Mapping brain networks in awake mice using combined optical neural control and fMRI

Behaviors and brain disorders involve neural circuits that are widely distributed in the brain. The ability to map the functional connectivity of distributed circuits, and to assess how this connectivity evolves over time, will be facilitated by methods for characterizing the network impact of activating a specific subcircuit, cell type, or projection pathway. We describe here an approach using high-resolution blood oxygenation level-dependent (BOLD) functional MRI (fMRI) of the awake mouse brain-to measure the distributed BOLD response evoked by optical activation of a local, defined cell class expressing the light-gated ion channel channelrhodopsin-2 (ChR2). The utility of this opto-fMRI approach was explored by identifying known cortical and subcortical targets of pyramidal cells of the primary somatosensory cortex (SI) and by analyzing how the set of regions recruited by optogenetically driven SI activity differs between the awake and anesthetized states. Results showed positive BOLD responses in a distributed network that included secondary somatosensory cortex (SII), primary motor cortex (MI), caudoputamen (CP), and contralateral SI (c-SI). Measures in awake compared with anesthetized mice (0.7% isoflurane) showed significantly increased BOLD response in the local region (SI) and indirectly stimulated regions (SII, MI, CP, and c-SI), as well as increased BOLD signal temporal correlations between pairs of regions. These collective results suggest opto-fMRI can provide a controlled means for characterizing the distributed network downstream of a defined cell class in the awake brain. Opto-fMRI may find use in examining causal links between defined circuit elements in diverse behaviors and pathologies.

Structural and functional characterization of a pollen-specific promoter NTPp13 in tobacco

A novel 407 bp nucleotide sequence NTPp13 was isolated from tobacco (Nicotiana tabacum L.) by PCR, its structure and function were characterized. The NTPp13 sequence was highly homologous with the pollen-specific expression promoter Zm13 from maize (Zea mays L.) and contained some key motifs which controlled pollen-specific expression. The NTPp13 was fused to the beta-glucuronidase (GUS) reporter gene and transferred into tobacco. Analysis of the transgenic plants revealed that this putative promoter fragment was sufficient to direct GUS expression specifically in the anther, exactly in the pollen and pollen tube, and that GUS activity reached the maximum at the stage of pollen grain began to separate. Further study showed that the expression of NTPp13 sequence at pollen was stable at the range of temperature measured. These data suggested that the NTPp13 sequence was likely the essential element of promoter region of an unknown pollen-specific gene from tobacco.

Survivin knockdown by short hairpin RNA abrogates the growth of human hepatocellular carcinoma xenografts in nude mice

Abnormal high activation of survivin is involved in carcinogenesis of various types of cancer. Survivin has been shown to promote cell proliferation in human hepatocellular carcinoma (HCC). Survivin-targeting approaches have become a promising strategy for treating HCC. Here, we used a reporter system to screen effective survivin siRNA sequences. The effect of vector-based survivin short hairpin RNA (shRNA) on the malignant phenotype of HCC cells in vitro and in vivo was determined, and an adenovirus-mediated shRNA expression vector was developed to decrease survivin expression of the established HCC tumor in nude mice. In vitro study showed that stable survivin knockdown inhibited cancer cell proliferation, enhanced apoptotic susceptibility, arrested cell cycle in the G1 phase and resulted in apparent mitotic catastrophe. Moreover, cells stably expressing survivin shRNA showed decreased tumorigenicity in nude mice. An additional in vivo study showed that intratumoral injection of adenovirus-delivered survivin shRNA suppressed tumor growth by spontaneous apoptosis of cancer cells and significantly prolonged animal survival. In conclusion, we proved the therapeutic potential of survivin shRNA for the treatment of HCC. And our results indicated that adenovirus-delivered shRNA may serve as a novel therapeutic for HCC.

Simultaneous subsecond hyperpolarization of the nuclear and electron spins of phosphorus in silicon by optical pumping of exciton transitions

We demonstrate a method which can hyperpolarize both the electron and nuclear spins of 31P donors in Si at low field, where both would be essentially unpolarized in equilibrium. It is based on the selective ionization of donors in a specific hyperfine state by optically pumping donor bound exciton hyperfine transitions, which can be spectrally resolved in 28Si. Electron and nuclear polarizations of 90% and 76%, respectively, are obtained in less than a second, providing an initialization mechanism for qubits based on these spins, and enabling further ESR and NMR studies on dilute 31P in 28Si.

