulating hormone [(3.6 +/- 2.3) microIU/ml] and follicle-stimulating hormone levels (18.7 +/- 24.4 mIU/ml) (P < 0.05).

CONCLUSION

1-BP exposure may affect peripheral nerves and central nervous system, and lead to abnormal hematological and biomedical indicators.

[Effect of neonatal exposure to environmental pollutants on the DNA methylation of rat testis]

OBJECTIVE

To investigate the effects of neonatal exposure of DNA methylation inhibitor, Cadmium and PCB153 on DNA methylation, apoptosis and spermatogenesis in SD rats.

METHODS

Neonatal SD rats were randomly divided into 10 groups and received oral administrations of PCB153 (0.025, 0. 250, 2.500 mg/kg), or Cadmium (1, 2, 4 mg/kg), or positive control 5-Aza-CdR (0.025, 0.250 mg/kg), or vehicle control for five days from PND3. Half of the rats were killed 24 h after the last administration. The remains were fed until 12 weeks. Sperm numbers, apoptosis and DNA methylation levels in testis were investigated.

RESULTS

The daily sperm production was significantly decreased in each neonatal exposed group (P < 0.05). Neonatal rats exposed to 5-Aza-CdR and Cadmium reduced the global DNA methylation level, increased apoptosis, while PCB153 exposure did not significantly change DNA methylation and apoptosis.

CONCLUSION

Neonatal rats exposed to chemicals could reduce spermatogenesis via multiple pathways. Lower DNA methylation and increased neonatal apoptosis were suggested as one of the causes.

[Influence of pyrrolidine dithiocarbamate (PDTC) on expression of transforming growth factor beta(1), matrix metalloproteinase-2 and tissue inhibitor-1 of metalloproteinase in rats with pulmonary damage induced by paraquat]

OBJECTIVE

To investigate the influence of pyrrolidine dithiocarbamate (PDTC) on the expression of transforming growth factor beta(1) (TGF-beta(1)), matrix metalloproteinase-2 (MMP-2) and tissue inhibitor-1 of metalloproteinase (TIMP-1) in rats with pulmonary damage induced by paraquat (PQ).

METHODS

Fifty-four healthy male SD rats were randomly assigned into the control group (normal saline), the PQ-treatment groups (4 groups) and the PDTC treatment groups (4 groups). Except the rats in the control group, the rats in the PQ group were gavaged only with 40 mg/kg PQ, and PDTC group with 40 mg/kg PQ plus immediate injection 120 mg/kg PDTC (i.p). On the 3rd, the 7th, the 14th and 28th day after treatments, one group rats of each treatments were sacrificed and lung and blood samples were collected. The level of TGF-beta(1) protein in the plasma, the mRNA expression of TGF-beta(1), MMP-2 and TIMP-1 were evaluated using RT-PCR and real-time quantitative PCR, while pathological changes of lung were examined under optical microscope and electrical microscope.

RESULTS

The TGF-beta(1) protein, TGF-beta(1) and MMP-2 mRNA expression were increased significantly in the earlier stage and then decreased after PQ administration (P < 0.05 or P < 0.01), while the mRNA level of TIMP-1 was augmented continuously (P < 0.01) throughout the study compared to the control group. In comparison with the PQ group, in the PDTC treatment group, the TGF-beta(1) mRNA expression on the 3rd and the 14th day, 0.54 +/- 0.08 and 0.72 +/- 0.04 respectively, the MMP-2 mRNA expression on the 7th and 14th day, 1.62 +/- 0.50 and 1.97 +/- 0.34 respective-ly, and the TIMP-1 mRNA on the 7th and 21st day, 1.79 +/- 0.21 and 2.00 +/- 0.34 respectively, were significantly decreased (P < 0.05 or P < 0.01).

CONCLUSION

PDTC could attenuate paraquat-induced up-regulation of TGF-beta(1) and its mRNA expression, MMP-2 and TIMP-1 mRNA levels, which indicates that PDTC may exert its protective effects on paraquat-induced pulmonary damage by alleviating the earlier inflammation damage and adjust-ing the balance between MMPs and TIMPs. However, further studies are still warranted to investigate and clarify the underlying mechanisms involved in this complicated process.

