Evidence for Chiral Wobbler in Nuclei

Three ΔI=1 bands with the πg_{9/2}⊗νg_{9/2} configuration have been identified in _{35}^{74}Br_{39}. Angular distribution, linear polarization, and lifetime measurements were performed to determine the multipolarity, type, mixing ratio, and absolute transition probability of the transitions. By comparing these experimental observations with the corresponding fingerprints and the quantum particle rotor model calculations, the second and third lowest bands are, respectively, suggested as the chiral partner and one-phonon wobbling excitation built on the yrast band. The evidence indicates the first chiral wobbler in nuclei.

Viral vector-mediated transgene delivery with novel recombinase systems for targeting neuronal populations defined by multiple features

A comprehensive understanding of neuronal diversity and connectivity is essential for understanding the anatomical and cellular mechanisms that underlie functional contributions. With the advent of single-cell analysis, growing information regarding molecular profiles leads to the identification of more heterogeneous cell types. Therefore, the need for additional orthogonal recombinase systems is increasingly apparent, as heterogeneous tissues can be further partitioned into increasing numbers of specific cell types defined by multiple features. Critically, new recombinase systems should work together with pre-existing systems without cross-reactivity in vivo. Here, we introduce novel site-specific recombinase systems based on ΦC31 bacteriophage recombinase for labeling multiple cell types simultaneously and a novel viral strategy for versatile and robust intersectional expression of any transgene. Together, our system will help researchers specifically target different cell types with multiple features in the same animal.

Optogenetic Stimulation Reduces Neuronal Nitric Oxide Synthase Expression After Stroke

Post-stroke optogenetic stimulation has been shown to enhance neurovascular coupling and functional recovery. Neuronal nitric oxide synthase (nNOS) has been implicated as a key regulator of the neurovascular response in acute stroke; however, its role in subacute recovery remains unclear. We investigated the expression of nNOS in stroke mice undergoing optogenetic stimulation of the contralesional lateral cerebellar nucleus (cLCN). We also examined the effects of nNOS inhibition on functional recovery using a pharmacological inhibitor targeting nNOS. Optogenetically stimulated stroke mice demonstrated significant improvement on the horizontal rotating beam task at post-stroke days 10 and 14. nNOS mRNA and protein expression was significantly and selectively decreased in the contralesional primary motor cortex (cM1) of cLCN-stimulated mice. The nNOS expression in cM1 was negatively correlated with improved recovery. nNOS inhibitor (ARL 17477)-treated stroke mice exhibited a significant functional improvement in speed at post-stroke day 10, when compared to stroke mice receiving vehicle (saline) only. Our results show that optogenetic stimulation of cLCN and systemic nNOS inhibition both produce functional benefits after stroke, and suggest that nNOS may play a maladaptive role in post-stroke recovery.

Coexistence of Reflection Asymmetric and Symmetric Shapes in ^{144}Ba

Level structures in the neutron-rich ^{144}Ba nucleus have been reinvestigated by measuring prompt γ rays in the spontaneous fission of ^{252}Cf. The previous s=+1 octupole band structure with reflection asymmetric shape has been expanded, and a side quadrupole band structure based on a 3^{+} state with reflection symmetric shape is identified. Thus, the results show the coexistence of reflection asymmetric and symmetric shapes in ^{144}Ba. This is a first identification of such a shape coexistence structure in a nuclear structure. The other structural characteristics are discussed.

Consensus Paper: Experimental Neurostimulation of the Cerebellum

The cerebellum is best known for its role in controlling motor behaviors. However, recent work supports the view that it also influences non-motor behaviors. The contribution of the cerebellum towards different brain functions is underscored by its involvement in a diverse and increasing number of neurological and neuropsychiatric conditions including ataxia, dystonia, essential tremor, Parkinson's disease (PD), epilepsy, stroke, multiple sclerosis, autism spectrum disorders, dyslexia, attention deficit hyperactivity disorder (ADHD), and schizophrenia. Although there are no cures for these conditions, cerebellar stimulation is quickly gaining attention for symptomatic alleviation, as cerebellar circuitry has arisen as a promising target for invasive and non-invasive neuromodulation. This consensus paper brings together experts from the fields of neurophysiology, neurology, and neurosurgery to discuss recent efforts in using the cerebellum as a therapeutic intervention. We report on the most advanced techniques for manipulating cerebellar circuits in humans and animal models and define key hurdles and questions for moving forward.

RNA-Sequencing Analysis Revealed a Distinct Motor Cortex Transcriptome in Spontaneously Recovered Mice After Stroke

Background and Purpose- Many restorative therapies have been used to study brain repair after stroke. These therapeutic-induced changes have revealed important insights on brain repair and recovery mechanisms; however, the intrinsic changes that occur in spontaneously recovery after stroke is less clear. The goal of this study is to elucidate the intrinsic changes in spontaneous recovery after stroke, by directly investigating the transcriptome of primary motor cortex in mice that naturally recovered after stroke. Methods- Male C57BL/6J mice were subjected to transient middle cerebral artery occlusion. Functional recovery was evaluated using the horizontal rotating beam test. A novel in-depth lesion mapping analysis was used to evaluate infarct size and locations. Ipsilesional and contralesional primary motor cortices (iM1 and cM1) were processed for RNA-sequencing transcriptome analysis. Results- Cluster analysis of the stroke mice behavior performance revealed 2 distinct recovery groups: a spontaneously recovered and a nonrecovered group. Both groups showed similar lesion profile, despite their differential recovery outcome. RNA-sequencing transcriptome analysis revealed distinct biological pathways in the spontaneously recovered stroke mice, in both iM1 and cM1. Correlation analysis revealed that 38 genes in the iM1 were significantly correlated with improved recovery, whereas 74 genes were correlated in the cM1. In particular, ingenuity pathway analysis highlighted the involvement of cAMP signaling in the cM1, with selective reduction of Adora2a (adenosine receptor A2A), Drd2 (dopamine receptor D2), and Pde10a (phosphodiesterase 10A) expression in recovered mice. Interestingly, the expressions of these genes in cM1 were negatively correlated with behavioral recovery. Conclusions- Our RNA-sequencing data revealed a panel of recovery-related genes in the motor cortex of spontaneously recovered stroke mice and highlighted the involvement of contralesional cortex in spontaneous recovery, particularly Adora2a, Drd2, and Pde10a-mediated cAMP signaling pathway. Developing drugs targeting these candidates after stroke may provide beneficial recovery outcome.

RSPO3 is a prognostic biomarker and mediator of invasiveness in prostate cancer

Background

While prostate cancer can often manifest as an indolent disease, the development of locally-advanced or metastatic disease can cause significant morbidity or mortality. Elucidation of molecular mechanisms contributing to disease progression is crucial for more accurate prognostication and effective treatments. R-Spondin 3 (RSPO3) is a protein previously implicated in the progression of colorectal and lung cancers. However, a role for RSPO3 in prostate cancer prognosis and behaviour has not been explored.

