An experimental study of acute radiation-induced cognitive dysfunction in a young rat model

BACKGROUND AND PURPOSE

Radiation-induced cognitive dysfunction is a common and serious clinical complication after radiation therapy for a brain tumor, but the knowledge of its mechanism is poorly understood. The purpose of this study was to establish a young rat model for acute radiation-induced cognitive dysfunction and associated BBB damage, as well as histopathologic changes.

MATERIALS AND METHODS

Young male rats were randomized into 4 groups to receive irradiation treatments at 300 cGy/min with doses of 0 (sham), 10, 20, and 40 Gy, respectively. Each treatment group was further randomized into 4 subgroups for following up cognitive tests and assessment of their BBB integrity and potential histopathologic changes at 0, 7, 20, and 60 days.

RESULTS

We found that irradiation at 10 Gy failed to induce any significant effects. Irradiation at 20 Gy resulted in a transient impairment of the cognitive functions at 7 and 20 days and returned to normal at 60 days. Irradiation at 40 Gy caused the severest cognitive impairment, which peaked at 7 days, and lasted for at least 60 days. The impaired cognition in both the 20-Gy and 40-Gy-irradiated rats was more or less accompanied with increased brain water content and deteriorated BBB function, though mild histopathologic alternations were only noticed in the 40-Gy-irradiated rats at 20 days.

CONCLUSION

A single-dose exposure at 20 to 40 Gy is sufficient to induce acute brain injury at both cognitive and pathologic levels in young male rats. In addition, morphologic outcomes may not be sensitive enough to reveal all of the pathologic changes, whereas BBB disruption may be an earlier and more sensitive index for acute RE. Therefore, the present model is useful for basic and therapeutic studies of acute RE.

Altered global gene expressions of human placentae subjected to assisted reproductive technology treatments

BACKGROUND

Researchers are more and more concerning the safety of fetus or offspring derived from assisted reproductive technology (ART) treatment. As the placenta is a critical organ that sustains and protects the fetus, we hypothesize that altered global gene expression of the placenta subjected to ART manipulation may reflect changes associated with ART procedures and subsequently causal related to offspring health.

METHODS

Three term placenta samples were obtained from patients undergone in vitro fertilization and embryo transfer due to oviductal factors only. Other three control placentae were from those underwent normal pregnancy. A GeneChip Affymetrix HG-U133 Plus 2.0 Array was utilized to analyze the genes. Using qRT-PCR we certified microarray data from 10 dysregulated genes. Five genes were localized precisely in the placenta as per immunohistochemistry.

RESULTS

Twenty-six differentially expressed genes were identified in the ART-treated placentae: 17 up-regulated; 9 down-regulated. Eighteen of these were classified into six groups according to critical placental function: immune response; transmembrane transport; metabolism; oxidative stress; cell differentiation; and other functions. Genes involved in immune response, such as ERAP2 and STAT4, and those regulating cell differentiations, such as MUC1, were discerned to be differentially expressed. These gene products were expressed in the placental villus tissues, either in the cytoplasm or in the membrane of syncytiotrophoblastic cells.

CONCLUSION

To our knowledge, this is the first study in comparing differentially expressed genes in placentae from patients undergone ART treatment vs. those underwent normal pregnancy. Abnormal profiles of critical placental functioning genes, such as ERAP2, STAT4 and MUC1, may be valuable biomarkers to understand how the placenta affects fetal development and ART-derived offspring's health problems.

Strange quark contributions to parity-violating asymmetries in the backward angle G0 electron scattering experiment

We have measured parity-violating asymmetries in elastic electron-proton and quasielastic electron-deuteron scattering at Q2=0.22 and 0.63 GeV2. They are sensitive to strange quark contributions to currents in the nucleon and the nucleon axial-vector current. The results indicate strange quark contributions of approximately < 10% of the charge and magnetic nucleon form factors at these four-momentum transfers. We also present the first measurement of anapole moment effects in the axial-vector current at these four-momentum transfers.