Carboxylic esterase and its associations with long-term effects of organophosphorus pesticides

OBJECTIVE

To examine a) the effect of organophosphorus pesticide exposure on activity of carboxylic esterases, namely butyrylcholinesterase (BChE), carboxylesterase (CarbE) and paraoxonase (PonE); and b) the association of polymorphisms of BChE and PonE with individual genetic susceptibility to organophosphorus pesticide exposure.

METHODS

A cross-sectional study was conducted in 75 workers exposed to organophosphorus pesticides and 100 non-exposed controls. The serum activity of these enzymes was measured. Variant forms of BCHE-K, PON-192, and PON-55 were detected. A symptom score was developed as a proxy measure of clinical outcomes.

RESULTS

Activities of both BChE and CarbE were lower in exposed workers (27.3+/-21.65 nmolxh(-1)xmL(-1) and 235.6+/-104.03 nmolxmin(-1)xmL(-1)) than in non-exposed workers (78.313+/-30.354 nmolxh(-1)xmL(-1) and 362.681+/-194.997 nmolxmin(-1)xmL(-1)). The activity of PonE was not associated with exposure status. The AChE activity in the exposed workers with BCHE-K genotype UU (61 cases), genotype UK (12 cases) and genotype KK (2 cases) was 105.05, 84.42 and 79.00 mmolxh(-1)xmL(-1), respectively and the accumulative symptom scores were 3.74, 9.17, and 12.50 accordingly. The AChE activity in the exposed workers with PON-192 genotypeBB (37), genotype AB (27) and genotype AA (11) was 116.8, 91.2, and 72.3 mmolxh(-1)xmL(-1), respectively and the symptom scores were 2.00, 6.74, and 9.73 accordingly. The AChE activity in those with PON-55 genotype LL (70) and genotype LM (5) was 102.4 and 82.8 mmolxh(-1)xmL(-1) and the symptom scores were 4.53 and 9.20. The symptom score was the highest in individuals with abnormal homozygote for each of the three gene loci.

CONCLUSIONS

Long-term exposure to organophosphorus pesticides can inhibit BChE and CarbE activity, but exerts no inhibitory effect on PonE activity. Different genotypes of BCHE-K, PON-192, and PON-55 may be related to the severity of adverse health effects of organophosphorus pesticide exposure. Implications of potentially higher susceptibility of workers with mutant homozygotes should be evaluated to reduce health risks.

[Effect of dimethoate on serum monoamines neurotransmitters in rats]

OBJECTIVE

To study the effect of dimethoate on the monoamine Neurotransmitters, including norepinephrine (NE), epinephrine (E), serotonin (5-HT), dopamine (DA) and its metabolite (3, 4-hydroxyphenylacetic acid, DOPAC) in the serum of rats and furthermore to explore the non-cholinergic mechanism of organophosphate induced toxicity.

METHODS

Groups of rats were treated with saline and 38.9, 83.7 and 180 mg/kg dimethoate respectively and were decapitated at the different time course from 0.5 to 24 hours after the administration. The monoamines neurotransmitters were determined by the reverse-phase high-performance liquid chromatography with the electrochemical detection.

RESULTS

The serum concentrations of DA (8.42% - 248.42% of the control), DOPAC (17.22% - 68.21% of the control) increased, according with the DM dosage and the exposure time, while the levels of NE (9.65% - 38.26% of the control) and E (11.00% - 32.62% of the control) contents decreased at the same time.

CONCLUSION

These findings indicate that dimethoate induced toxic effects can alter the monoamine levels at the different dosage and the time exposure in the serum of rats. It suggests that some non-cholinergic mechanisms may be involved in the dimethoate intoxication.

[Effect of environmental contaminants on DNA methyltransferase activity of mouse preimplantation embryos]

OBJECTIVE

To investigate the effect of environmental contaminants on development rate and DNA methyltransferase activity of preimplantation embryos.

METHODS

1-cell embryos were collected from oviduct, in vitro cultured to blastocyst stage in media with or without environmental contaminants. The development rate and DNA methyltransferase activity were determined.

