The location, shape and internal architecture of the sinoatrial node (SAN) were studied histologically in serial section in 15 hearts (7 adults, 8 foetuses). Based on our observation, the human SAN may be divided into four layers, namely, (1) thesinoatrial node artery layer: its outer longitudinal muscular layer of its media partly lacked in the SAN concentrically; (2) the periarterial layer: the cells of this layer surround the artery concentrically; (3) the central layer, making up the main mass of the node: most P cells in which are arranged parallel to the node artery. In adult the diameter of P cells in this layer is 5.18 ?m; (4) the peripheral layer: most transitional cells in this layer radiate from SAN into the atrial muscle. These "tongues of transitional cells" extend mostly into right atrial-muscle and a few into the musculature of superior vena cava. The diameter of transitional cells of this layer in the adult is 7.28 ?m. In the adult the arrangement of dense collagen fibers appears circular in the periarterial layer, longitudinal in the central layer and radiative in the peripheral layer. According to the location, layers of sinoatrial node and the arrangement of the connective tissue, the functional significance and morphological basis of the re-entry are discussed.

OBJECTIVETo evaluate the effects of thermal and mechanical cycling on the metal-ceramic bond strength of machine-milled Ti2448 alloy and commercial pure titanium (cp Ti).

METHODSCeramic-cp Ti (n = 30) specimens and ceramic-Ti2448 combinations (n = 30) were prepared in accordance with ISO 9693. The specimens from each metal-ceramic combination were randomly divided into three subgroups. In group A or the control group, the specimens were only stored in distilled water for 24 h at 37 °C; in groups B and C, the specimens were subjected to 3,000 cycles of thermal cycling between 5 and 55 °C for a dwell time of 60 s and to mechanical cycling of 20,000 or 40,000 cycles with 50 N load and 4 Hz in distilled water at 37 °C. A crack initiation test was performed using a universal testing machine in accordance with ISO 9693. Failure types at the metal-ceramic interface and the morphological and elemental composition of this interface were analyzed using a scanning electron microscope and an energy dispersive spectrometer. Statistical analysis was performed via two-way ANOVA and Tukey's adjustment test (α = 0.05).

RESULTSThe bond strength of the ceramic-Ti2448 combination was significantly higher than that of the ceramic-cp Ti combination regardless of fatigue conditions (44.86 MPa ± 1.75 MPa and 29.21 MPa ± 2.20 MPa for Ti2448 and cp Ti, respectively; P < 0.01). The mean bond strengths of ceramic-cp Ti and ceramic-Ti2448 combinations in group C were significantly lower than that of group A (P < 0.01). Although ceramic-cp Ti combination failed adhesively at the metal-ceramic interface without the ceramic on the substrate surface, Ti2448 frameworks exhibited cohesive failure; as a result, large amounts of residual porcelain were retained on the specimens.

CONCLUSIONThe metal-ceramic bond strength of cp Ti and Ti2448 is decreased by thermal and mechanical cycling.

100 kDa respectively. \ \{Conclusion\ Eight\} protein bands out of 26 soluble antigen bands of the parasite showed high immunogenicity. There were 9 main polypeptide spots in 43 polypeptide spots of the parasite.

Objective To investigate the expression and distribution of leptin in pre-implantation embryo,and its effect on mouse embryo development in vitro. Methods Adult NIH female mice were superovulated and then mated with fertile males of the same strain. On the morning of 1st to 4th d of pregnancy,the oviduct and horn of uterus were dissected out and flushed with DMEM/F12 medium adequately. The embryos collected were subjected to the following procedures: ①Total RNA was isolated from embryos of each stage respectively and mRNA expression of leptin was detected by RT-PCR. ②Immunofluorescence staining was performed on blastocysts to analyze the expression and the distribution of leptin protein under laser confocal microscope. ③Eight-cell embryos were cultured in medium containing leptin antibody at various concentrations to observe the formation and hatching of blastocysts. Results ①Leptin mRNA expression was only detected in blastocyst,and no expression was detected in embryos in other stages. Leptin protein was detected in cytoplasma,membrane of trophoblastic cell and inner cell mass,however no expression was detected in cell nucleus. ②Leptin polyclonal antibody significantly inhibited formation of blastocysts (1∶400,P

Objective To optimize the extract technology of Quyou Tincture with orthogonal design.Methods With the determination of peoniflorin and paeonol and the extraction rates as indexes,the extract conditions of Quyou Tincture was optimized by orthogonal design.Results The optimal preparation process of alcohol was as follows:adding 6 times alcohol(75%),immerse 24 hours and percolate with 1 mL/min.Conclusion The optimum extracting condition was simple,with a high extraction rate and low cost.