Methods

We compare the relative levels of RSPO3 expression between normal prostate tissue and prostate cancer in two independent patient cohorts (Taylor and GSE70768—Cambridge). We also examine the association of biochemical relapse with RSPO3 levels in these cohorts. For elucidation of the biological effect of RSPO3, we use siRNA technology to reduce the levels of RSPO3 in established prostate cancer cell lines, and perform in vitro proliferation, invasion, western blotting for EMT markers and clonogenic survival assays for radiation resistance. Furthermore, we show consequences of RSPO3 knockdown in an established chick chorioallantoic membrane (CAM) assay model of metastasis.

Results

RSPO3 levels are lower in prostate cancer than normal prostate, with a tendency for further loss in metastatic disease. Patients with lower RSPO3 expression have lower rates of biochemical relapse-free survival. SiRNA-mediated loss of RSPO3 results in no change to clonogenic survival and a lower proliferative rate, but increased invasiveness in vitro with induction of epithelial–mesenchymal transition (EMT) markers. Consistent with these results, lower RSPO3 expression translates to greater metastatic capacity in the CAM assay. Together, our preclinical findings identify a role of RSPO3 downregulation in prostate cancer invasiveness, and provide a potential explanation for how RSPO3 functions as a positive prognostic marker in prostate cancer.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1878-3) contains supplementary material, which is available to authorized users.

Optogenetic neuronal stimulation of the lateral cerebellar nucleus promotes persistent functional recovery after stroke

Stroke induces network-wide changes in the brain, affecting the excitability in both nearby and remotely connected regions. Brain stimulation is a promising neurorestorative technique that has been shown to improve stroke recovery by altering neuronal activity of the target area. However, it is unclear whether the beneficial effect of stimulation is a result of neuronal or non-neuronal activation, as existing stimulation techniques nonspecifically activate/inhibit all cell types (neurons, glia, endothelial cells, oligodendrocytes) in the stimulated area. Furthermore, which brain circuit is efficacious for brain stimulation is unknown. Here we use the optogenetics approach to selectively stimulate neurons in the lateral cerebellar nucleus (LCN), a deep cerebellar nucleus that sends major excitatory output to multiple motor and sensory areas in the forebrain. Repeated LCN stimulations resulted in a robust and persistent recovery on the rotating beam test, even after cessation of stimulations for 2 weeks. Furthermore, western blot analysis demonstrated that LCN stimulations significantly increased the axonal growth protein GAP43 in the ipsilesional somatosensory cortex. Our results demonstrate that pan-neuronal stimulations of the LCN is sufficient to promote robust and persistent recovery after stroke, and thus is a promising target for brain stimulation.

Abstract WP119: Transcriptome Analysis of Motor Cortex Network Responses in Spontaneously Recovered Stroke Mice

Introduction: Spontaneous recovery after stroke occurs in both human and animals. However, the underlying molecular mechanisms driving spontaneous recovery are still unclear. This study investigates the molecular mechanisms driving spontaneous recovery after unilateral experimental stroke using RNA sequencing (RNAseq).

Methods: Ischemic stroke was induced in C57BL/6J adult male mice by transient MCAO. Neurological score, vertical pole, and rotating horizontal beam test were performed at baseline and post stroke days (PD) 4, 8, and 14. All mice were sacrificed at PD15 and processed for immunohistochemistry or Hi-seq. Infarcts were visualized by T2WI at PD2 using 7T MR scanner or histology at PD15. All stroke mice included in the study have comparable cortico-striatal infarcts and exhibit similar prestroke baseline performance and PD4 deficits. These mice were further categorized into spontaneously recovered and non-recovered groups based on their rotating beam performance during recovery.

Results: Out of 35 stroke mice with abovementioned similar conditions, 9 (26%) were categorized into spontaneously recovered group and 26 (74%) were categorized into non-recovered group. Hierarchical clustering analysis supported this categorization. At PD14, the spontaneously recovered group exhibited significant improvement in beam performance in distance traveled and speed (p<0.001). Using Ingenuity Pathway Analysis, the comparison of RNAseq transcriptome between ipsilesional and contralesional primary motor cortex (iM1 and cM1) in spontaneously recovered and non-recovered stroke mice revealed significant differential molecular pathways, including glutamate, calcium, and neurotrophin signaling pathways.

Conclusions: Our study demonstrates that stroke mice with similar cortico-striatal infarct size can exhibit significant differences in their behavioral recovery outcome. The transcriptome profile in iM1-cM1 network at 2 weeks post-stroke highlighted several molecular pathways that were significantly different between spontaneously recovered and non-recovered mice. Validation of key molecular candidates from the RNAseq data would provide insights into the molecular mechanisms mediating spontaneous recovery after stroke.

[Pathological diagnosis and differential diagnosis for primary pulmonary mucinous epithelial tumors]

The cell origin of primary pulmonary mucinous epithelial tumors includes goblet cells, tracheobronchial mucous glands, the mucous cell metaplasia of ciliated and Clara cells, etc.There are benign, low-grade malignant potential and malignant tumors in this category. The benign tumors encompass mucous gland adenoma and mucinous cystadenoma. Ciliated muconodular papillary tumors are thought to be of low grade malignant potential or uncertain malignant potential neoplasm, while colloid adenocarcinoma and mucinous adenocarcinoma are malignant tumors. Most of primary pulmonary mucinous epithelial tumors are rare even extremely rare lesions. Similar morphological changes exist in the different tumors. Differential diagnosis for these entities may be challenging in pathological diagnosis on biopsies, even surgical sections. The clinicopathologic characteristics should be carefully analyzed to ensure accurate pathologic diagnosis for primary pulmonary mucinous epithelial tumors.

Preliminary consideration of CFETR ITER-like case diagnostic system

Chinese Fusion Engineering Test Reactor (CFETR) is a new superconducting tokamak device being designed in China, which aims at bridging the gap between ITER and DEMO, where DEMO is a tokamak demonstration fusion reactor. Two diagnostic cases, ITER-like case and towards DEMO case, have been considered for CFETR early and later operating phases, respectively. In this paper, some preliminary consideration of ITER-like case will be presented. Based on ITER diagnostic system, three versions of increased complexity and coverage of the ITER-like case diagnostic system have been developed with different goals and functions. Version A aims only machine protection and basic control. Both of version B and version C are mainly for machine protection, basic and advanced control, but version C has an increased level of redundancy necessary for improved measurements capability. The performance of these versions and needed R&D work are outlined.

Evidence for Gamow-Teller Decay of ^{78}Ni Core from Beta-Delayed Neutron Emission Studies

The β-delayed neutron emission of ^{83,84}Ga isotopes was studied using the neutron time-of-flight technique. The measured neutron energy spectra showed emission from states at excitation energies high above the neutron separation energy and previously not observed in the β decay of midmass nuclei. The large decay strength deduced from the observed intense neutron emission is a signature of Gamow-Teller transformation. This observation was interpreted as evidence for allowed β decay to ^{78}Ni core-excited states in ^{83,84}Ge favored by shell effects. We developed shell model calculations in the proton fpg_{9/2} and neutron extended fpg_{9/2}+d_{5/2} valence space using realistic interactions that were used to understand measured β-decay lifetimes. We conclude that enhanced, concentrated β-decay strength for neutron-unbound states may be common for very neutron-rich nuclei. This leads to intense β-delayed high-energy neutron and strong multineutron emission probabilities that in turn affect astrophysical nucleosynthesis models.

