Speciation and Potential Ecological Risk of Heavy Metals in Soils from Overlapped Areas of Farmland and Coal Resources in Northern Xuzhou, China.

Contamination caused by heavy metals (HMs) in soil of overlapped area of farmland and coal resources (OAFCR) has impact on crops. The concentrations and speciation of As, Cd, Cr, Cu, Pb and Zn were investigated in topsoil of an OAFCR in Xuzhou, China. The results showed that mean concentrations of all six metals were higher than the background values of Xuzhou city and Cd was moderate accumulated with the maximum Igeo equalled to 2.13. Cd showed moderate contamination level (IPi = 1.75) and potential ecological risk (Er = 44.06). Most of the total Cr, Cu, Ni, Pb, and Zn were presented in the residual forms (above 60%), and the percentages of reducible, oxidisable and residual forms of Pb were 23%, 21% and 43% respectively. Pb and Cd reflected a moderate degree of potential ecological risk and a considerable migration risk and ecotoxicity.

[Analysis of families with fetal congenital abnormalities but negative prenatal diagnosis by whole exome sequencing].

Objective: To evaluate the value of whole exome sequencing (WES) in prenatal clinical application. Methods: A total of 1 152 cases of congenital abnormal [including structural malformation, nuchal translucency (NT) thickening and intrauterine growth restriction] with traditional prenatal diagnosis [including G-band karyotype analysis and chromosome microarray analysis (CMA)] negative were analyzed. The congenital abnormal fetuses were divided into retrospective group and prospective group according to the time of WES detection, that is whether the pregnancy termination or not. According to the specific location of fetal malformation and their family history, the cohort was divided into subgroups. The clinical prognosis of all fetuses were followed up, and the effect of WES test results on pregnancy decision-making and clinical intervention were analyzed. According to the follow-up results, the data of fetuses with new phenotypes in the third trimester or after birth were re-analyzed. Results: Among 1 152 families who received WES, 5 families were excluded because of nonbiological parents. Among the remaining 1 147 families, 152 fetuses obtained positive diagnosis (13.3%,152/1 147), including 74 fetuses in the retrospective group (16.1%,74/460) and 78 fetuses in the prospective group (11.4%,78/687). In fetuses with negative CMA and G-band karyotype analysis results but new phenotypes in the third trimester or after birth, the positive rate by WES data re-analysis was 4.9% (8/163). A total of 34 (21.3%, 34/160) fetuses were directly affected by the corresponding positive molecular diagnosis. Among 68 cases of live births with diagnostic variation grade 4, 29 cases (42.7%, 29/68) received appropriate medical intervention through rapid review of WES results. Conclusions: WES could increase the detection rate of abnormal fetuses with negative G-banding karyotype analysis and CMA by 13.3%. Prenatal WES could guide pregnancy decision-making and early clinical intervention. It might be an effective strategy to pay attention to the special follow-up of the third trimester and postnatal fetus and to re-analyze the WES data.

Discriminating two races of Liobagrus marginatoides by cytogenetic analysis.

Although two kinds of Liobagrus marginatoides should belong to the same species according to the taxonomy of fish morphology, the results of cytogenetic analysis showed they are two different races.

AXIN2 gene silencing reduces apoptosis through regulating mitochondria-associated apoptosis signaling pathway and enhances proliferation of ESCs by modulating Wnt/ß-catenin signaling pathway.

