[Effect of thyroxine on the expression of HIF-1α after aneurysmal subarachnoid hemorrhage in rat brain and its mechanism].

Objective: To investigate the effect of thyroxine (T4) on the expression of hypoxia inducible factor-1α (HIF-1α) in rat brain after aneurysmal subarachnoid hemorrhage (SAH) and its mechanism. Methods: Seventy-two adult male SD rats were randomly divided into the following 4 groups: subarachnoid hemorrhage model group(SAH), subarachnoid hemorrhage model and T4 group (SAH with T4), subarachnoid hemorrhage model with normal saline group (SAH with vehicle), and sham-operation group, 18 rats in each group. The model of subarachnoid hemorrhage group was established by internal carotid artery puncture. CT plain scan was performed after the modeling immediately, T4 was administrated by intraabdominal injection of 3 µg/100 g every 24 hours for 3 days. SAH with T4 group was treated with thyroxine. SAH with vehicle group was treated with equal volume vehicle, all of them were killed 72 hours after modeling. The brain water content was determined to evaluate the brain edema, the apoptosis of cerebral cortex cells was detected by TUNEL method, and HIF-1α protein and p-Akt protein in cerebral cortex were detected by immunohistochemistry in six SD rats of each group. Results: After the modeling, the brain tissues of SAH group, SAH + T4 group and SAH +vehicle group were swollen obviously, and blood clots were observed in subarachnoid space. The neurobehavioral score,the brain water content, apoptosis index, HIF-1α protein and p-Akt protein in SAH group were significantly higher than those in sham-operation group(P＜0.05).The neurobehavioral score,HIF-1α protein and p-Akt protein in SAH with T4 group were significantly higher than those in SAH group, and the brain water content, apoptosis index were significantly lower than those in SAH group (P＜0.05). Conclusion: The expression of HIF-1α protein in the brain of rats after aneurysm subarachnoid hemorrhage can be upregulated by T4 replacement therapy, which may by activating the signal pathway of inositol triphosphate kinase / protein kinase B (PI3K/Akt). Finally, apoptosis index was decreased, the rat behavior was improved and the brain was protected.

Trace eyeblink conditioning is associated with changes in synaptophysin immunoreactivity in the cerebellar interpositus nucleus in guinea pigs.

Synaptic plasticity plays a role during trace eyeblink conditioning (TEBC). Synaptophysin (Syn) is a major integral transmembrane protein, located particularly in the synaptic vesicles, and is considered a molecular marker of synapses. In addition, Syn immunoreactivity is an important indicator of synaptic plasticity. In the present study, we used immunohistochemical techniques to assess changes in Syn expression in the cerebellar interpositus nucleus (IN) of guinea pigs exposed to TEBC and pseudoconditioning. Additionally, we analyzed the relationship between Syn immunoreactivity and the percentage of trace-conditioned responses. Guinea pigs underwent trace conditioning or pseudoconditioning. Following two, six, or ten sessions, they were perfused and the cerebellum was removed for Syn immunohistochemical evaluation. After sessions 6 and 10, a significant increase in conditioned response (CR) percentage was observed in the trace-conditioned group, with the CR percentage reaching the learning criteria following session 10. Besides, for trace-conditioned animals, the Syn expression in IN was found significantly up-regulated after session 10 compared with pseudoconditioned ones. Our data suggest that the increase in Syn expression links to synaptic plasticity changes in the cerebellar IN and provides a histological substrate in the IN relating to TEBC training. The changing trend of Syn immunoreactivity in the IN is associated with CR percentage.

Antitumor efficiency of the cytosine deaminase/5-fluorocytosine suicide gene therapy system on malignant gliomas: an in vivo study.