Decays of the Three Top Contributors to the Reactor ν[over ¯]_{e} High-Energy Spectrum, ^{92}Rb, ^{96gs}Y, and ^{142}Cs, Studied with Total Absorption Spectroscopy

We report total absorption spectroscopy measurements of ^{92}Rb, ^{96gs}Y, and ^{142}Cs β decays, which are the most important contributors to the high energy ν[over ¯]_{e} spectral shape in nuclear reactors. These three β decays contribute 43% of the ν[over ¯]_{e} flux near 5.5 MeV emitted by nuclear reactors. This ν[over ¯]_{e} energy is particularly interesting due to spectral features recently observed in several experiments including the Daya Bay, Double Chooz, and RENO Collaborations. Measurements were conducted at Oak Ridge National Laboratory by means of proton-induced fission of ^{238}U with on-line mass separation of fission fragments and the Modular Total Absorption Spectrometer. We observe a β-decay pattern that is similar to recent measurements of ^{92}Rb, with a ground-state to ground-state β feeding of 91(3)%. We verify the ^{96gs}Y ground-state to ground-state β feeding of 95.5(20)%. Our measurements substantially modify the β-decay feedings of ^{142}Cs, reducing the β feeding to ^{142}Ba states below 2 MeV by 32% when compared with the latest evaluations. Our results increase the discrepancy between the observed and the expected reactor ν[over ¯]_{e} flux between 5 and 7 MeV, the maximum excess increases from ∼10% to ∼12%.

Abstract WP106: Optogenetic Neuronal Stimulation Reduces Neuronal Nitric Oxide Synthase After Stroke

Objective: Nitric oxide (NO) is a gaseous messenger that mediates many physiological functions, including neuronal excitability, vascular tone and angiogenesis. Nitric oxide synthases are a family of enzymes that catalyzes the production of NO. While activation of endothelial NOS (eNOS) has been shown to be neuroprotective, activation of neuronal NOS (nNOS) and inducible NOS (iNOS) worsens ischemic damage. Although the role of NOS in acute stroke is well-established, their contribution in stroke recovery is less clear. Our lab recently demonstrated that optogenetic neuronal stimulation can enhance post-stroke recovery. As NOS mediates many physiological processes important for stroke recovery, we investigate whether NOS is involved in stimulation-enhanced recovery. We hypothesize that neuronal stimulations promote recovery by altering NOS expression.

Methods: Thy-1-ChR2-YFP line-18 transgenic male mice were used. Mice underwent experimental stroke induced by an intraluminal middle cerebral artery suture occlusion. Repeated optogenetic stimulations in the contralesional cerebellar dentate nucleus (cLCN) were administered from post-stroke day5-14. Functional recovery was evaluated by sensory-motor behavior tests. Mice were sacrificed at post-stroke day15, ipsilesional and contralesional motor and sensory cortices were dissected. qPCR was performed to examine expression of nNOS, iNOS and eNOS.

Results: Our data showed that stimulated stroke mice recovered quickly, with significantly faster rotating beam speed at day14 post-stroke (p<0.001). Quantitative PCR revealed that stimulations significantly reduced nNOS expression, while no change was detected for eNOS and iNOS. Interestingly, nNOS was significantly reduced in the contralesional primary motor cortex in cLCN-stimulated stroke mice (p<0.001), suggesting the involvement of nNOS in the contralesional cortex in stroke recovery.

Conclusion: Optogenetic stimulations promote post-stroke recovery and selectively reduced nNOS expression in the contralesional motor cortex. Current ongoing studies examine the nNOS signaling pathway after stimulation and the effect of manipulating nNOS expression in stroke recovery.

Abstract T MP19: Optogenetic Stimulation of Cerebellar Dentate Nucleus Promotes Persistent Functional Recovery After Stroke

Objective: Functional recovery after stroke has been observed in both human and animal studies. Post-stroke brain stimulations are promising neurorestorative techniques as they allow direct manipulation of the target area’s excitability. Previously we have demonstrated that optogenetic neuronal stimulation of the ipsilesional primary motor cortex promotes functional recovery. To determine an optimal brain stimulation target, we test whether optogenetic neuronal stimulation of the contralesional cerebellar dentate nucleus (cLCN) can promote recovery. We hypothesize that stimulation of cLCN may be more effective, as it sends excitatory outputs to multiple motor and premotor areas.

Methods: Thy-1-ChR2-YFP line-18 transgenic male mice were used. Mice underwent stereotaxic surgery to implant a fiber cannula in cLCN, followed by an intraluminal middle cerebral artery suture occlusion. Three groups of mice were used: control non-stimulated stroke mice, short stim stimulated stroke mice (day5-14 post-stroke) and long stim stimulated stroke mice (day5-28 post-stroke). Sensorimotor behavior tests (rotating beam tests) were used to assess their recovery at day 0, 4, 7, 10, 14, 21 and 28 post-stroke.

Results: Our data showed that stimulated stroke mice recovered quickly, with significant improvement in distance traveled as early as day7 (p<0.05), and faster speed at day14 post-stroke (p<0.001). To evaluate whether the effect of cLCN stimulation was persistent, we tested the effects of short stim (day5-14) and long stim (day5-28) on recovery. Interestingly, the short stim group continued to recover after day14 without further stimulations and the long stim group did not further enhance recovery, indicating that functional outcome of cLCN stimulation is persistent, and prolonged stimulations may not be necessary to achieve permanent recovery. Analysis of pCREB activation showed that cLCN stimulation activates the dentatothalamocortical pathway.

Conclusion: Our data suggest that cLCN stimulations post-stroke can promote functional recovery, and this pro-recovery effect is persistent. Current studies examine the mechanisms of cLCN-induced recovery, including cortical excitability and synaptic/plasticity markers.

Optogenetic approaches to study stroke recovery

Treatment for stroke is very limited, and potential new therapies are focusing on promoting brain repair and plasticity, as they offer a longer therapeutic time window than the current U.S. Food and Drug Administration approved drug. Functional recovery can occur after stroke, and strategies such as direct brain stimulations that promote recovery are promising. Here we review how selective stimulation of neurons in the motor cortex using optogenetics enhances plasticity mechanisms and promotes functional recovery after stroke.

Abstract W P96: Optogenetic Neuronal Stimulation Enhances Neurotrophin Expression in the Contralesional Motor Cortex After Stroke

Objective: Functional recovery after stroke has been observed and is currently attributed to both brain remodeling and plasticity. One form of cortical reorganization involves the balance of interhemispheric interactions between ipsilesional and contralesional cortex. Stimulation of ipsilesional primary motor cortex (iM1) has been shown to be beneficial, however, the role of the contralesional M1 (cM1) remains controversial. Recently we showed that optogenetic stimulations of iM1 post-stroke promote functional recovery. In this study, we investigate the role of contralesional cortex in recovery by optogenetically stimulating iM1 or cM1 and examine the involvement of activity-dependent neurotrophins.

