Lymphatic and Blood Vessels of the Aged Human Gingiva1

The lymphatic pathways in the gingivae from aged humans were traced by the use of the PAS reaction or iron hematoxylin stain, and their structural characteristics were compared to those of the blood microvasculature. In the young and aging gingivae the lymphatic capillaries originated in the connective tissue papillae of the lamina propria, and appeared as thin walled irregular shaped vessels. The adjacent blood capillaries in aged gingivae differed in that their walls were thicker and stained intensely Schiff positive than seen in young adult gingivae. The lymphatic capillaries emptied into thin walled collecting vessels of varying calibers that course through the lamina propria to reach the main conducting vessels that contained valves projecting within its lumen. The accompanying blood vessels were easily differentiated from the lymphatic vessels by the intense positive staining of their walls following exposure to the PAS reaction. Distended lymphatic vessels of different caliber were demonstrable in inflamed aging gingivae, suggesting that lymphatic vessels in the aged gingivae were able to provide a drainage system for excessive fluid, proteins, and other particulates from both non-injured and injured sites.     

Kyphoplasty for the Treatment of Pain Distant to Osteoporotic Thoracolumbar Compressive Fractures

Vertebral fractures are one of the most common osteoporotic fractures. We sought to investigate the incidence of distant pain after osteoporotic vertebral compressive fracture (OVCF) at the thoracolumbar junction, and to explore the effect of kyphoplasty in the treatment of distant pain post-OVCF. Eighty-seven patients diagnosed OVCF between T11 and L2 were included in the study. The region of pain and its proximity to the thoracolumbar compressive fracture was recorded. For pain management, all patients received kyphoplasty. The follow-up period was every 3 months for 1-year post-surgery. The Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) were used pre-operatively, post-operatively, and at 3-, 6-, and 12-month follow-ups to assess patient status. All patients completed the operation, with 72 patients having focal pain over the compression fracture. Eleven cases also had pain distal to the fracture region in the following areas: lower back, near the iliac crest (n = 6), the groin (n = 3), and the trochanteric region (n = 2). Four cases had pain in distant to the fracture: lower back, near iliac crest (n = 3), and the trochanteric region (n = 1). All patients had a significant improvement in clinical symptoms. The average VAS and the ODI decreased significantly pre-operatively to post-operatively (p < 0.05). In addition to focal tenderness, many patients with thoracolumbar compression fractures may have pain distant to the fracture. This can be successfully treated using kyphoplasty. This phenomenon also indicates that patients at risk of osteoporosis who also have lower back pain should not neglect the potential for a thoracolumbar fracture.     

Lymphatic Territories (Lymphosomes) in a Canine: An Animal Model for Investigation of Postoperative Lymphatic Alterations

Background

Lymph node dissection is often performed as a part of surgical treatment for breast cancer and malignant melanoma to prevent malignant cells from traveling via the lymphatic system. Currently little is known about postoperative lymphatic drainage pattern alterations. This knowledge may be useful for management of recurrent cancer and prevention of breast cancer related lymphedema. We mapped the complete superficial lymphatic system of a dog and used this canine model to perform preliminary studies of lymphatic architectural changes in postoperative condition.

Methods

Lymphatic territories (lymphosomes) were mapped with 4 female mongrel carcasses using an indocyanine green (ICG) fluorescent lymphography and a radiographic microinjection technique. Two live dogs were then subjected to unilateral lymph node dissection of lymph basins of the forelimb, and ICG lymphography and lymphangiogram were performed 6 months after the surgery to investigate lymphatic changes. Lymphatic patterns in the carcass were then compared with postoperative lymphatic patterns in the live dogs.

Results

Ten lymphosomes were identified, corresponding with ten lymphatic basins. Postoperative fluorescent lymphographic images and lymphangiograms in the live dogs revealed small caliber lymphatic network fulfilling gaps in the surgical area and collateral lymphatic vessels arising from the network connecting to lymph nodes in the contralateral and ipsilateral neck in one dog and the ipsilateral subclavicular vein in another dog.