Objective To prove whether it is availble to define the penumbra histopathologically and immunohistopathologically by observing the MRI T 2 imaging,cytoskeleton and neuron changing. Methods Seven cases of autopsy infarct brain with different ischemic time were studied in our program. By MRI T 2 imaging, the fixed brains were examined. Large section of whole brain, and small section of different parts,in and out of the infarct area, and the opposite hemisphere were observed. After observing the neuron, cytoskeleton, microglia, astrocyte, vessel, and also some cytokines by histological and immunohistochemical methods, we divide the ischemic and surrounding areas into four different parts as to seeing the different changes. Results In area 0, the neuron, gliocyte and vessel were all necrotic, eosinocytes developed, and cytoskeletons disappeared. In area 1, there were large number of dark neurons, shrinking cells with heavily destroyed, cytoskeleton, active microglia and inflammatory cells. In area 2, there were a few ischemic neurons , a few dark neurons, and normal neurons,and were also lots of active astrocyte and microglial. The proportion of area 2 was reduced sharply in two days. The ischemic proportion shown by MRI was smaller than that shown by large section of the whole brain. MRI T 2 imaging showed only the area 0 and area 1 with T 2 value increasing, and not showed the area 2 with normal T 2 value. In area 3, the cells were all in normal shape.However,the active microglia and astrocyte hyperplasia, together with the positive TGF ? and TNF? expression, existed in area 3 in all seven brains.Conclusions Area 0 is the infracted mature area, area 1 is the irreversible area, both of them are centers of the necrotic area. Combined with MRI, neuron and cytoskeleton changes, we conclude that area 2 is the possible reversible damage area, or the equal area of penumbra. Area 3 is the response area to ischemic damage, which in some authors’studies was called‘penumbra’.

Objective To access the relation between the Doppler waveform of the hepatic venous flow and the hepatic fibrosis.Methods To construct fibrosis models,20 experimental rabbits were fed with thioacetamide as the only drinking water at the concentration of 1.2 g/L,then the Doppler waveforms of the hepatic vein were detected at the time before constructing the fibrosis model,then later the 8th week,12th week and 16th week during constructing the fibrosis models,the results were compared with the hepatic biopsy ones.Results With the process of constructing the fibrosis models,the experimental rabbits had more abnormal Doppler waveforms of the hepatic venous flow.Conclusions The changes of the Doppler waveforms of the hepatic venous flow reflect the change of hepatic parenchyma.

Objective To study and evaluate the effects of Kanglaite Injection (KLT) in rat model of cancer pain. Methods According to Medhurst' method, a rat model of cancer-induced bone pain wasestablished by intra-tibial injection of 3?103 MRMT-1 rat mammary gland carcinomal cells in Sprague-Dawley rats. KLT group were treated with 10 mL/kg of KLT, ip, twice daily from day 8 to day 17 after injection of MRMT-1 cells. In celecoxib group, 30 mg/kg, ig, twice daily for 10 days. NS group and sham group were given with 10 mL/kg of NS, ip, twice daily for 10 days. On day 17, rats in morphine group received a single administration of 3 mg/kg morphine. Pain-related behaviors including allodynia (the hind paw withdrawal response to 2 g von Frey filament stimulation) and the difference of weight bearing between hind paws were measured in all 5 groups on day 17. In addition, the left hind limbs were removed and X-rays were obtained for assessing of tumor-induced bone destruction. Results On day 17 after injection of MRMT-1 cells or NS, the paw withdrawal response frequency to 2 g von Frey filament stimulation on the left paw in KLT group, celecoxib group, morphine group and NS group were 53.3%?20.7%, 46.7%?20.7%, 13.3%?16.3% and 90% ?16.7%, respectively. The paw withdrawal response frequency in KLT group was significantly decreased compared with that in NS group (P

Objective To study the therapeutic effect and mechanism of Jiawei Xiaochengqi Decoction on hepatic injures by endotoxin in rats. Methods Endotoxemia model of Wistar rats was made by thioacetamide. Blood biochemistry and pathological changes were examined to observe the effect of Jiawei Xiaochengqi decoction on liver function, TNF-?, endotoxin of the model rats. Results Jiawei Xiaochengqi Decoction could reduce the contents of TNF-?, endotoxin in the blood and the degree of hepatic cells necrosis of Wistar rats. There was significant difference compared with model group (P