OBJECTIVE: Embryonic stem cells (ESCs) mainly originate from totipotent cells in early-stage of mammalian embryo and could proliferate in a manner of un-limitation. This study aimed to investigate roles of Axin2 in proliferation of ESCs and explore the associated mechanisms. MATERIALS AND METHODS: Axis inhibition protein 2 (AXIN2) over-expression (LV5-AXIN2) and AXIN2 RNA interfere (LV3-AXIN2-RNAi) vectors were structured and transfected into H9 cells. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) was used to evaluate cell proliferative activity. Flow cytometry analysis was employed to measure apoptosis of H9 cells. AXIN2, ß-catenin, transcription factor 4 (TCF4), c-myc, c-jun and Cyclin D mRNA levels and protein expressions were determined using quantitative real-time PCR (qRT-PCR) and Western blotting assay. RESULTS: LV5-AXIN2 and LV3-AXIN2-RNAi were successfully structured with higher transfecting efficacy. AXIN2 gene silencing remarkably increased proliferative activity and AXIN2 treatment significantly induced apoptosis of H9 cells, comparing with blank vector group (p<0.05). AXIN2 gene silencing significantly enhanced B-cell lymphoma-2 (Bcl-2) expression and remarkably inhibited cleaved caspase-3 expression comparing to that in blank vector group (p<0.05). AXIN2-RNAi treatment significantly enhanced and AXIN2 over-expression significantly reduced ß-catenin and TCF4 expression, comparing to that in blank vector group (p<0.05). AXIN2 gene silence activated down-stream molecules of Wnt/ß-catenin signaling pathway, including c-jun, c-myc, and Cyclin D1 (p<0.05). CONCLUSIONS: AXIN2 gene silencing reduced apoptosis by regulating mitochondria-associated apoptosis signaling pathway and enhanced proliferation by modulating molecules in Wnt/ß-catenin signaling pathway. Therefore, targeting of aberrant apoptosis and AXIN2 might be a novel clinical strategy to inhibit aging and enhance self-renewal of ESCs.

The 5S rDNA related repetitive sequences in the sex chromosomes of the spiny eel (Mastacembelus aculeatus).

The karyotype of the spiny eel (Mastacembelus aculeatus) has highly evolved heteromorphic sex chromosomes. X and Y chromosomes differ from each other in the distribution of heterochromatin blocks. To characterize the repetitive sequences in these heterochromatic regions, we microdissected the X chromosome, constructed an X chromosome library, amplified the genomic DNA using PCR and isolated a repetitive sequence DNA family by screening the library. All family members were clusters of two simple repetitive monomers, MaSRS1 and MaSRS2. We detected a conserved 5S rDNA gene sequence within monomer MaSRS2; thus, tandem-arranged MaSRS1s and MaSRS2s may co-compose 5S rDNA multigenes and NTSs in M. aculeatus. FISH analysis revealed that MaSRS1 and MaSRS2were the main components of the heterochromatic regions of the X and Y chromosomes. This finding contributes additional data about differentiation of heteromorphic sex chromosomes in lower vertebrates.

Cerebellar interpositus nucleus modulates neuronal activity of lateral hypothalamic area.

Effects of stimulating the cerebellar interpositus nucleus (IN) on the neuronal activity of lateral hypothalamic area (LHA) were first observed in the cat. The results showed that (1) IN stimulation could elicit inhibitory, excitatory, inhibitory-excitatory and excitatory-inhibitory responses from LHA neurones, with a majority of inhibitory responses (46.9%); (2) the responsive latencies of LHA neurones to IN stimulation ranged from 5 to 45 ms, while most (83.6%) showed a short latency of < 15 ms; (3) of 67 LHA neurones which responded to the IN stimulation, 42 (62.7%) cells were identified to be glucose-sensitive neurones. These results suggest that IN may be involved in the role of LHA modulating food intake behaviour, as well as other non-somatic functions.

Electrophysiological study of the corticonuclear projection in the cat cerebellum.

Experiments were designed to examine the relationship between the responses of Purkinje cells to natural peripheral stimuli and the location of these neurons within identified zones of the corticonuclear projection in lobule V of the cat cerebellar cortex. It was hypothesized that the corticonuclear zones are sharply demarcated and that the responses of Purkinje cells to a restricted natural stimulus is not localized to only one zone but rather is present and varies in character across these 3 zones. Initially the spatial distribution of the antidromic field potential evoked by stimulating in the fastigial (FN), lateral vestibular (LVN), and anterior interposed nuclei (AIN) was determined in sublobules Va-Vc in unanesthetized decerebrate cats. In some animals the corticonuclear projection was further examined by evaluating the location of Purkinje cells responding antidromically to stimuli in the FN, LVN and AIN, or FN, AIN and the posterior interposed nuclei (PIN). Once a Purkinje cell was identified, its simple and complex spike responses to a step-like flexion-extension passive movement of the ipsilateral forepaw were determined. The boundary based on the antidromic activation of Purkinje cells between the fastigial zone (FZ) and the anterior interposed zone (AIZ) in sublobules Va-Vc of the cerebellar cortex was highly reproducible from cat to cat, although there was a slight overlap between these zones based on the antidromic field potential. The FZ-AIZ border was located at 2.1 +/- 0.12 mm lateral and parallel to the midline. The FZ also contained a few cells projecting to the LVN. However, the AIZ only contained neurons projecting to the AIN. The boundary between AIZ and PIZ in lobule Va-Vc was between 3.3 and 3.8 mm from the midline and ran parallel to it. The peristimulus time histograms (PSTHs) of the simple and complex spike activity to a passive forepaw displacement revealed extensive modulation of neurons located across the mediolateral extent of the AI and PIZ. Both the simple and complex spike discharge of Purkinje cells projecting to the FN also were modulated, but to a lesser degree than cells in AIZ or PIZ. The spatial distribution of simple and complex spike responses recorded from Purkinje cells overlapped extensively. The data support previous findings that the corticonuclear projection is organized into longitudinally oriented sagittal zones. Electrophysiologically the boundaries were remarkably reproducible from animal to animal. The results also show that information processing involving the modulation of Purkinje cell activity in response to the forepaw stimulus occurs in all 3 zones examined.(ABSTRACT TRUNCATED AT 400 WORDS)