Conclusion

Our canine lymphosome map allowed us to observe lymphatic collateral formations after lymph node dissection in live dogs. This canine model may help clarify our understanding of postoperative lymphatic changes in humans in future studies.     

The Repair Response to Osteochondral Implant Types in a Rabbit Model

Current treatments for damaged articular cartilage (i.e., shaving the articular surface, perforation or abrasion of the subchondral bone, and resurfacing with periosteal and perichondrial resurfacing) often produce fibrocartilage, or hyaline-appearing repair that is not sustained over time (Henche 1967, Ligament and Articular Cartilage Injuries. Springer-Verlag, New York, NY, pp. 157–164; Insall 1974, Clin. Orthop. 101: 61–67; Mitchell and Shepard 1976, J. Bone Joint Surg. [Am.] 58: 230–233; O’Driscoll et al. 1986, J. Bone Joint Surg. [Am.] 68: 1017–1035; 1989, Trans. Orthop. Res. Soc. 14: 145; Kim et al. 1991, J. Bone Joint Surg. [Am.] 73: 1301–1315). Autologous chondrocyte transplantation, although promising, requires two surgeries, has site-dependent and patient age limitations, and has unknown long-term donor site morbidity (Brittberg et al. 1994, N Engl. J. Med. 331: 889–895; Minas 2003, Orthopedics 26: 945–947; Peterson et al. 2003, J. Bone Joint Surg. Am. 85-A(Suppl. 2): S17–S24). Osteochondral allografts remain a widely used method of articular resurfacing to delay arthritic progression. The present study compared the histological response to four types of osteochondral implants in a rabbit model: autograft, frozen, freeze-dried, and fresh implants. Specimens implanted in the femoral groove were harvested at 6 and 12 weeks. Results showed similar restoration of the joint surface regardless of implant type, with a trend toward better repair at the later timepoint. As has been observed in other studies (Frenkel et al. 1997, J. Bone Joint Surg. 79B: 281–286; Toolan et al. 1998, J. Biomed. Mater. Res. 41: 244–250), each group in this study had at least one specimen in which a healthy-appearing surface on the implant was not well-integrated with host tissues. Although the differences were not statistically significant, freeze-dried implants at both timepoints had the best histological scores. The osteochondral grafts tested successfully restored the gross joint surface and congruity. At 12 weeks, no significant differences were observed between the various allografts and autologous osteochondral grafts.     

石膏固定和外固定支架在老年骨质疏松性桡骨远端骨折中的疗效比较

目的:分析石膏固定和外固定支架在治疗老年骨质疏松性桡骨远端骨折中的治疗效果,为临床治疗提供参考依据.方法:选取在我院诊治的93例老年骨质疏松性桡骨远端骨折患者作为研究对象,根据治疗方法不同分为石膏固定组和外固定支架组,并采用Jakim评分系统对两组患者腕关节功能进行评价.结果:术后6个月,石膏固定组主观指标评分为(26.7±2.2)分,支架组为(22.3±2.6)分,经t检验,差异有统计学意义,P＜0.05;石膏固定组优良率为83.3％,支架组为86.3％,经卡方检验,差异无统计学意义,P＞0.05.结论:手法复位石膏固定固定和闭合复位外固定支架固定治疗老年骨质疏松性桡骨远端骨折均有较好的治疗效果,石膏固定疗法更易被老年患者接受.     

Lymphatic Vessels Are Essential for the Removal of Cholesterol from Peripheral Tissues by SR-BI-Mediated Transport of HDL

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Genetic Analysis Identifies DDR2 as a Novel Gene Affecting Bone Mineral Density and Osteoporotic Fractures in Chinese Population