RESULTS

The development rates of preimplantation embryos from 1-cell stage to blastocyst stage were not affected by the exposed compounds. However, 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) significantly increased the DNA methyltransferase activity, 2, 2', 3, 3' 4, 4'-polychlorinated biphenyl (PCB153) and diethylstilbestrol (DES) significantly decreased the DNA methyltransferase activity, while p, p'- dichlorodiphenel ethylene (DDE) and dibutyl phthalate (DBP) did not change the DNA methyltransferase activity significantly.

CONCLUSION

Exposure to TCDD, DES, and PCB 153 alters the DNA methyltransferase activity in early development stage, which may induce the change of methylation status of genes and affect the development in the later stage.

Neurokinin 1 receptor expression and substance p physiological actions are developmentally regulated in the rabbit retina

We investigated the expression of the substance P (SP) receptor (the neurokinin 1 receptor, NK1 receptor) and SP functional effects in developing rabbit retinas. NK1 receptors in adult retinas were in a population of cone bipolar cells and in dopaminergic amacrine cells, as previously described. In contrast, at birth and at postnatal day (PND) 6, NK1 receptors were exclusively expressed by cholinergic amacrine and displaced amacrine cells. NK1 receptor expression in cholinergic cells was still observed at PND10 (eye opening), while at PND21 it was confined to cholinergic cells of the inner nuclear layer. Starting at PND10, NK1 receptors were also in bipolar cells and in dopaminergic amacrine cells. A fully mature NK1 receptor expression pattern was observed at PND35. Dopamine release was assessed in isolated retinas in the presence of SP, the NK1 receptor agonist GR73632 or the NK1 receptor antagonist GR82334. At PND35, extracellular dopamine was significantly increased by 10 microM SP or 0.01-100 microM GR73632, and it was decreased by 0.01-10 microM GR82334. No effects were detected in developing retinas up to PND21. Ca2+ imaging experiments were performed in single cholinergic cells identified by their "starburst" morphology in perinatal retinas. Intracellular Ca2+ levels were significantly increased by 1 microM SP or GR73632. This effect was reversibly inhibited by 1 microM GR82334. These data demonstrate that both NK1 receptor expression and SP physiological actions are developmentally regulated in the retina. SP neurotransmission in the immature retina may subserve developmental events, and SP is likely to represent an important developmental factor for the maturation of retinal neurons and circuitries.

A critical role of the strychnine-sensitive glycinergic system in spontaneous retinal waves of the developing rabbit

In the developing vertebrate retina, spontaneous electric activity occurs rhythmically in the form of propagating waves and is believed to play a critical role in activity-dependent visual system development, including the establishment of precise retinal and geniculate circuitry. To elucidate how spontaneous retinal waves encode specific developmental cues at various developmental stages, it is necessary to understand how the waves are generated and regulated. Using Ca(2+) imaging and patch clamp in a flat-mount perinatal rabbit retinal preparation, this study demonstrates that, in addition to the cholinergic system, a strychnine-sensitive system in the inner retina plays an obligatory and developmentally regulated role in the initiation and propagation of spontaneous retinal waves. This system, which is believed to be the glycinergic network, provided an excitatory drive during early retinal development. It then became inhibitory after postnatal day 1 (P1) to P2, an age when a number of coordinated transitions in neurotransmitter systems occurred concomitantly, and finally contributed to the complete inhibition and disappearance of spontaneous waves after P7-P9. This glycinergic contribution was notably distinct from that of the ionotropic GABAergic system, which was found to exert an inhibitory but nonessential influence on the early wave formation. Blocking glycine- and GABA-gated anion currents had opposing effects on spontaneous retinal waves between embryonic day 29 and P0, suggesting that Cl(-) transporters, particularly R(+)-butylindazone-sensitive K-Cl cotransporters, may have a synapse- and/or cell type-specific distribution pattern, in addition to an age-dependent expression pattern in the inner retina. Overall, the results revealed an important reliance of spontaneous retinal waves on dynamic and coordinated interactions among multiple, nonredundant neurotransmitter systems.