[Electron microscopic observation of synaptonemal complexes in spermatocytes of six species of fishes].

The synaptonemal complexes (SCs) in spermatocytes of six species of fishes were detected with a combination of surface spreading and silver staining technique and observed under both light and electron microscopes. These fishes are Tilapia nilotica, T. mossambica and Mastacembelus sinensis of Perciformes. Sarcocheilichthys nigripinnis, Pseudorasbora parva and Hemibarbus maculatus of Gobioninae in Cypriniformes. The formation of SCs started in Zygotene and completed at Pachytene. During the pachytene, each SC was morphologically intact, preferentially stained and attached to the nuclear envelope by a dense terminal plaque. Interlock in SCs frequently occurred in Zygotene. In several cases breakage and disentangling of interlocked lateral elements were observed. SCs disappeared in diplotene. The pairing of the SCs started at telomeres and stretched towards kinetochore. The sex determination of Mastacembelus sinensis was xx/xy. The X and Y chromosomal SCs' axes had a distinctive morphology at pachytene and were clearly distinguishable from autosomal SCs. The X and Y chromosomes begain to pair at early pachytene. The X and Y chromosome axes paired to form a length of SC that is somewhat longer than the unpaired portion at the mid-pachytene. There was a dense substance at unpaired portion. Quantitatine evaluation demonstrated that relative length and arm ratio were distinctive characteristics for each autosomal SC. The consistency of relative length and arm ratio indicates the stability of the techniques. The idiograms of SC karyotypes of three species (Tilapia niloticus, T. mossambicus and Mastacembelus sinensis) have been constructed.

[The conservative region sequence analysis of PdSox9 in Paramisgurnus dabryanus].

Degenerate primers within HMG-box analyzed the Sox genes of P. dabryanus. Three amplification bands with the length 220, 550 and 1500 bp respectively were observed. A novel gene was obtained from the 550 bp band. The identity of possible amino acid sequence to Sox9 of human, mouse and chicken is 94%. The similarity to HSOX10, MSox10, HSRY, MSry is 87%, 55%, 40% and 47% respectively. So, it was named PdSox9. Northern blotting result showed that it overexposes in adult testis and brain.

[The chromosome mapping of PdSox8 and PdSox9 in two kinds of loaches].

With the Dig-labelled PdSox8 and PdSox9 as probes, the chromosome mapping of Sox8 and Sox9 in Paramisgurnus dabryanus and Misgurnus anguillicaudatus were analyzed by chromosome in situ hybridization technique. In P. dabryanus, the PdSox8 and PdSox9 were successfully localized in the No. 4 and No. 2 telocentric chromosome respectively, the relative distance to centromere is 40.2% and 67.5%; In M. anguillicaudatus, they were localized in the No. 9 and No. 6 telocentric chromosome respectively, the relative distance to centromere is 58.3% and 30.8%.

[Painting the chromosomes of fishes with human sex chromosome-specific DNA probes].

Chromosome painting is one of the effective methods in studying the evolution of genomes. The chromosomes of the species of fishes--M. aculeatus, M. albus and D. rerio were painted respectively with human X and Y chromosome-specific DNA probes. The results showed that some homologous segments of human X chromosome were found in the genomes of all the three kind of fishes, all the segments were scattered on several pairs of homologous chromosomes in each kind of fish. But no homologous segment of the human Y chromosome was found.

[Px gene of rice-field eels primed in situ labeling].