DDR2 gene, playing an essential role in regulating osteoblast differentiation and chondrocyte maturation, may influence bone mineral density (BMD) and osteoporosis, but the genetic variations actually leading to the association remain to be elucidated. Therefore, the aim of this study was to investigate whether the genetic variants in DDR2 are associated with BMD and fracture risk. This study was performed in three samples from two ethnicities, including 1,300 Chinese Han subjects, 700 Chinese Han subjects (350 with osteoporotic hip fractures and 350 healthy controls) and 2,286 US white subjects. Twenty-eight SNPs in DDR2 were genotyped and tested for associations with hip BMD and fractures. We identified 3 SNPs in DDR2 significantly associated with hip BMD in the Chinese population after multiple testing adjustments, which were rs7521233 (P = 1.06×10⁻⁴, β: −0.018 for allele C), rs7553831 (P = 1.30×10⁻⁴, β: −0.018 for allele T), and rs6697469 (P = 1.59×10⁻³, β: −0.015 for allele C), separately. These three SNPs were in high linkage disequilibrium. Haplotype analyses detected two significantly associated haplotypes, including one haplotype in block 2 (P = 9.54×10⁻⁴, β: −0.016) where these three SNPs located. SNP rs6697469 was also associated with hip fractures (P = 0.043, OR: 1.42) in the Chinese population. The effect on fracture risk was consistent with its association with lower BMD. However, in the white population, we didn’t observe significant associations with hip BMD. eQTL analyses revealed that SNPs associated with BMD also affected DDR2 mRNA expression levels in Chinese. Our findings, together with the prior biological evidence, suggest that DDR2 could be a new candidate for osteoporosis in Chinese population. Our results also reveal an ethnic difference, which highlights the need for further genetic studies in each ethnic group.     

大鼠代膀胱模型的建立

目的建立用于肠黏膜处理研究的大鼠代膀胱模型。方法雌性SD大鼠2组,实验组以4cm末段小肠重新构建大鼠膀胱,对照组行假手术。术后1月测量代膀胱容量,代膀胱内黏液残留量,观察代膀胱黏膜对水、电解质的吸收、分泌功能等。结果术后1月,实验组大鼠膀胱容量增加（P〈0．01）;黏液残留量：0．907±0．193g;代膀胱黏膜对水、K^＋、NH4^＋表现为吸收,对Na^＋、Cl^-、HCO3^-表现为分泌。结论此模型适用于肠黏膜处理的研究。     

Evaluation of a Prednisolone Acetate-Loaded Subconjunctival Implant for the Treatment of Recurrent Uveitis in a Rabbit Model

Aim

To assess the efficacy of a biodegradable, prednisolone acetate implant in a rabbit uveitis model.

Methods

Randomized, controlled study of biodegradable microfilms preloaded with prednisolone acetate (PA) in a rabbit uveitis model. Experimental uveitis was induced by unilateral intravitreal injection of Mycobacterium tuberculosis H37Ra antigen (50 ug; 1 ug/uL) in preimmunized rabbits. PA-loaded poly[d,l-lactide-co-ε-caprolactone] (PLC) microfilms (n = 10) and blank microfilms (n = 6) were implanted subconjunctivally. An estimate of PA release in vivo was calculated from measured residual PA amounts in microfilms after the rabbits were sacrificed. The eyes were clinically monitored for ocular inflammation for 28 days. Histopathological examination of the enucleated eyes was performed at the end of the study period.

Results

In vitro studies revealed that sandwich PA-loaded microfilm formulations exhibited higher release kinetic compared to homogenous PA-loaded microfilms. The 60–40–60% microfilm released an average of 0.034 mg/day of PA over the period of 60 days in vitro; and we found that approximately 0.12 mg/day PA was released in vivo. Animals implanted with the PA-loaded microfilms exhibited significantly lowered median inflammatory scores when compared against the control group in this model for recurrent uveitis (P<0.001). The implants were clinically well tolerated by all the animals. Histology results showed no significant scarring or inflammation around the PA-loaded microfilms.

Conclusion

Our pilot study demonstrated that a subconjunctival PA-loaded implant is effective in suppressing inflammation in the rabbit model of uveitis, by providing therapeutic levels of PA that attenuated the inflammatory response even after a rechallenge. Longer term studies are now needed to establish the therapeutic potential of such a delivery system for treatment of ocular inflammation.     