Development of boron-efficient near isogenic lines of Brassica napus and their response to low boron stress at seedling stage

Rapeseed (Brassica napus) is sensitive to low boron (B) stress and plentiful variation exists in response to B deficiency. One major QTL, BE1, and three minor loci controlling B efficiency in Brassica napus were previously detected. To fine map and clone the B-efficient gene (s), the development of B-efficient NILs in Brassica napus was conducted, combining the identification of B efficiency at seedling stage with genetic background selection using random AFLP markers. The molecular marker assisted background selection proved its optimum and necessary in an early backcrossing generation to select the backcross individuals with high genetic background similarity to accelerate the construction of NILs. Based on B efficiency investigated at seedling stage under the low B conditions, the B-efficient backcross line can produce biomass twice about the B-inefficient parent's and show low B concentration and effective utilization of B under low B condition. Thus, the B efficiency of the B efficient NILs might be attributed to the higher B utilization efficiency or less demand for B.

388 OPTIMIZATION OF INDUCED PLURIPOTENT STEM CELL GENERATION FROM BOVINE FIBROBLASTS

Difficulties associated with isolation and culturing bovine embryonic stem (ES) cells has led to the exploration of alternative methods for generating pluripotent stem cells. The viral delivery of reprogramming factors Oct4, Sox2, cMyc, and Klf4 has resulted in generation of induced pluripotent stem cells (iPS) in rodent, human, rhesus monkey, and pig somatic cells. In the current study, we improved the efficiency of retroviral transduction of bovine adult fibroblasts (BAF) for the generation of bovine iPS cells. Bovine adult fibroblasts were transduced with 4 human factors: Oct 4, Sox 2, cMyc, and Klf4. To determine transfection efficiency, pMXs-GFP was used as a reporter. The effect of change in cell density of the Platinum A retroviral packaging cell line (Plat A), cell densities of the target BAF, and infection regimes on the transfection rates was examined. A reduction in Plat A cell density from 8 × 106 to 2 × 106 did not alter transfection rates. Reduced target cell density from 4 × 105 to 4 × 104 (10-fold) improved the transfection rates from 0.31 to 7.06%, P < 0.001 (n = 3). Subjecting the BAF to 2 sequential rounds of viral transduction further improved the transfection rates to 13.88%, P < 0.001 (n = 3). These preliminary results suggest that optimizing the density of target cells can greatly improve transduction outcomes. Following viral induction with the 4 reprogramming factors, putative bovine iPS colonies were observed when the transfection rate was >1%. The putative bovine iPS cells were cultured in alpha-minimal essential medium supplemented with 20% FCS and 10 ng mL-1 human leukemia inhibitory factor. These putative bovine iPS colonies had mouse ES-like morphology, were multilayered, and had high nucleus-to-cytoplasmic ratio. They stained positive for alkaline phosphatase activity. The colonies were manually passaged onto mitomycin C-inactivated mouse embryonic fibroblasts every 5 to 7 days but could only be expanded for a limited number of passages. Other strategies are currently being explored to improve stable reprogramming of BAF such as epigenetic modification of cells, lentivirus-mediated transduction, and investigation of media suitable to maintain putative bovine iPS colonies for further characterization including RT-PCR or immunohistochemical detection for pluripotent markers and in vivo differentiation ability. Acknowledgments are given to Dairy Australia.

Central mucoepidermoid carcinoma of the maxilla: a case report

BACKGROUND AND OBJECTIVE

Primary mucoepidermoid carcinoma of the jaw is a rare lesion, comprising 2-3% of all mucoepidermoid carcinomas reported in literature. Central mucoepidermoid carcinoma of the maxilla is rarer, comprising only 8% of the mucoepidermoid carcinomas found in the jaw.

METHODOLOGY

A 52-year-old man suffered from central mucoepidermoid carcinoma of the right maxilla with cervical metastasis, and underwent partial maxillectomy and neck dissection in our hospital. The diagnosis was confirmed by histopathology, dental orthopantomography, CT, and PET/CT scans.

RESULT

The man was followed-up regularly and was disease free after 21 months.