BACKGROUND: Suicide gene therapy, particularly that utilizing the cytosine deaminase/5-fluorocytosine (CD/5-FC) system, represents a novel and attractive methodology of cancer research. Mechanistically, the CD enzyme can convert the antifungal agent 5-FC into the antimetabolite agent 5-fluorouracil (5-FU), thereby killing tumor cells. The purpose of this study was to investigate the antitumor efficiency of the CD/5-FC system in malignant gliomas using a nude mouse model. MATERIAL/METHODS: The eukaryotic expression plasmid pCMV-CD was transfected into U251 malignant glioma cells. Resistant clones (labeled U251/CD cells) were subsequently isolated and further confirmed by reverse transcription polymerase chain reaction (RT-PCR), immunofluoroscence, and immunoblot. Then U251/CD cells were incubated with 5-FC at various concentrations to measure viability ratios as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. 5-FU concentrations in the media were measured by high-performance liquid chromatography (HPLC). Finally, the volumes and weights of tumors from glioma-bearing nude mice after 5-FC intervention were evaluated. RESULTS: The results revealed that the untreated U251 cells were insensitive to 5-FC whereas the U251/CD cells were highly sensitive. Apoptosis and cell death were observed on the U251/CD cells after 5-FC administration. HPLC analysis showed that 5-FU was detected in the U251/CD cell media. These in vivo animal data showed that the volumes and weights of the implanted tumors were dramatically decreased due to cell apoptosis and tumor necrosis. CONCLUSIONS: The in vivo results encourage a further investigation in a controlled trial on the treatment of malignant gliomas via the CD/5-FC gene therapy system.

[Anatomical study and three dimensional image characteristic analysis of basicranial artery and its clinical significance].

OBJECTIVE: To observe and measure the inside diameter of basicranial arteries, the angulation of main arteries, the three dimensional image characteristic of internal carotid arteries and the anatomical variation of Willis circle. METHODS: The arteries of 30 formalin-fixed adult heads were injected with latex after which the caliber and characteristic of cerebral arteries were observed and measured. The three dimensional image characteristic of internal carotid arteries and its branches were measured using 3D-DSA. RESULTS: (1) Main artery caliber: origin of internal carotid artery (Left 5.12 +/- 1.48 mm; Right 5.11 +/- 1.42 mm); origin of middle cerebral artery (Left 2.93 +/- 1.44 mm; Right 2.92 +/- 1.46 mm); origin of anterior cerebral artery (Left 2.63 +/- 1.33 mm; Right 2.61 +/- 1.32 mm); origin of vertebral artery (Left 4.37 +/- 1.21 mm; Right 3.22 +/- 1.64 mm); origin of basilar artery (4.45 +/- 1.28 mm); origin of posterior cerebral artery (Left 2.62 +/- 1.36 mm; Right 2.61 +/- 1.22 mm). (2) The angulation of main arteries: C1, 2 of ICA and C4, 5 of ICA (Left 32 +/- 22 degrees; Right 36 +/- 28 degrees ); ICA and ACA (Left 43 +/- 26 degrees; Right 46 +/- 28 degrees). (3) The results show that anatomical and three dimensional image characteristic of internal carotid arteries have no difference (P > 0.05). (4) The anatomical variation of Willis circle: Type O (56.7%); Type A (16.7%); Type P (20.0%); Type AP (6.7%). CONCLUSIONS: It is helpful to measure the inside diameter of basicranial arteries for the selection of various catheter in interventional neuroradiology, to observe the angulation of main arteries and the three dimensional image characteristic of internal carotid arteries for the moulding of various catheter in endovascular therapy and to master the anatomical variation of Willis circle for decreasing complications of endovascular treatment and judging prognosis of cerebrovascular diseases.

The phylogenetic utility of nucleotide sequences of sorbitol 6-phosphate dehydrogenase in Prunus (Rosaceae).

Sequences from s6pdh, a gene that encodes sorbitol-6-phosphate dehydrogenase in the Rosaceae, are used to reconstruct the phylogeny of 22 species of Prunus. The s6pdh sequences alone and in combination with previously published sequences of the internal transcribed spacer (ITS) and the cpDNA trnL-trnF spacer are analyzed using parsimony and maximum likelihood methods. Both methods reconstructed the same phylogeny when s6pdh sequences are used alone and in combination with ITS and trnL-trnF, and the topology is in agreement with previous studies that used a larger sample size. The s6pdh sequences have about twice as many informative sites as ITS. A molecular clock is rejected for s6pdh, most likely due to greater rates of evolution in subgenera Padus and Laurocerasus than in the rest of the genus. Phylogenetic reconstruction of Prunus as determined by analysis of the combined data set suggests an early split into two clades. One is composed of subgenera Cerasus, Laurocerasus, and Padus. The second includes subgenera Amygdalus, Emplectocladus, and Prunus. Species of section Microcerasus (formerly in subgenus Cerasus) are nested within subgenus Prunus. The order of branching and relationships among early diverging lineages is weakly supported, as a result of very short branches that may indicate rapid radiation.