大鼠运动性疲劳模型的建立

目的建立大鼠运动疲劳模型,观察运动疲劳对大鼠各项生理、生化指标的影响。方法20只大鼠随机分为正常对照组和运动疲劳模型组,运动疲劳模型组大鼠每日按照方案进行锻炼。实验结束后大鼠检测相关指标：血清MDA含量和红细胞SOD活性,肝脏与骨骼肌MDA含量、SOD活性,骨骼肌线粒体游离钙离子含量,骨骼肌线粒体膜电位,下丘脑神经递质。电镜观察骨骼肌线粒体细微结构。结果运动疲劳模型组大鼠造模2周以后其血清、肝和骨骼肌MDA含量均有显著升高,红细胞和骨骼肌SOD活性均有显著降低,骨骼肌线粒体膜电位显著性降低,骨骼肌线粒体游离Ca2＋含量有显著性降低,下丘脑GABA、5-HT含量有显著升高,下丘脑DA、ACh含量有显著性下降,电镜观察显示骨骼肌超微结构改变并以线粒体改变较为明显。结论大鼠跑台运动2周可造成运动疲劳模型,并造成大鼠骨骼肌线粒体损伤。     

Molecular Profiling of the Lateral Habenula in a Rat Model of Depression

Objective

This study systematically investigated the effect of chronic mild stress and response to antidepressant treatment in the lateral habenula at the whole genome level.

Methods

Rat whole genome expression chips (Affymetrix) were used to detect gene expression regulations in the lateral habenula of rats subjected to chronic mild stress (mild stressors exchanged twice a day for 8 weeks). Some rats received antidepressant treatment during fifth to eights week of CMS. The lateral habenula gene expression profile was studied through the gene ontology and signal pathway analyses using bioinformatics. Real-time quantitative polymerase chain reaction (RT-PCR) was used to verify the microarray results and determine the expression of the Fcrla, Eif3k, Sec3l1, Ubr5, Abca8a, Ankrd49, Cyp2j10, Frs3, Syn2, and Znf503 genes in the lateral habenula tissue.

Results

In particular we found that stress and antidepressant treatment affected intracellular cascades like growth factor receptor signaling, G-protein-coupled receptor signaling, and Wnt signaling – processes involved in the neuroplastic changes observed during the progression of depression and antidepressant treatment.

Conclusion

The present study suggests an important role of the lateral habenula in the development of depression-like conditions and correlates to previous studies demonstrating a significant role of the lateral habenula in depressive-like conditions and antidepressant treatment.     

Bacterial Enrichment at the Gas-Water Interface of a Laboratory Apparatus

The gas-water interface (GWI) is likely to have important effects on bacterial adsorption and transport in unsaturated porous media. A glass apparatus that isolated GWIs in ports above a flowthrough suspension of a groundwater bacterial isolate was used to represent unsaturated porous media. The surface microlayer was collected by placing a polycarbonate filter on the GWI. The filter was stained, and the bacteria were enumerated by direct count. The significance of five independent variables on the surface density of cells (s, in cells per square millimeter) was determined by nonlinear multiple regression. Three of the variables were shown to be significant: surfactant concentration (d), time (t), and bulk bacterial concentration (B). The surface density decreased with increasing d and increased with increasing t and B. When surfactant was absent, the GWI became highly enriched in bacteria. For example, when d = 0, 48 h < t < 72 h, and 5,000 cells mm(sup-3) < B < 10,000 cells mm(sup-3), s averaged 3.0 x 10(sup4) cells mm(sup-2). This surface density occupied about 6.0% of the GWI, and the surface microlayer concentration of cells was 190 times the bulk concentration. The other two variables: pH (p) and ionic strength (I) were shown to be insignificant. The strong effect of d and the lack of effect of I and p support the hypothesis that hydrophobic interaction dominates bacterial adsorption to the GWI.     