Coordinated transitions in neurotransmitter systems for the initiation and propagation of spontaneous retinal waves

Spontaneous waves of excitation in the developing mammalian retina are mediated, to a large extent, by neurotransmission. However, it is unclear how the underlying neurotransmitter systems interact with each other to play specific roles in the formation of retinal waves at various developmental stages. In particular, it is puzzling why the waves maintain a similar propagation pattern even after underlying neurotransmitter systems have undergone drastic developmental changes. Using Ca(2+) imaging and patch clamp in a whole-mount preparation of the developing rabbit retina, we discovered two dramatic and coordinated transitions in the excitatory drive for retinal waves: one from a nicotinic to a muscarinic system, and the other from a fast cholinergic to a fast glutamatergic input. Retinal waves before the age of postnatal day 1 (P1) were blocked by nicotinic antagonists, but not by muscarinic or glutamatergic antagonists. After P3, however, the spontaneous wave, whose basic spatiotemporal pattern remained similar, was completely inhibited by muscarinic or glutamate antagonists, but not by nicotinic antagonists. We also found that the muscarinic drive, mediated primarily by M1 and M3 receptors, was particularly important for wave propagation, whereas the glutamatergic drive seemed more important for local excitation. Our results suggest (1) a novel mechanism by which a neurotransmitter system changes its functional role via a switch between two completely different classes of receptors for the same transmitter, (2) the cholinergic system plays a critical role in not only early but also late spontaneous waves, and (3) the continued participation of the cholinergic system may provide a network basis for the consistency in the overall propagation pattern of spontaneous retinal waves.

Insights into rheumatoid arthritis derived from the Sa immune system

The Sa system is a recently described immune system that has a specificity and positive predictive value of nearly 100% for rheumatoid arthritis (RA) in Asia, Europe and the Americas. Its sensitivity of 30-40% suggests that it identifies a subset of RA patients. Anti-Sa antibodies are present from disease onset and are predictive of disease severity. The immune reactants are plentiful in the target tissue: antigen is present in the synovium, IgG antibody in the fluid. Immunologically, Sa is a hapten-carrier antigen in which vimentin is the carrier and citrulline is the hapten. The citrullination of vimentin is closely related to apoptosis, and citrullinated vimentin is extremely sensitive to digestion by the ubiquitous calpains. Nevertheless, Sa is found in only a few cell lines. Calpastatin, the natural specific inhibitor of calpains, is also a RA-associated, albeit non-specific, autoimmune system. Is it possible that calpain-related apoptotic pathways could be prominent in cells containing Sa? The task is to reconcile the specificity of Sa/citrullinated proteins in a multifactorial and polygenic disease such as RA.

Direct participation of starburst amacrine cells in spontaneous rhythmic activities in the developing mammalian retina

Spontaneous, rhythmic waves of excitation in the developing mammalian retina play a critical role in the formation of precise neuronal connectivity in the visual system. However, it is not known what circuits in the retina are responsible for the production of these waves. Using patch-clamp recordings in the whole-mount neonatal rabbit retina, this study reports that the displaced starburst amacrine cell, a unique cholinergic interneuron in the ganglion cell layer of the retina, undergoes rhythmic bursts of membrane depolarization with a frequency and duration similar to those of spontaneous retinal waves. Simultaneous patch-clamp recordings from pairs of neighboring starburst and ganglion cells show that the rhythmic activity in starburst cells is closely correlated with that in ganglion cells, and that the excitation in both cell types is most likely driven by synaptic input. However, in contrast to ganglion cells, displaced starburst cells usually do not generate spontaneous somatic action potentials. Instead, they seem to use subthreshold potentials (at least at the soma) to mediate the rhythmic excitation. The results suggest that acetylcholine is likely released rhythmically in the developing retina. Thus, starburst amacrine cells form the first identified network of retinal interneurons that directly participate in spontaneous rhythmic activities in the developing retina.