Methods: Thy-1-ChR2-YFP line-18 transgenic male mice were used. Mice underwent stereotaxic surgery to implant a fiber cannula in either iM1 or cM1, followed by an intraluminal middle cerebral artery suture occlusion. Optogenetic stimulation began at day5 post-stroke and continued until day14 post-stroke. Sensorimotor behavior tests were used to assess their recovery at day 0, 2, 7, 10 and 14 post-stroke. Mice were sacrificed at day15 post-stroke and neurotrophin expressions were examined using quantitative PCR.

Results: Repeated iM1 stimulations promoted functional recovery at day14 post-stroke, with improved motor performance on the rotating beam test (p<0.01). Real-time PCR revealed significant increases of neurotrophin expressions in contralesional M1 at day15 post-stroke, including brain-derived neurotrophic factor (BDNF) (p<0.05), nerve growth factor (NGF) (p<0.05) and neurotrophin 3 (NTF3) (p<0.05). BDNF and NTF3 expression were also significantly increased in the contralesional S1 of stimulated mice (p<0.05).

Conclusion: Our data suggest that activity-dependent neurotrophins in the contralesional cortex may be an important mechanism mediating stroke recovery. Current studies include specific stimulation and inhibition of the iM1 or cM1 post-stroke to elucidate the neurocircuitry mediating stroke recovery. In addition, the expression of neurotrophins will be examined in these studies to elucidate their role in the recovery process.

RNAi-mediated knockdown of FANCF suppresses cell proliferation, migration, invasion, and drug resistance potential of breast cancer cells

Fanconi anemia complementation group F protein (FANCF) is a key factor, which maintains the function of FA/BRCA, a DNA damage response pathway. However, the functional role of FANCF in breast cancer has not been elucidated. We performed a specific FANCF-shRNA knockdown of endogenous FANCF in vitro. Cell viability was measured with a CCK-8 assay. DNA damage was assessed with an alkaline comet assay. Apoptosis, cell cycle, and drug accumulation were measured by flow cytometry. The expression levels of protein were determined by Western blot using specific antibodies. Based on these results, we used cell migration and invasion assays to demonstrate a crucial role for FANCF in those processes. FANCF shRNA effectively inhibited expression of FANCF. We found that proliferation of FANCF knockdown breast cancer cells (MCF-7 and MDA-MB-435S) was significantly inhibited, with cell cycle arrest in the S phase, induction of apoptosis, and DNA fragmentation. Inhibition of FANCF also resulted in decreased cell migration and invasion. In addition, FANCF knockdown enhanced sensitivity to doxorubicin in breast cancer cells. These results suggest that FANCF may be a potential target for molecular, therapeutic intervention in breast cancer.

Abstract TP105: Increaed GABA A Mediated Synaptic Activity and Structural Remodeling in Peri-infarct Cortex Layer 5 in the Post-stroke Rodent Brain

Introduction: The mechanisms of functional recovery after stroke are thought to be based on structural and functional changes in brain circuits adjacent to or connected with the stroke site. Deciphering these changes at the synaptic level is key to understanding the re-organization of the synaptic circuitry. Here we use a combined approach of i) array tomography to determine the composition of GABA synapses in the post-stroke mouse brain, with ii) electrophysiology to determine whether stroke leads to functional changes in GABA A receptor-mediated neurotransmission.

Methods: A cortical lesion was induced in 12-week-old C57BL/6J male mice using the distal middle cerebral artery occlusion model of ischemia. For array tomography, small tissue was removed from the peri-infarct cortex and ribbons of serial ultrathin sections were obtained. Ribbons were stained with antibodies for synaptic markers. Analysis of the resultant staining pattern was used to quantify GABAergic synapses. In addition, whole-cell patch clamp recordings from acute neocortical brain slices were performed to evaluate GABA-mediated synaptic signaling in the peri-infarct cortex. Behavior was evaluated weekly.

Results: At 1 week post-stroke, the array tomography data revealed an increase in the density and proportion of alpha1 subunit-containing GABAergic synapses in layer 5 of the peri-infarct cortex (Density: 0.064 vs 0.036 synapses/μm3. Proportion: 15.3 vs 9.1 %, p<0.05, n=6); no changes were observed in layer2/3. Changes in GABA synapses were transient and returned to basal levels by 1 month. Electrophysiological recordings at 1 week post-stroke showed that GABA A receptor-mediated currents were enhanced in layer 5, but not in layer 2/3. These changes were specific to the pyramidal neurons. Behavioral impairment after stroke was observed only at 1 week compared to sham mice (p<0.05, n=10).

Conclusion: Our results suggest that stroke leads to an increased expression of functional GABA A receptors in peri-infarct neocortex and that these changes are layer- and cell type-specific. These synaptic changes may represent a mechanism of post-stroke functional recovery and remapping of surviving circuits.

Abstract TMP35: Optogenetic Stimulation Of Motor Cortex Neurons Promotes Recovery After Stroke

Objective: Functional recovery after stroke has been observed in both animal and human studies and is currently attributed to both brain remodeling and plasticity. Brain stimulation techniques such as electrical stimulation and transcranial magnetic stimulation have been used successfully to enhance recovery. However, what mediates this recovery is not well understood. Elucidating the mechanism(s) is difficult because these stimulation techniques non-specifically activate all cell types near the stimulation site. Here we use optogenetic techniques to specifically stimulate layer V pyramidal neurons in the ipsilesional motor cortex at day 5 post-stroke, and investigate the effects on functional recovery as well as underlying mechanisms.

Methods: Thy-1-ChR2-YFP line-18 transgenic male mice were used. Mice underwent stereotaxic surgery to implant a fiber cannula in the ipsilesional M1. All mice were then subjected to an intraluminal middle cerebral artery suture occlusion (30min). Optogenetic stimulation began at day 5 post-stroke and continued until day 14 post-stroke. Sensorimotor behavior tests were used to assess their behavioral recovery at day 0, 2, 7, 10 and 14 post-stroke. Body weights were also measured. Changes in cerebral blood flow were measured at day 14 post-stroke using the Laser Doppler Flowmetry.

Results: Rotating beam test revealed that stimulated mice recovered significantly faster than non-stimulated control mice at day 10 and 14 after stroke (p<0.05). Stimulated mice also performed significantly better in the adhesive tape test at day 14, with a shorter tape removal time on the contralesional limb (p<0.05). Additionally, a significantly faster regain of body weight was observed in stimulated mice after stroke (p<0.05-0.01). Cerebral blood flow measurements revealed that stimulated mice exhibited significantly larger increase in cerebral blood flow at day 14 post-stroke (p<0.05-0.01).

Conclusion: These data indicate that optogenetic stimulation of motor cortex neurons can promote behavioral recovery in mice after stroke. Current studies examine the mechanisms underlying this recovery, including genes related to neurovascular coupling and neurotrophic factors after stimulation.