大鼠再生障碍性贫血模型制备

目的诱导稳定而可逆的大鼠再生障碍性贫血模型。方法模型A组造模第1天以直线加速器剂量率为240 cGy/min,SSD=100 cm,全身照射1.2 min,分别于第4、6、8天腹腔注射环磷酰胺35 mg/kg和氯霉素43.75 mg/kg,共3次;模型B组造模第1天以直线加速器剂量率300 cGy/min,SSD=100 cm,全身照射1.2 min。分别于第4、5、6天腹腔注射环磷酰胺35 mg/kg和氯霉素43.75 mg/kg,共3次。对照组造模第1天以假照射。于造模9、12、15 d后进行网织红细胞计数、外周血象检查、骨髓活检。结果造模第9天与对照组比较,A组、B组的白细胞（WBC）、红细胞（RBC）、血小板（PLT）、血红蛋白（HGB）、网织红细胞计数（RET）均明显降低,差异有显著性（P〈0.05）。于造模第15天,A组RBC、HGB值继续下降,WBC、PLT、RET值回升,与对照组比较降低,差异有显著性（P〈0.05）;B组WBC、RBC、HGB、PLT值有显著回升,与对照组比较降低,差异有显著性（P〈0.05）;RET值与对照组比较升高,差异有显著性（P〈0.05）。结论模型A组具有复制周期短,成功率高、重复性好,死亡率低等优点。适合用于治疗药物研究的实验。     

Decalcification at the Mantle-Shell Interface in Molluscs

Decalcification at the mantle-shell interface in Mercenariatnercenaria was studied through the changes in the chemicalcomposition of the extrapallial fluid, and by the measurementof Ca⁴⁵-deposition and solution. Measurements of O₂-tensiondemonstrated that the clam was anaerobic soon after the valveswere closed. Measurements of calcium, carbon dioxide, and hydrogenion concentration showed that all of these components of theextrapallial fluid increase with increasing time of closure.These measurements, and measurements of calcium and succinicacid in the tissues and fluids of the clam, indicated thatsuccinicacid produced by the anaerobic metabolism of the clam was neutralizedby the dissolution of previously deposited shell.     