Starburst amacrine cells change from spiking to nonspiking neurons during retinal development

The membrane excitability of cholinergic (starburst) amacrine cells was studied in the rabbit retina during postnatal development. Whole-cell patch-clamp recordings were made from 110 displaced starburst cells in a thin retina] slice preparation of rabbits between postnatal days P1 and P56 old. We report that displaced starburst cells undergo a dramatic transition from spiking to nonspiking, caused by a loss of voltage-gated Na currents. This change in membrane excitability occurred just after eye opening (P10), such that all of the starburst cells tested before eye opening had conspicuous tetrodotoxin-sensitive Na currents and action potentials, but none tested after the first 3 postnatal weeks had detectable Na currents or spikes. Our results suggest that starburst cells use action potentials transiently during development and probably play a functional role in visual development. These cells then cease to spike as the retina matures, presumably consistent with their role in visual processing in the mature retina.

[Effects of lesion or stimulation of pituitary gland and hypothalamic arcuate nucleus on pain modulation in rats]

Relationship between pituitary gland and hypothalamic arcuate nucleus (ARC) in the modulation of pain threshold was investigated in Wistar rats with method of focal lesion and stimulation of pituitary gland. Experimental results indicated that electrolytic lesion of the pituitary intermediate and anterior lobes resulted in a decrease of pain threshold and disappearance of the analgesia immediately produced by ARC stimulation. Stimulation of the same area of pituitary gland could induce a delayed analgesia, which could be blocked by ARC lesion.

Neurotransmitter receptors of starburst amacrine cells in rabbit retinal slices

The receptor pharmacology of cholinergic ("starburst") amacrine cells was studied in a newly developed rabbit retinal slice preparation with whole-cell patch clamp. Displaced starburst cells were labeled with the fluorescent dye 4,6-diamidino-2-phenylindole (DAPI), and their dendritic morphology was identified in the slice with Lucifer yellow. Under conditions in which synaptic transmission was blocked by Cd2+, starburst cells responded vigorously to the bath-applied neurotransmitters GABA, glycine, and glutamate. The response to GABA consisted of an inward current and an increase in noise, which could be mimicked by the GABAA agonists muscimol and trans-4-aminocrotonic acid (TACA), but not by the GABAB agonist baclofen or the GABAC agonist cis-4-aminocrotonic acid (CACA). The GABA-evoked currents were reversibly inhibited by bicuculline and picrotoxin and had a reversal potential close to the chloride equilibrium potential. Noise analysis of GABA-activated whole-cell currents yielded elementary conductance estimates of 12.5 pS. Glycine (30-200 microM) also activated a Cl- conductance in starburst cells, which could be completely blocked by strychnine. The non-NMDA agonists kainate (KA, 30-100 microM) and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA, 60 microM) evoked robust responses, which were reversibly blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), and which reversed near the equilibrium potential for cations. NMDA coapplied with glycine in salines free of Cd2+ and Mg2+ elicited small but detectable responses. The I/V relation of the NMDA-evoked response showed a characteristic "J"-shaped region in a saline containing 1 mM Mg2+ and 0 Cd2+, indicating that NMDA receptors were present directly on starburst cells. This was consistent with our finding that whole-cell currents evoked by KA and NMDA had different noise characteristics. These results place new constraints on models of starburst cell function and suggest that GABA-mediated inhibition of the starburst cell itself may play an important role in directional selectivity in the retina.

Immunocytochemical study of lampbrush chromosomes of the urodele Pleurodeles waltl: axial granules are recognized by the mitosis-specific monoclonal antibody MPM-2

The lampbrush chromosomes of the urodele Pleurodeles waltl have been studied using the mitosis-specific monoclonal antibody MPM-2. Immunofluorescence studies revealed that MPM-2 stains structures associated with axial granules, numerous other chromomeres, telomeres and certain chiasmata. These structures showed a negative reaction with the anti-DNA monoclonal antibody AC-30-10. In course of meiotic condensation of the chromosomes, in growing and maturating oocytes, the number of such structures associated with the chromosome axis was found to diminish progressively. These granular structures have been found to be formed by fine fibrils about 5 nm in diameter. Immunogold labeling confirmed the results of immunofluorescence studies. MPM-2 was also found to stain two other types of structures observed in association with the lampbrush chromosome axis in P waltl, viz the sphere organelle (only in later stages of oogenesis) and the structure known as 'M' which is singular to this material.