Down-regulation of TSG101 by small interfering RNA inhibits the proliferation of breast cancer cells through the MAPK/ERK signal pathway

We designed to investigate the effects of down-regulating the tumor susceptibility gene 101 (TSG101) on the proliferation and apoptosis of the human breast cancer MCF-7 cell line, and the role of the MAPK/ERK signal pathway in this process. The siRNA against TSG101 was transfected into the breast cancer MCF-7 cell line using Lipofectamine 2000. After TSG101 knockdown, the proliferation of MCF-7 cells was measured by the MTT assay. The cell cycle distribution and apoptosis were examined by using flow cytometry while cell migration was measured using a transwell assay. The protein level of p-ERK was further assessed by immunofluorescence and western blotting. Our results are as following, the MCF-7 cells transfected with TSG101 siRNA proliferated significantly slower and exhibited significantly increased rates of apoptosis compared to the control cells. In the TSG101 siRNA transfected cells, the percentage of cells in the G₀/G₁ and S phase of the cell cycle was significantly higher and lower, respectively, compared to the control cells. Moreover, the migration ability of TSG101 siRNA transfected cells was lower than the control groups. Lastly, the level of p-ERK protein in TSG101 siRNA transfected cells was significantly decreased compared with the control cells. In conclusion, TSG101 knockdown in breast cancer cells induces apoptosis and inhibits proliferation. The TSG101 depleted cells are arrested at the G₁/S transition of the cell cycle. The migration of breast cancer cells is also impaired by TSG101 siRNA. TSG101 may play a biological role through modulation of the MAPK/ERK signaling pathway in breast cancer.

High-dose CEB vs BEAM with autologous stem cell transplant in lymphoma

Between January 1996 and July 2002, 72 patients with non-Hodgkin's lymphoma or Hodgkin's disease underwent high-dose chemotherapy with autologous stem cell transplant conditioned with either cyclophosphamide, etoposide, carmustine (CEB) or carmustine, etoposide, cytarabine, melphalan (BEAM) at a single institution. In all, 52 patients received CEB and 20 patients received the BEAM regimen. Patient characteristics that were significantly different between the two groups are tumor grade and extranodal involvement (P = 0.0196, 0.0341, respectively). Regimen-related toxicities examined yielded only diarrhea occurring at a higher rate in the BEAM group (81 vs 51%, P = 0.0026), although cases were milder (92 vs 57%). Patients treated with CEB developed mucositis at a slightly higher rate (79%) than patients treated with BEAM (75%), but this difference did not reach statistical significance. However, the mucositis that occurred within the BEAM group was predominately mild (67%) in contrast to the predominance of moderate to severe cases in the CEB group (74%). In addition, patients treated with CEB required growth factor support for a longer time than patients treated with BEAM (P = 0.0399). Response rates were high in both groups, with trends favoring the BEAM group. Overall survival was higher after treatment with BEAM than with CEB (84 vs 60%).

Peptide mimetic HIV protease inhibitors are ligands for the orphan receptor SXR

The orphan nuclear receptor SXR coordinately regulates drug clearance in response to a wide variety of xenobiotic compounds. This signaling system protects the body from exposure to toxic compounds; however, it can also pose a severe barrier to drug therapy. We now demonstrate that the human immunodeficiency virus (HIV) protease inhibitor ritonavir binds SXR and activates its target genes. This represents an example of a commonly used therapeutic agent that effectively activates SXR. We also show that other protease inhibitors are weaker (saquinavir) or unable to activate SXR (nelfinavir, indinavir) thus defining analogs that fail to induce SXR-regulated clearance pathways. Interestingly, HIV protease inhibitors are distinct from previously known SXR ligands in that they are peptide mimetic compounds. This expands the ligand specificity of SXR to include this unique chemical class whose pharmaceutical significance is expanding. Finally, we show that SXR ligands activate expression of multiple resistance protein 2, a critical regulator of bile flow and biliary drug excretion. These findings have important implications for the role of SXR in regulating drug clearance and hepatic disorders associated with impaired bile flow.

Hepatitis B virus HBx protein activation of cyclin A-cyclin-dependent kinase 2 complexes and G1 transit via a Src kinase pathway

Numerous studies have demonstrated that the hepatitis B virus HBx protein stimulates signal transduction pathways and may bind to certain transcription factors, particularly the cyclic AMP response element binding protein, CREB. HBx has also been shown to promote early cell cycle progression, possibly by functionally replacing the TATA-binding protein-associated factor 250 (TAF(II)250), a transcriptional coactivator, and/or by stimulating cytoplasmic signal transduction pathways. To understand the basis for early cell cycle progression mediated by HBx, we characterized the molecular mechanism by which HBx promotes deregulation of the G0 and G1 cell cycle checkpoints in growth-arrested cells. We demonstrate that TAF(II)250 is absolutely required for HBx activation of the cyclin A promoter and for promotion of early cell cycle transit from G0 through G1. Thus, HBx does not functionally replace TAF(II)250 for transcriptional activity or for cell cycle progression, in contrast to a previous report. Instead, HBx is shown to activate the cyclin A promoter, induce cyclin A-cyclin-dependent kinase 2 complexes, and promote cycling of growth-arrested cells into G1 through a pathway involving activation of Src tyrosine kinases. HBx stimulation of Src kinases and cyclin gene expression was found to force growth-arrested cells to transit through G1 but to stall at the junction with S phase, which may be important for viral replication.

Requirement for TAF(II)250 acetyltransferase activity in cell cycle progression

The TATA-binding protein (TBP)-associated factor TAF(II)250 is the largest component of the basal transcription factor IID (TFIID). A missense mutation that maps to the acetyltransferase domain of TAF(II)250 induces the temperature-sensitive (ts) mutant hamster cell lines ts13 and tsBN462 to arrest in late G(1). At the nonpermissive temperature (39.5 degrees C), transcription from only a subset of protein encoding genes, including the G(1) cyclins, is dramatically reduced in the mutant cells. Here we demonstrate that the ability of the ts13 allele of TAF(II)250 to acetylate histones in vitro is temperature sensitive suggesting that this enzymatic activity is compromised at 39.5 degrees C in the mutant cells. Mutagenesis of a putative acetyl coenzyme A binding site produced a TAF(II)250 protein that displayed significantly reduced histone acetyltransferase activity but retained TBP and TAF(II)150 binding. Expression of this mutant in ts13 cells was unable to complement the cell cycle arrest or transcriptional defect observed at 39.5 degrees C. These data suggest that TAF(II)250 acetyltransferase activity is required for cell cycle progression and regulates the expression of essential proliferative control genes.

Deletion of chromosome 1 predicts prognosis in pancreatic endocrine tumors

Endocrine tumors, such as parathyroid adenomas and pheochromocytomas, frequently have deletions of chromosome 1, suggesting that inactivation of a tumor suppressor gene from chromosome 1 is important in their tumorigenesis. We hypothesized that deletion of chromosome 1 may contribute to pancreatic endocrine tumor formation. Twenty-nine sporadic and MEN1 pancreatic endocrine tumors were studied for loss of heterozygosity (LOH) with 12 chromosome 1 microsatellite markers. LOH on chromosome 1 was identified in 10 of 29 (34%) tumors studied. Allele loss occurred more frequently in tumors with hepatic metastases (7 of 8) than tumors without metastases (3 of 21) (P = 0.004). Tumors in patients with lymph node involvement and patients with multiple endocrine neoplasia type 1 did not demonstrate LOH for chromosome 1 markers. These data suggest that loss of chromosome 1 is associated specifically with the development of hepatic metastases in patients with sporadic pancreatic endocrine tumors.