Peroxidase (Px) gene of rice-field eels (Monopterus albus) was successfully localized to the segments of two bivalents, 8q15-q26 and 11q32-q37 with digoxigenin labeled primed in situ labeling (PRINS) technique, which is utilized for localization of single copy gene of fish for the first time. Our results demonstrated the possibility of mapping genes in fish by the DNA probes of other species and PRINS technique.

[Pattern recognition on the trace element spectrum in gastric cancer and peptic ulcer].

The trace element spectrum of gastric tissue and whole blood specimens from gastric cancer and peptic ulcer patients was recognized with pattern recognition technique in order to obtain the chemical information of gastric cancer. Thirty specimens were obtained from cancer patients in each of the 58 gastric tissues and 54 whole blood specimens. Five pathological types were divided into two groups: peptic ulcer and dysplasia as the ulcer group; well-differentiated, undifferentiated and mucinous carcinoma as the cancer group. The accuracy of recognizing the several spectra was 90%: nine trace element spectra (Cu, Zn, Ni, Co, Cr, Cd, Mn, Fe and Mg) for the tissue specimens from the cancer and ulcer groups; six (Cu, Zn, Mn, Co, Cr and Cd) for dysplasia and well-differentiated adenocarcinoma tissues; five (Cu, Ni, Cr, Cd and Fe) for the whole blood specimens from these two groups and six (Cu, Zn, Cr, Cd, Fe and Ni) for the whole blood specimens from dysplasia and peptic ulcer (including 10 normal individuals). The data were treated by non-linear mapping method and calculated by TRS-80 III type microcomputer.

[Hippocampus-cerebellar cortex-cerebellar nuclei projection in the rat: electrophysiological and HRP studies].

The spatial distribution of the hippocampus-cerebellar projection and the connection between the projection area of hippocampus in the cerebellum and cerebellar nuclei were studied by means of electrophysiological and HRP labelling techniques. Polysynaptic responses of Purkinje cell's simple and complex spike in the lobule VI could be evoked by stimulation of the area CA1/CA3 of the dorsal hippocampus. These results suggest that there are polysynaptic projections from CA1 and CA3 areas of dorsal hippocampus to the lobule VI of cerebellar cortex, and the last relay fibers for these projections are mossy fiber and/or climbing fiber. It is also shown that this hippocampus-cerebellar projection predominantly terminates at the lobule VI of cerebellar cortex, 0.8-1.4 mm lateral to the midline. The projection from CA1 area is mainly contralateral, whereas the projection from CA3 area is mainly ipsilateral. The results with HRP labelling indicate that the projection area of hippocampus is an interpositus zone of the lobule VI. Reciprocal connections may exist between this cortical area and the interpositus nucleus.

[Electrophysiological study of the corticonuclear projection in the lobule VII of cat cerebellum].

Antidromic field potentials and antidromic unit responses of Purkinje cells (PCs) to the stimulation of fastigial nucleus (FN), interposed nucleus (IN) and dentate nucleus (DN) were respectively recorded from the lobule VII of posterior cortex of decerebrated cats, to identify the corticonuclear projection in the lobule VII. After antidromically identified, simple and complex spike responses of PCs to natural peripheral forepaw extension-flexion stimuli were observed. All data were analysed by a computer, and average field potentials and poststimulus time histograms (PSTHs) were constructed. The results show that the corticonuclear zones are sharply demarcated on the lobule VII of posterior cortex. The boundary between the fastigial zone (FZ) and the interposed zone (IZ) on the lobule VII is not straight, but bends. Among sublobule VII Aa-VII Ad the FZ-IZ boundary bends from 2.8 mm to 1.5 mm laterally to the midline. The boundary between IZ and dentata zone (DZ) was about 5.0 mm away from the midline. The PSTHs of the simple and complex spike activities showed that part of PCs in all three different corticonuclear zones responded to the forepaw flexion-extension stimulation, but proportion of the cells affected was quite different among the three zones. In the IZ 84% PCs were modulated by the forepaw stimulation, while in the FZ and DZ it was 59% and 20% respectively. These results support previous finding that information processing involved in the modulation of Purkinje cell activity in response to the forepaw stimulation occurs in all 3 zones examined.

[Effects of dorsal raphe stimulation on activities of cerebellar nuclear neurons in the rat].