Ligand-gated currents of alpha and beta ganglion cells in the cat retinal slice

1. We studied the receptor pharmacology of the ligand-gated currents of ON- and OFF- alpha and beta ganglion cells in a cat retinal slice preparation using the whole cell recording variation of the patch-clamp technique. Cat retinal slices were cut in N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) buffer and incubated in a bicarbonate-buffered solution. Ganglion cells were voltage clamped at -70 mV in HEPES-buffered Ringer solution. The pipette solution contained a low concentration of Cl- to distinguish mixed cationic from Cl(-)-mediated conductances, and Lucifer yellow (0.5%) was included for identification of the cell type. 2. In Ringer solution containing 1.2 mM Mg2+, current-voltage (I-V) curves of responses to the excitatory amino acid agonist (EAA) N-methyl-D-aspartate (NMDA) (200 microM) revealed a J-shaped function. In Mg(2+)-free Ringer solution containing 200 microM Cd2+ to block synaptic transmission, NMDA (200 microM) elicited an inward current 5-8 times larger at -70 mV. In both conditions I-V curves of the NMDA-induced currents reversed near 0 mV. These results suggest that there are NMDA EAA receptors present directly on the dendrites of alpha and beta ganglion cells. Responses to NMDA were blocked by +/- 2-amino-7-phosphonoheptanoic acid (AP7) (200 microM). 3. In Ringer solution containing 200-1,000 microM Cd2+ to block synaptic transmission, both ON- and OFF- alpha and beta cells responded to kainic acid (10-50 microM), alpha-amino-3-hydroxy-5-methylisoxazole-4-proprionic acid (AMPA) (20-70 microM), and quisqualic acid (0.1-30 microM) with inward currents that reversed near 0 mV. These responses were blocked by the quinoxaline EAA antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) (10 microM). The metabotropic agonists 1-aminocyclopentane-1,3-dicarboxylic acid (ACPD) (25 microM) and L-2-amino-4-phosphonobutyric acid (L-APB) (50 microM) and L-2-amino-4-phosphonobutyric acid (L-APB) (50 microM) in the presence of Cd2+ evoked little or no response for all cells tested. 4. In the presence of Cd2+, alpha and beta cells responded to gamma-amino-butyric acid (GABA) (200 microM) and glycine (200 microM) with inward currents that reversed near -35 mV, the calculated chloride equilibrium potential Ecl. Responses to GABA and glycine were both strongly desensitizing. (+)Bicuculline methyl chloride (20 microM) blocked an average of 90% of the inward current evoked by 200 microM GABA on all ganglion cell types.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino acid receptors of midget and parasol ganglion cells in primate retina

Primate retinas contain two major ganglion cell types. Midget (or P type) cells have relatively sustained responses to light; the amplitude and polarity of these responses vary with stimulus wavelength. Parasol (or M type) cells are more sensitive to stimulus contrast and respond more transiently but are not selective for color. Both types can be further subdivided into a and b subtypes, according to the level of their dendritic stratification in the inner plexiform layer. To determine whether differences in receptors for amino acid transmitters are the basis for any differences in ganglion cell light responses, we made whole-cell, patch-clamp recordings from identified ganglion cells in slice preparations of macaque and baboon retinas. We found that midget and parasol cells of both a and b types had similar responses to excitatory amino acids, including kainate, alpha-amino-3-hydroxy-5-methylisoxalzole-4-propionic acid, and N-methyl-D-aspartate, with reversal potentials near the equilibrium potential for cations. Kainate responses were blocked by 6,7-dinitroquinoxaline, and N-methyl-D-aspartate responses were blocked by D-(-)-2-amino-7-phosphonoheptanoic acid. The four types of ganglion cells also had similar responses to bath-applied inhibitory amino acids. All cells had both gamma-aminobutyric acid and glycine receptors with reversal potentials near the equilibrium potential for Cl-, and the relative amplitudes of the responses to excitatory and inhibitory amino acids were similar among the various cell types. These results suggest that the differences in response properties of the different classes of ganglion cells in primate retina may be determined, to a significant degree, by the properties of the amacrine and bipolar cells that provide their input rather than by the nature of their postsynaptic receptors.