Mutation of the MENIN gene in sporadic pancreatic endocrine tumors

Pancreatic endocrine tumors occur both sporadically and as part of the multiple endocrine neoplasia type 1 (MEN1) syndrome. MEN1 is an autosomal dominant disease characterized by parathyroid hyperplasia, pancreatic endocrine tumors, and pituitary adenomas. The MEN1 gene called MENIN maps to chromosome 11q13 and is thought to function as a tumor suppressor gene. We previously demonstrated loss of heterozygosity (LOH) at 11q13 in approximately 40% of sporadic pancreatic endocrine tumors and hypothesize that MENIN is involved in the development of these tumors. Thirty-one sporadic pancreatic endocrine tumors were analyzed for mutation of MENIN by nonradioactive single-stranded conformation polymorphism. Twelve mutations were detected in 31 sporadic pancreatic endocrine tumors (34%). Twelve of these 31 tumors previously demonstrated loss of heterozygosity at 11q13. Of the tumors with LOH, seven contained mutations of the MENIN gene (58%). The majority of the MENIN mutations occurred within exon 2. Two independent mutations in MENIN were detected in a gastrinoma that also revealed LOH, leading to the possibility of another tumor suppressor gene locus at 11q13. Mutations were present in both benign and malignant pancreatic endocrine tumors, suggesting that a MENIN gene mutation is a frequent and early event in the tumorigenesis. The high incidence of truncating mutations in tumors with LOH at 11q13 support the hypothesis that MENIN is a tumor suppressor gene.

TAFII250-dependent transcription of cyclin A is directed by ATF activator proteins

A specific mutation in TAFII250, the largest subunit of the transcription factor TFIID, disrupts cell growth control in the temperature-sensitive mutant hamster cell line ts13. Transcription from the cyclin A and D1 but not the c-fos and myc promoters is also dramatically reduced in ts13 cells at the nonpermissive temperature. These findings provide an intriguing link between TAF-mediated transcriptional regulation and cell cycle progression. Here we report the mapping of an enhancer element in the cyclin A promoter (TSRE) that responds to mutations in TAFII250. An analysis of chimeric promoter constructs reveals that the cyclin A TSRE can confer TAFII250 dependence to the core promoter of c-fos. In addition, reciprocal hybrid promoter constructs suggest that TAFII250 also contributes to the transcriptional properties of the cyclin A core promoter. We have purified and identified cellular activators that specifically bind to the TSRE and mediate transcription in a TAFII250-dependent manner. By micropeptide sequencing, we determined that TSRE-binding proteins include members of the activating transcription factor (ATF) family. These results suggest that the ts13 mutation of TAFII250 has compromised the ability of TFIID to mediate activation of transcription by specific enhancer factors such as ATF, as well as to perform certain core promoter functions. These defects in TAFII250 apparently result in the down-regulation of key molecules, such as cyclin A, which may be responsible for the ts13 cell cycle arrest phenotype.

[Synthesis and antibacterial activity of tricycic fluoroquinolones]

Twelve new analogues of new tricyclic rufloxacin were prepared and their MIC were evaluated against thirteen kinds of bacteria. As a result of these studies: the polarity of C10-side chain was found to exert greater positive effect on G- than on G+ bacteria.

Ruptured deep femoral artery aneurysm simulating a soft-tissue sarcoma: a case report

False aneurysms of the deep femoral artery are uncommon. The presentation in the 80-year-old woman described in this case report was unique in that the pseudoaneurysm was subacute; after an initial hemorrhage, compression of the pseudoaneurysm by the deep femoral artery resulted in a large hematoma suggestive of a soft-tissue sarcoma. The recommended management was angiography, computed tomography and magnetic resonance imaging to differentiate between a false aneurysm and a tumour followed by treatment for the vascular lesion. Such an approach will prevent tumour spread and uncontrollable hemorrhage.

Percutaneous endoscopic polypectomy of gallbladder polyps

We report here our preliminary experience with percutaneous endoscopic polypectomy of gallbladder polyps. Five patients with a total of 17 cholesterol polyps (size: 4-6 mm) and one patient with two gallbladder adenomas (size: 5 mm), four of whom were symptomatic and all of whom refused cholecystectomy, underwent a single-stage procedure under epidural anesthesia. All patients had functioning gallbladders, as assessed by oral cholecystography after stimulation. Following a small incision, the gallbladder was pulled out of the abdominal wall, incised, and a cholecystoscope introduced. The polyps were coagulated at their stalk using microwave irradiation (70-80 mA, 9 sec) and removed for histopathological evaluation thereafter. A catheter was left in situ for ten days. Follow-up for a mean of 11.6 months (8-16 months) showed all patients to be symptom-free and without recurrence of polyps on ultrasonography. Gallbladder function was assessed in five cases by meal-stimulated oral cholecystography, and in one by hepato-iminodiacetate acid (HIDA) scan and was found to be well preserved. The preliminary results warrant further evaluation of this method of removing indeterminate gallbladder polyps.

Promoter-selective transcriptional defect in cell cycle mutant ts13 rescued by hTAFII250

The TAFII250 subunit of the human transcription factor IID (TFIID) rescues the temperature-sensitive hamster cell line ts13 and overcomes a G1 arrest. Investigation of the transcriptional properties of ts13 nuclear extracts in vitro showed that activation by the site-specific regulators Sp1 and Gal4VP16 is temperature sensitive in ts13 extracts, whereas basal transcription remains unaffected. This transcriptional defect can be rescued by purified human TFIID or by expression of wild-type TAFII250 in ts13 cells. Expression from the cyclin A but not c-fos promoter is temperature sensitive in these mutant cells. Thus, the mutation in TAFII250 appears to have gene-specific effects that may lead to the ts13 cell cycle phenotype.

Phosphorylation and active ATP hydrolysis are not required for SV40 T antigen hexamer formation

ATP induces structural alterations in SV40 large T antigen and promotes changes in its interaction with the viral replication origin. We have analyzed nucleotide-induced changes in T antigen structure in the absence of origin DNA. Most preparations of immunopurified T antigen contain several discrete species ranging in size from monomers through oligomers larger than hexamers. The predominant species consist of monomers and dimers. Incubation of T antigen with ATP or dATP leads to a dramatic and rapid increase in the appearance of T antigen hexamers. Weakly and nonhydrolyzable analogs of ATP are effective as well, indicating that hexamer formation does not require active ATP hydrolysis. After incubation of T antigen with [gamma-35S]ATP, stable association of the labeled nucleotide with all detectable forms occurs. Removal of greater than 80% of the T antigen phosphate residues does not significantly affect the formation of T antigen hexamers, although changes in the distribution and mobility of the other species of T antigen are apparent. Furthermore, T antigen synthesized in and purified from Escherichia coli and, therefore, presumably un- or underphosphorylated, is capable of forming hexamers. Nucleotide-induced T antigen hexamer formation thus appears to require neither protein phosphorylation nor active ATP hydrolysis.