CONCLUSION

Primary central mucoepidermoid carcinoma of the jaw is a rare lesion and radical surgical resection is the preferred treatment.

Endovascular treatment of wide-neck middle cerebral artery aneurysms with stents: a review of 16 cases

BACKGROUND AND PURPOSE

MCA aneurysms are common and often pose technical challenges to interventionalists. Intracranial stents are widely used in treating wide-neck aneurysms in other locations. To evaluate the feasibility, effectiveness, and safety of stent placement in MCA aneurysms, we performed this retrospective study.

MATERIALS AND METHODS

Between October 2003 and May 2009, 16 patients with 16 wide-neck MCA aneurysms were treated with stents at our institution. We retrospectively collected and analyzed the data for these patients, including demographics, morphologic features of the aneurysms, treatment results, and follow-up.

RESULTS

Seventeen stents, including 12 Neuroform, 4 LEO, and 1 Enterprise, were successfully deployed in this series. Of the 13 aneurysms treated with stent-assisted embolization, complete occlusion was achieved in 9 aneurysms; residual neck remained in 1, and residual aneurysm was present in 3. Contrast stasis in the aneurysm sac was observed in the other 3 aneurysms treated with stent alone. Procedure-related complication occurred in 1 patient, leading to no permanent effect. The mRS score at discharge was 0-2 in 14 patients and 3-6 in 2. The angiographic follow-up results of 9 patients (mean, 5.6 months) showed that all aneurysms remained stable or improved; there was no in-stent stenosis, recurrence, or retreatment. The clinical follow-up (mean, 20.1 months) demonstrated no neurologic deterioration or rebleeding.

CONCLUSIONS

Our preliminary experience demonstrates that stent placement for the treatment of selected wide-neck MCA aneurysms is feasible. However, its safety and efficacy should be further evaluated by larger case series and more adequate follow-up.

Azimuthal charged-particle correlations and possible local strong parity violation

Parity-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the system's orbital momentum axis. We investigate a three-particle azimuthal correlator which is a P even observable, but directly sensitive to the charge separation effect. We report measurements of charged hadrons near center-of-mass rapidity with this observable in Au + Au and Cu + Cu collisions at square root of s(NN) = 200 GeV using the STAR detector. A signal consistent with several expectations from the theory is detected. We discuss possible contributions from other effects that are not related to parity violation.

Activity identification of chimeric anti-caspase-3 mRNA hammerhead ribozyme in vitro and in vivo

To study the expression activity of various vectors containing anti-caspase-3 ribozyme cassettes in vivo, and to further study the role of caspas-3 in the apoptotic pathway, we constructed anti-caspase-3 hammerhead ribozyme embedded into the human snRNA U6, and detected the activity of the ribozyme in vitro and in vivo. Meanwhile we compared it with the self-cleaving hammerhead ribozymes that we previously studied, and with the general ribozyme, cloned into RNA polymerase II expression systems. The results showed that the three ribozymes, p1.5RZ107, pRZ107 and pU6RZ107 had the correct structure, and that they could cleave caspase-3 mRNA exactly to produce two fragments: 143nt/553nt. p1.5RZ107 has the highest cleavage efficiency in vitro, almost 80%. However, the U6 chimeric ribozyme, pU6RZ107, has the highest cleavage activity in vivo, almost to 65%, though it has lower cleavage activity in vitro. The cleavage results demonstrated that the pU6RZ107, the U6 chimeric ribozyme, could more efficiently express and downregulate the level of caspase-3 in vivo, and the ribozyme could provide an alternative approach to the research into the mechanism of apoptosis and human gene therapy also.

Exon structure requirements for yeast tRNA ligase

Different nucleotides were introduced into nucleotides 32, 37 and 38 of yeast tRNA(Phe) precursors via oligonucleotide directed mutations. Pre-tRNAs were prepared using T7-transcription in vitro and spliced with the purified yeast tRNA endonuclease and tRNA ligase. It is demonstrated that tRNA ligase activities will be inhibited by the 5'-double-stranded end of 3'-halves.