Conformational States of Melittin at a Bilayer Interface

The distribution of peptide conformations in the membrane interface is central to partitioning energetics. Molecular-dynamics simulations enable characterization of in-membrane structural dynamics. Here, we describe melittin partitioning into dioleoylphosphatidylcholine lipids using CHARMM and OPLS force fields. Although the OPLS simulation failed to reproduce experimental results, the CHARMM simulation reported was consistent with experiments. The CHARMM simulation showed melittin to be represented by a narrow distribution of folding states in the membrane interface.Unstructured peptides fold into the membrane interface because partitioned hydrogen-bonded peptide bonds are energetically favorable compared to free peptide bonds (1–3). This folding process is central to the mechanisms of antimicrobial and cell-penetrating peptides, as well as to lipid interactions and stabilities of larger membrane proteins (4). The energetics of peptide partitioning into membrane interfaces can be described by a thermodynamic cycle (Fig. 1). State A is a theoretical state representing the fully unfolded peptide in water, B is the unfolded peptide in the membrane interface, C is the peptide in water, and D is the folded peptide in the membrane. The population of peptides in solution (State C) is best described as an ensemble of folded and unfolded conformations, whereas the population of peptides in State D generally is assumed to have a single, well-defined helicity, as shown in Fig. 1 A (5). Given that, in principle, folding in solution and in the membrane interface should follow the same basic rules, peptides in state D could reasonably be assumed to also be an ensemble. A fundamental question (5) is therefore whether peptides in state D can be correctly described as having a single helicity. Because differentiating an ensemble of conformations and a single conformation may be an impossible experimental task (5), molecular-dynamics (MD) simulations provide a unique high-resolution view of the phenomenon.Open in a separate windowFigure 1Thermodynamic cycles for peptide partitioning into a membrane interface. States A and B correspond to the fully unfolded peptide in solution and membrane interface, respectively. The folded peptide in solution is best described as an ensemble of unfolded and folded conformations (State C). State D is generally assumed to be one of peptides with a narrow range of conformations, but the state could actually be an ensemble of states as in the case of State C.Melittin is a 26-residue, amphipathic peptide that partitions strongly into membrane interfaces and therefore has become a model system for describing folding energetics (3,6–8). Here, we describe the structural dynamics of melittin in a dioleoylphosphatidylcholine (DOPC) bilayer by means of two extensive MD simulations using two different force fields.We extended a 12-ns equilibrated melittin-DOPC system (9) by 17 μs using the Anton specialized hardware (10) with the CHARMM22/36 protein/lipid force field and CMAP correction (11,12) (see Fig. S1 and Fig. S2 in the Supporting Material). To explore force-field effects, a similar system was simulated for 2 μs using the OPLS force field (13) (see Methods in the Supporting Material). In agreement with x-ray diffraction measurements on melittin in DOPC multilayers (14), melittin partitioned spontaneously into the lipid headgroups at a position below the phosphate groups at similar depth as glycerol/carbonyl groups (Fig. 2).Open in a separate windowFigure 2Melittin partitioned into the polar headgroup region of the lipid bilayer. (A) Snapshot of the simulation cell showing two melittin molecules (MLT1 and MLT2, in yellow) at the lipid-water interface. (B) Density cross-section of the simulation cell extracted from the 17-μs simulation. The peptides are typically located below the lipid phosphate (PO4) groups, in a similar depth as the glycerol/carbonyl (G/C) groups.To describe the secondary structure for each residue, we defined helicity by backbone dihedral angles (φ, ψ) within 30° from the ideal α-helical values (–57°, –47°). The per-residue helicity in the CHARMM simulation displays excellent agreement with amide exchange rates from NMR measurements that show a proline residue to separate two helical segments, which are unfolded below Ala⁵ and above Arg²² (15) (Fig. 3 A). In contrast, the OPLS simulation failed to reproduce the per-residue helicity except for a short central segment (see Fig. S3).Open in a separate windowFigure 3Helicity and conformational distribution of melittin as determined via MD simulation. (A) Helicity per residue for MLT1 and MLT2. (B) Corresponding evolution of the helicity. (C) Conformational distributions over the entire 17-μs simulation.Circular dichroism experiments typically report an average helicity of ∼70% for melittin at membrane interfaces (3,6,16,17), but other methods yield average helicities as high as 85% (15,18). Our CHARMM simulations are generally consistent with the experimental results, especially amide-exchange measurements (15); melittin helicity averaged to 78% for MLT1, whereas MLT2 transitioned from 75% to 89% helicity at t ≈ 8 μs, with an overall average helicity of 82% (Fig. 3 B). However, in the OPLS simulation, melittin steadily unfolds over the first 1.3 μs, after which the peptide remains only partly folded, with an average helicity of 33% (see Fig. S3). Similar force-field-related differences in peptide helicity were recently reported, albeit at shorter timescales (19). Although suitable NMR data are not presently available, we have computed NMR quadrupolar splittings for future reference (see Fig. S4).To answer the question asked in this article—whether the conformational space of folded melittin in the membrane interface can be described by a narrow distribution—the helicity distributions for the equilibrated trajectories are shown in Fig. 3 C. Whereas MLT1 in the CHARMM simulation produces a single, narrow distribution of the helicity, MLT2 has a bimodal distribution as a consequence of the folding event at t ≈ 8 μs (Fig. 3 C). We note that CHARMM force fields have a propensity for helix-formation and this transition might therefore be an artifact. We performed a cluster analysis to describe the structure of the peptide in the membrane interface. The four most populated conformations in the CHARMM simulation are shown in Fig. 4. The dominant conformation for both peptides was a helix kinked at G12 and unfolded at the last 5–6 residues of the C-terminus. The folding transition of MLT2 into a complete helix is visible by the 48% occupancy of a fully folded helix.Open in a separate windowFigure 4Conformational clusters of the two melittin peptides (MLT1 and MLT2) from the 17-μs CHARMM simulation in DOPC. Clustering is based on Cα-RMSD with a cutoff criterion of 2 Å.We conclude that the general assumption when calculating folding energetics holds: Folded melittin partitioned into membrane interfaces can be described by a narrow distribution of conformations. Furthermore, extended (several microsecond) simulations are needed to differentiate force-field effects. Although the CHARMM and OPLS simulations would seem to agree for the first few hundred nanoseconds, the structural conclusions differ drastically with longer trajectories, with CHARMM parameters being more consistent with experiments. However, as implied by the difference in substate distributions between MLT1 and MLT2, 17 μs might not be sufficient to observe the fully equilibrated partitioning process. The abrupt change in MLT2 might indicate that the helicity will increase to greater than experimentally observed in a sufficiently long simulation. On the other hand, it could be nothing more than a transient fluctuation. Increased sampling will provide further indicators of convergence of the helix partitioning process.     