[Comparative study of experimental conjugated and combined vaccines against group B streptococci]

Immunogenic properties of recombinant protein ScaAB mixed with polypeptide P6 as well as conjugate of the former with capsular polysaccharide type III (PSIII) were assessed. Protein-polysaccharide conjugate was synthesized by reductive amination method. Immunogenicity was studied on the mouse model using aluminium hydroxide as adjuvant. Antibody titers in antisera were measured by immunoenzyme assay. Functional activity of antibodies was evaluated by opsonophagocytic test. Immunization with ScaAB-PSIII conjugate resulted in increased immune response to both ScaAB and polysaccharide. Administration of ScaAB and P6 proteins mixture compared to their separated administration led to increased of antibody titer and prolonged circulation of specific antibodies. Injection of studied vaccines increased opsonizing activity of antisera compared to immunization with uncombined components.

Establishment of an enzyme-linked immunosorbent assay system for determining soluble CD96 and its application in the measurement of sCD96 in patients with viral hepatitis B and hepatic cirrhosis

CD96, previously named T cell activation increased late expression (Tactile), is a transmembrane molecule that functions as an activated receptor on natural killer cells. It is well known that many transmembrane molecules have soluble forms, which were either shed from the cell surface or spliced at mRNA level. In many cases, the levels of soluble forms in the circulation could be used as biomarkers of lymphocyte activation in bacterial or virus infection, tumour, transplantation and autoimmune disease. To investigate whether CD96 could be released into the sera and the possible biological function of soluble hCD96 (sCD96), we generated and characterized five clones of anti-hCD96 mouse monoclonal antibodies (mAb) and developed a sandwich enzyme-linked immunosorbent assay (ELISA) system based on two anti-hCD96 mAbs with different epitope specificities. Using this ELISA system, sCD96 in serum samples from 99 healthy individuals could be detected. Furthermore, we found that the level of sCD96 in serum samples from patients with chronic viral hepatitis B or classes B and C of hepatic cirrhosis classified using the Child-Pugh score was much higher (P < 0.001 versus healthy individuals; P = 0.006 versus healthy individuals respectively) than that from healthy individuals (0.98 ng/ml). Our study demonstrates for the first time that sCD96 existed in sera, and suggests that sCD96 may be used as a serous marker for some diseases such as chronic viral hepatitis B infection or hepatic cirrhosis in classes B and C. The level of sCD96 in patients' serum may have some relationship with a chronic inflammatory reaction.

Reduction of the linewidths of deep luminescence centers in 28Si reveals fingerprints of the isotope constituents

Dramatic reductions of the linewidths of well-known deep centers in 28Si reveal "isotopic fingerprints" of the constituents. The approximately 1014 meV Cu center, thought to be either a Cu pair or an isolated Cu, is shown to contain four Cu atoms, and the approximately 780 meV Ag center is shown to contain four Ag. The approximately 944 meV ;{*}Cu center, thought to be a different configuration of a Cu pair, in fact contains three Cu and one Ag, and a new two-Cu two-Ag center is found. The approximately 735 meV center, previously assigned to Fe, actually contains Au and three Cu. This suggests a family of four-atom (Cu, Ag, Au) centers.

Endoscopic ultrasound-guided interstitial chemotherapy in the pancreas: results in a canine model

BACKGROUND AND STUDY AIM

Interstitial chemotherapy using surgically implanted, biodegradable polymers has been reported. Our aim in this study was to investigate the feasibility and safety of endoscopic ultrasound- (EUS-) guided interstitial chemotherapy of the pancreas in a canine model.

MATERIALS AND METHODS

A therapeutic 19-gauge needle with a large channel was inserted into the pancreas under EUS guidance. The polymers for sustained intratumoral release of 5-fluorouracil were implanted into the tissue by the needle. After 14 days of clinical observation, the animals were sacrificed and the tissue response to the local chemotherapy was examined.

RESULTS

All the polymers were implanted successfully and no implant migration occurred. Localized tissue fibrous necrosis was achieved in the pancreas, without significant complications. The apoptotic index of the tissue within 1 cm of the focus increased. Biochemical parameters were normal in all the dogs.

CONCLUSIONS

EUS-guided implantation of polymers is a safe, simple, and minimally invasive technique for interstitial chemotherapy in the pancreas.

Optical detection and ionization of donors in specific electronic and nuclear spin States

We resolve the remarkably sharp bound exciton transitions of highly enriched 28Si using a single-frequency laser and photoluminescence excitation spectroscopy, as well as photocurrent spectroscopy. Well-resolved doublets in the spectrum of the 31P donor reflect the hyperfine coupling of the electronic and nuclear donor spins. The optical detection of the nuclear spin state, and selective pumping and ionization of donors in specific electronic and nuclear spin states, suggests a number of new possibilities which could be useful for the realization of silicon-based quantum computers.