The replication functions of polyomavirus large tumor antigen are regulated by phosphorylation

Polyomavirus (Py) large T antigen (T Ag) contains two clusters of phosphorylation sites within the amino-terminal half of the protein. To characterize possible regulatory effects of phosphorylation on viral DNA replication, Py T Ag was treated with calf intestinal alkaline phosphatase (CIAP). Incubation of the protein with a range of phosphatase concentrations caused progressive loss of phosphate without affecting its stability. Treatment with smaller quantities of CIAP stimulated the ability of the viral protein to mediate replication of constructs containing the viral replication origin, while higher concentrations of CIAP caused a marked diminution of this replication function. Several biochemical activities of Py T Ag were examined after CIAP treatment. Py T Ag DNA unwinding and nonspecific DNA binding were only slightly affected by dephosphorylation. However, as determined by DNase I footprinting experiments, treatment with smaller amounts of CIAP stimulated specific binding to the Py replication origin by Py T Ag, while treatment with larger amounts of CIAP caused marked inhibition of origin-specific binding by the viral protein. Phosphotryptic maps of Py T Ag before or after treatment with CIAP revealed changes in individual phosphopeptides that were uniquely associated with either the stimulation or the inhibition of replication. Our data therefore suggest that Py T Ag is regulated by both repressing and activating phosphates.

Paraspinal soft-tissue sarcoma. Classification of 14 cases

Fourteen patients were treated surgically for soft-tissue sarcoma arising in the paraspinal muscles. Eleven patients received adjuvant irradiation administered before or after resection. In describing the treatment and outcomes of these patients, a new classification of paraspinal soft-tissue sarcoma is introduced that is based on the anatomic relationship of the tumor to the spinal lamina and the epidural space. This classification can be used in planning combined modality treatment for paravertebral sarcomas. Lesions that extend through the lamina into the epidural space present an unanswered problem for local control.

Pharmacokinetics and relative bioavailability of lomefloxacin preparations in 10 healthy Chinese volunteers

The pharmacokinetics of lomefloxacin tablet and capsule were determined following a single oral dose of 400 mg given to each of 10 Chinese healthy male volunteers in an open, randomized crossover study. Drug concentrations in plasma were assayed by HPLC method. The peak levels in plasma averaged 6.0 +/- 1.3 and 5.9 +/- 1.0 micrograms.ml-1 at 1.3 +/- 0.4 and 1.2 +/- 0.4 h, and the areas under the drug concentration curves were 43 +/- 15 and 44 +/- 13 h.micrograms.ml-1 for lomefloxacin tablet and capsule, respectively. The concentration-time courses after medication conformed to a 1-compartment open model with a first order absorption. Pharmacokinetic parameters after tablet did not differ significantly from the corresponding values after capsule. The bioavailability of tablet was comparable to that of capsule.

Cloning and expression of human TAFII250: a TBP-associated factor implicated in cell-cycle regulation

Basal transcription by human RNA polymerase II requires the coordinate action of several ancillary factors (TFIIA-J) and can be regulated by various promoter-specific DNA binding proteins. An additional class of factors, called coactivators, are dispensable for basal transcription but are indispensable for regulation by transcriptional activators. Biochemical studies established that some coactivators are associated with the TATA-binding protein (TBP) to form the TFIID complex. We therefore set out to define the relationship between TBP and these TBP-associated factors (TAFs). Here we describe the cloning, expression and properties of the first human TAF, hTAFII250. The hTAFII250 gene is identical to a gene, CCG1, (ref 7,8), implicated in cell-cycle progression. Recombinant hTAFII250 binds directly to TBP both in vitro and in yeast, and participates in the formation of the TFIID complex. This largest TAF may therefore play a central role in TFIID assembly by interacting with both TBP and other TAFs, as well as serving to link the control of transcription to the cell cycle.

Management of long-term postirradiation periclavicular complications

Four cases of periclavicular postirradiation sarcoma and two cases of clavicular osteoradionecrosis with pathologic fractures are reported. All six cases presented more than 10 years after irradiation for breast cancer (five) or nasopharyngeal carcinoma (one). A review of radiotherapy received showed that they were subjected to unconventional radiation schedules (hypofractionation or high dose per fraction treatment). An approach to diagnosis and management of periclavicular lesions arising long after therapeutic irradiation is presented and the unique problems encountered with periclavicular surgery are discussed.

Murine p53 inhibits the function but not the formation of SV40 T antigen hexamers and stimulates T antigen RNA helicase activity

We have characterized the effects of p53 on several biochemical activities of simian virus 40 (SV40) large tumor (T) antigen. While p53 induced a strong inhibition of the T antigen DNA helicase activity, surprisingly, its RNA helicase activity was stimulated. This supports the liklihood that the DNA and RNA helicase activities of T antigen reflect discrete functions. p53 did not significantly affect the ATP-dependent conversion of T antigen monomers to hexamers. However, the ability of these hexamers to assemble on a DNA fragment containing the viral origin was impaired by p53. Thus, these results suggest that p53 inhibits the function but not the formation of T antigen multimers. This conclusion was further supported by the observation that the addition of a purified p53:T antigen complex was as inhibitory as free p53 to the DNA helicase activity of free T antigen. Thus our data indicates that the targets of p53 inhibition are the functional units of T antigen, namely the hexamers.

Osteomyelitis of the calcaneum

We reviewed 52 cases of osteomyelitis of the calcaneum. The clinical symptoms and signs were well defined, but different and less dramatic than those of long-bone osteomyelitis. Blood cultures were positive in 41% of cases and tissue cultures in 91%. Routine haematological tests were of little value, and radiological changes were often delayed, and were absent in 12%. With early diagnosis, treatment with antibiotics alone was usually effective, but complications and chronic disease were more likely if there was delay. Early diagnosis is the key to successful treatment. We describe a new physical sign and consider that diagnosis is almost always possible by clinical methods.

ATP induces the assembly of polyoma large tumor antigen into hexamers

Using zone velocity sedimentation and nondenaturing polyacrylamide gel electrophoresis, we have determined that purified polyoma large tumor antigen (Py T Ag) consists of discrete forms ranging from more abundant monomers and dimers to several higher but clearly distinguishable oligomeric species. Addition of ATP and MgCl2 to Py T Ag caused a dramatic increase in the appearance of Py T Ag hexamers, a form that, based on its SV40 T Ag counterpart, is likely to play a crucial role in its DNA replication functions. Other nucleotides in addition to ATP, as well as a nonhydrolyzable ATP derivative, were capable of inducing hexamer formation. This approach may further elucidate the role(s) of different forms of Py T Ag in viral regulatory processes.