大鼠动脉粥样硬化动物模型的建立和评价

目的利用免疫损伤和高脂喂养结合的方法建立大鼠动脉粥样硬化（atherosclerosis,AS）动物模型。方法5周龄Wistar大鼠腹腔注射卵清白蛋白和尾静脉注射牛血清白蛋白佐以灌喂维生素D3,高脂饲料喂养大鼠,FeSO4加入到饮水中。检测大鼠不同时间的血脂水平、血液生化指标和病理变化。结果（1）AS模型组的TC、HDL、LDL显著高于正常对照组（6.1±2.52比1.3±0.10;2.46±1.01比1.02±0.13;3.76±1.67比0.52±0.063;P〈0.05）。（2）模型组的C反应蛋白（CRP）、心肌激酶（CK）、心肌激酶同工酶（CK-Mb）显著高于正常对照组（4.99±2.26比0.183±0.160;996.3±82.8比293.8±167.1;669.5±128.1比177.5±86.5;P〈0.05）。（3）采用HE染色发现模型组大鼠的主动脉出现斑块的沉积,而正常大鼠无病变的产生。结论该方法能够诱导大鼠产生高血脂症状,随着时间的延长心肌发生损伤,同时出现炎症症状,并在动脉壁上形成斑块。     

Bioflavonoid Rescue of Ascorbate at a Membrane Interface

In aqueous solution, ascorbate potently prevents bleaching of cytochrome c on exposure to excess H₂O₂ or t-butyl hydroperoxide. Ascorbate failed to protect cytochrome c in the presence of liposomes of mitochondrial membranelike composition. Like the redox mediator N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD), however, the bioflavonoids epicatechin and quercetin restored the protection afforded by ascorbate in the presence of liposomes and gave further protection. The quercetin glycoside, rutin, was much less effective, as was the vitamin E analog Trolox. In the presence of liposomes, quercetin alone was relatively ineffective, but cooperated with ascorbate to extend protection synergistically. The results bear specific implications in antioxidant protection of cytochrome c and in moderation of its hydroperoxidase activities in biological membranes. The data also reveal a situation where ascorbate is without effect except in the presence of a bioflavonoid, and substantiate a possibly vital role for certain bioflavonoids in mediating electron transfer from ascorbate into a hydrophobic environment.     

光学相干层析术高分辨率活体成像泼尼松龙诱导的骨质疏松斑马鱼模型

本研究利用光学相干层析术OCT对泼尼松龙诱导的斑马鱼骨质疏松模型进行活体成像,并结合电镜能谱技术定量分析斑马鱼模型骨质的钙磷元素含量及分布情况,共同探讨OCT方法在基于斑马鱼模型开展的骨质疏松研究中的使用价值。选取40条3月龄野生型斑马鱼暴露于50μmol/L泼尼松龙溶液和含0. 5%DMSO的溶液中(对照组),28. 5℃下培养,分别于第5、10、20天取出浸药组和对照组进行OCT活体成像,比较两者光散射特征。在每个时间点的成像之后,将浸药组的5条斑马鱼处死,然后取颅骨进行元素含量电镜扫描能谱分析。本研究利用50μmol/L泼尼松龙溶液培养斑马鱼至第20天,成功构建了斑马鱼骨质疏松模型。与对照组相比,模型组活体OCT成像显示骨组织光散射减弱,光子量明显减少,呈不均匀分布。能谱元素检查结果说明颅骨内所含钙、磷比例明显下降,证实骨质疏松发生,骨量减少。OCT成像方法在对斑马鱼骨质疏松模型进行活体、实时、无创等研究方面具有重要价值,本试验也为骨质疏松疾病的研究和药物筛选等方面提供了新的有效的方法。