The effects of stimulating dorsal raphe nucleus (DR) on activities of three deep cerebellar nuclei (DCN) (medial, interposed and lateral nuclei) were investigated. The results were as follows: (1) Stimulation of DR elicited three types of responses, inhibition, excitation, and biphasic response (excitation-inhibition or inhibition-excitation) from DCN cells with responsive latencies ranging from 10 to 84 ms. The majority of responsive cells showed an inhibitory response (76%-90%) with a latency less than 30 ms. (2) The spontaneous discharge frequencies of the DCN cells were 5 to 120 Hz. The cells with higher spontaneous discharge frequencies showed low responsive rates to the DR stimulation, as compared with lower firing frequency cells. (3) The depressive effect of DR stimulation could be blocked by injection of 5-HT2/1c antagonist methysergide (66.7%-83.3%). These results suggest that raphe-cerbellum serotonergic afferent fibers may be involved in the cerebellar sensorimotor integration process by exerting some modulatory effects on the DCN cell's activities.

[Stimulation of the dorsal raphe nucleus induced depressive effect on cerebellar Purkinje cell responses to mossy and climbing fiber afferent inputs in rat].

In anaesthetized and paralyzed rats, the effect of dorsal raphe (DR) conditioning stimulation on cerebellar Purkinje cell (PC) responses to mossy fiber and climbing fiber inputs were examined. The main results are as follows: (1) Stimulation of cerebral sensorimotor cortex elicits widespread activation of mossy and climbing fiber inputs to PCs in contralateral VI and VII lobules of the cerebellum and generates two kinds of evoked responses, i.e. the simple spike (SS) and the complex spike (CS) responses with respectively a latency 8-25 and 12-30 ms. (2) These PC responses could be markedly suppressed by stimulation of DR at intensities which by themselves were subthreshold for directly affecting PC's spontaneous SS and CS activities. (3) This DR-induced depressive effects on evoked PC's SS and CS excitations could be attenuated or blocked by systemic administration of 5-HT receptor blocker methysergide. These results demonstrate that serotonergic fiber input from DR can suppress the efficacy of mossy and climbing fiber synaptic action on PC, or decrease the responsiveness of PC itself to afferent synaptic action. The findings of this study also suggest that the raphe-cerebellar serotonergic fiber afferent system may be involved in some of the important neuronal processing in the cerebellum.

[Effects of stimulating lateral hypothalamic area and ventromedial nucleus of hypothalamus on cerebellar cortical neuronal activity in the cat].

In pentobarbital anaesthetized cat, stimulating lateral hypothalamic area (LHA) and ventromedial nucleus (VMN) of the hypothalamus could elicit inhibitory, excitatory or inhibitory-excitatory responses of cerebellar Purkinje cells (PC) and non-Purkinje cells (NPC) in the loubles VI and VII. The majority of responses are inhibitory (80.4%) usually with a latency of 10-20 ms, or occassionaly as long as 90 ms. Usually stimulation of LHA was more effective and NPC was more responsive. The aforementioned inhibitory response could be blocked by iv. chlorpheniramine. The possible role of the hypothalamo-cerebellar activity was discussed.

[Effects of NA and 5-HT on the spontaneous and evoked activities of Purkinje cells in cerebellar slice].

Effects of NA and 5-HT perfusion on the spontaneous activity and evoked responses of the Purkinje cells (PCs) to stimulation of white matter were studied in the rat cerebellar slices. The results were as follows: (1) Perfusion with NA could elicit inhibitory, excitatory or biphasic responses of the spontaneously discharging PCs, with inhibitory response in dominance (79.8%). 5-HT perfusion could also exert either excitatory or inhibitory effect on PC spontaneous activity. (2) When NA and 5-HT were perfused successively, NA tended to inhibit while 5-HT tended to excite in 53.8% of the tested cells. (3) Most of the complex spike (CS) and simple spike (SS) responses evoked by white matter stimulation could be potentiated by NA (68.2%, 57.1%) or depressed by 5-HT (60.0%, 68.2%). (4) On the same cell under successively perfusion with NA and 5-HT, the evoked CS and SS responses of most cells (60.0%, 52.9%) showed a tendency to be facilitated by NA and suppressed by 5-HT. These results suggest that aminergic afferent fibers, by releasing NA and 5-HT, may affect PC's excitability and responsiveness to synaptic inputs from mossy and climbing fibers, thus playing an important role in the cerebellar function.