DNA helicase and duplex DNA fragment unwinding activities of polyoma and simian virus 40 large T antigen display similarities and differences

We have characterized the biochemical activities of purified polyoma (Py) large T antigen (T Ag) that was capable of mediating the replication of a plasmid containing the Py origin (ori(+) DNA) in mouse cell extracts. We report here that like the T Ag encoded by simian virus 40 (SV40), Py T Ag has DNA helicase and double-stranded DNA fragment unwinding activities. Py T Ag displaced DNA fragments greater than 1,600 nucleotides which were annealed to complementary sequences in single-stranded M13 by translocating in the 3' to 5' direction. Both helicase and double-stranded DNA fragment unwinding reactions were completely dependent upon NTP hydrolysis, displaying a strong preference for ATP and dATP. At low T Ag concentrations, significantly more Py ori(+) DNA fragment was unwound compared with a fragment lacking the replication origin. However, at higher ratios of Py T Ag to DNA, equivalent to those used in replication reactions, unwinding of both ori-containing and -lacking fragments was equally efficient. This is in contrast to SV40 T Ag which exhibited a more stringent requirement for SV40 origin sequences under similar conditions. Furthermore, some of the nucleotides that supported the helicase and unwinding activities of Py T Ag were different from those for the same SV40 T Ag reactions. We have also observed that in contrast to the very poor replication of linear SV40 ori(+) DNA by SV40 T Ag in human cell extracts, linear Py ori(+) DNA was replicated efficiently in mouse cell extracts by Py T Ag. However, despite the fact that linear Py ori(+), SV40 ori(+), and ori(-) DNA fragments could be unwound with comparable efficiency by Py T Ag, only fragments containing the Py replication origin were replicated in vitro. These results suggest that the initiation of DNA synthesis at the Py origin of replication requires features in addition to unwinding of the template.

The DNA-binding properties of polyomavirus large T antigen are altered by ATP and other nucleotides

We have examined the influence of ATP on the DNA-binding properties of polyomavirus large T antigen (Py TAg). Utilizing nitrocellulose filter binding, DNase I footprinting, and gel mobility shift assays, we observed that ATP increased Py TAg binding to DNA fragments containing either all Py TAg-binding sites (whole origin) or those sites within (core origin) or adjacent to (early) the origin of replication. Even nonspecific binding to DNA fragments lacking Py TAg-binding sites was increased somewhat by ATP. Binding to the core origin was increased to a greater extent than binding to other DNA fragments tested. Gel band mobility shift assays revealed that ATP increased the production of core origin-specific Py TAg-DNA complexes of high molecular weight. ATP stimulation depended on the presence of MgCl2. Other nucleotides and nonhydrolyzable ATP analogs also increased Py TAg binding to the core origin but to various degrees: ATP, dATP, 5'-adenylyl imidodiphosphate (AMPPNP) greater than 5'-adenylyl methylenediphosphate (AMPPCP) greater than dCTP greater than UTP greater than TTP. GTP and dGTP did not increase DNA binding by Py TAg. The rates of association and disassociation of Py TAg with all the DNA fragments were altered by the presence of ATP. DNase I footprinting showed that ATP extensively extended the region protected within the core origin and also produced a distinctive DNase I-hypersensitive site on the late strand at nucleotides 5255 to 5262 (TTACTATG).

[Study of transformation of hamster embryo cells and its application to identification of environment carcinogen]

Cultural cells used were embryo cells collected from pregnant (12-14 days) golden hamster. 3,4B[a] P was used to induce transformation of the cells in vitro. 24 hours after the treatment, there appeared a random arrangement of the cells and loss of the contact inhibition and cell polarity. Some transformed foci were obtained on the 4th day with presence of atypical cells. Scanning electron microscopy showed presence of blebs, considerable ruffling particularly increase of small microvilli, and small projections on the surface of the transformed cells. Karyotypes of the cells showed decrease of diploid cells, but numbers of tetraploid, heteroploid as well as polyploid cells increased. Application of these criteria in identifying carcinogenesis of the industry dust from a zinc-product factory in the west area of Liaoning Province indicated that changes obtained in cells treated by this dust were similar to those obtained by using B[a]P alone. It is considered that carcinogenetic agents of lung cancer are present in the dust in the area.

[Extracorporeal shock wave lithotripsy in the treatment of biliary stones]

From Sep. 1988 to Dec. 1989, 163 patients with gallstones and 7 with choledocholith were treated by biliary extracorporeal shock wave lithotripsy (ESWL). After lithotripsy, ursodeoxycholic acid was administered in 74 patients, and self-made lithoexpulsive in 44 patients. The remaining 52 patients were given both ursodeoxycholic acid and lithoexpulsive. The total rate of stone fragmentation was 97.6%. One hundred and twenty patients were followed up after ESWL. Biliary stones disappeared in 26.6% of the patients within one month after ESWL, in 33.3% within one to three months, and in 36.6% within six to eight months. There were no severe complications. 10.1 percent of the patients had abdominal discomfort during the procedure of ESWL, and cutaneous petechiae were found in 12.2% of the patients. Other complications included biliary colic in 6, jaundice in 2, and hematuria in 2. Serum enzymology and chest X-ray remained unchanged after ESWL.

[Blocking actions of l-stephanine, xylopine and 7 other tetrahydroisoquinoline alkaloids on alpha adrenoceptors]

The blocking action and selectivity of 9 tetrahydroisoquinoline alkaloids on alpha adrenoceptors have been investigated in isolated tissues. Dehydrostephanine and berbamine suppressed the inhibition of clonidine for the electrically stimulated twitch response of rat vas deferens, with pA2 values of 5.36 and 5.49, respectively. l-Crebanine, l-tetrahydrocoptisine, berberine, l-stepholidine and l-tetrahydropalmatine had obvious blocking effects on alpha 1 and alpha 2 adrenoceptors. l-Stephanine and xylopine could competitively inhibit anococcygeus muscle contraction induced by phenylephrine with pA2 values of 6.76 and 6.68, respectively. These 2 alkaloids showed no effect on the inhibition of clonidine for contractile response of rat vas deferens to field stimulation, and their selectivity ratios to block alpha 1 and alpha 2 adrenoceptors were 57.5 and 47.9, respectively. These results indicate that l-stephanine and xylopine are 2 potent and highly selective alpha 1 adrenoceptor blockers.

The murine p53 protein blocks replication of SV40 DNA in vitro by inhibiting the initiation functions of SV40 large T antigen

We have characterized the effect of murine p53 on SV40 DNA replication in vitro. Purified wild-type murine p53 dramatically inhibited the ability of SV40 T antigen to mediate the replication of a plasmid bearing the viral origin (ori-DNA) in vitro. In contrast, polyoma ori-DNA replication in vitro was unaffected by p53. Surprisingly, both unbound p53 and SV40 T antigen-bound p53 were equally detrimental to SV40 ori-DNA replication. Thus, p53 interferes with interactions between T antigen molecules that are required for DNA synthesis. p53 inhibited the binding to and subsequent unwinding of the SV40 origin by T antigen and thus selectively blocked the initial stages of ori-DNA replication. In contrast to the nononcogenic wild-type murine p53, high concentrations of a mutant transforming p53 failed to block SV40 ori-DNA replication in vitro. These observations may provide insight into a possible role for p53 in the cell.