Chromosome and gene copy number variation allow major structural change between species and strains of Leishmania

Leishmania parasites cause a spectrum of clinical pathology in humans ranging from disfiguring cutaneous lesions to fatal visceral leishmaniasis. We have generated a reference genome for Leishmania mexicana and refined the reference genomes for Leishmania major, Leishmania infantum, and Leishmania braziliensis. This has allowed the identification of a remarkably low number of genes or paralog groups (2, 14, 19, and 67, respectively) unique to one species. These were found to be conserved in additional isolates of the same species. We have predicted allelic variation and find that in these isolates, L. major and L. infantum have a surprisingly low number of predicted heterozygous SNPs compared with L. braziliensis and L. mexicana. We used short read coverage to infer ploidy and gene copy numbers, identifying large copy number variations between species, with 200 tandem gene arrays in L. major and 132 in L. mexicana. Chromosome copy number also varied significantly between species, with nine supernumerary chromosomes in L. infantum, four in L. mexicana, two in L. braziliensis, and one in L. major. A significant bias against gene arrays on supernumerary chromosomes was shown to exist, indicating that duplication events occur more frequently on disomic chromosomes. Taken together, our data demonstrate that there is little variation in unique gene content across Leishmania species, but large-scale genetic heterogeneity can result through gene amplification on disomic chromosomes and variation in chromosome number. Increased gene copy number due to chromosome amplification may contribute to alterations in gene expression in response to environmental conditions in the host, providing a genetic basis for disease tropism.     

Possible Relation of Hemin-Induced HO-1 Expression to the Upregulation of VEGF and BDNF mRNA Levels in Rat C6 Glioma Cells

Glial cells are generally considered to contribute to retaining the integrity of neural function through the protection of neuronal cells against neurodegenerative insults and also expected to play a potential role in the protection of cerebrovascular systems from various toxic insults of hemorrhaged blood, thus proposing a possible implication of glial cells in the recovery of brain function from the damage caused by cerebral hemorrhage. Based on this hypothetical idea, the direct effect of hemin on the expression of genes encoding heme oxygenase-1 (HO-1), vascular endothelial growth factor (VEGF), and brain-derived neurotrophic factor (BDNF) in glial cells was examined using rat C6 glioma cells as an in vitro model system. Hemin elevated both HO-1 and VEGF mRNA levels in the glioma cells at the concentration causing no critical damage to the cells, and the elevation of BDNF mRNA levels was also observed by exposing the cells to hemin under the same conditions. Furthermore, the elevation of VEGF and BDNF mRNA levels induced by hemin was blocked by pretreatment of the cells with the agents inhibiting not only HO-1 gene expression but also its enzymatic activity. These pharmacological studies indicate that hemin can induce the enhancement of VEGF and BDNF gene expression probably through the mechanism mediated by HO-1 activity in the glioma cells, proposing the possibility that glial cells are capable of contributing to the recovery of brain function from the damage caused by cerebral hemorrhage through the production of neurogenic and angiogenic factors.     

Therapeutic Potential of Human Adipose Stem Cells in a Rat Myocardial Infarction Model

Purpose

Stem cell transplantation is expected to have good effects in the treatment of myocardial infarction (MI). We tested the effect of the transplantation of human adipose-derived cells (ASCs) in Sprague-Dawley (SD) rats with myocardial infarctions.

Materials and Methods

ASCs were isolated from the waste of elective abdominal surgery. The MI model was set up in SD rats by permanent ligation of the left anterior descending coronary artery. One week after MI, either 1 × 10⁶ ASCs or an equal volume of phosphate-buffered saline (PBS) was injected into the infarct zone. Cardiac function was assessed by echocardiography, 1 day, 1 week, 2 weeks, and 4 weeks after treatment. Four weeks after transplantation, immunohistochemistry was performed.

Results

Left ventricular function, including fractional shortening (FS), and ejection fraction (EF) showed a significant improvement in the ASCs transplantation group compared to the PBS group 4 weeks after treatment (p < 0.05). The anterior wall thickness of the left ventricle was significantly thicker in the ASCs transplantation group compared to the PBS group (p < 0.01). Multiple troponin T staining, and irregular, small amounts of connexin 43 expression also was observed in the ASCs transplantation group. Infarcted myocardium showed higher capillary density in the ASCs transplantation group than in the PBS injected group (p < 0.01).

Conclusion

This study provides encouraging evidence that transplantation of ASCs can improve cardiac function of infarct myocardium in rat models with a limitation of cardiac remodeling, improved wall thickness, and increased neovascularization.     

Clinical benefit of low molecular weight heparin for ST-segment elevation myocardial infarction patients undergoing primary percutaneous coronary intervention with glycoprotein IIb/IIIa inhibitor

The efficacy of low molecular weight heparin (LMWH) with low dose unfractionated heparin (UFH) during percutaneous coronary intervention (PCI) with or without glycoprotein (Gp) IIb/IIIa inhibitor compared to UFH with or without Gp IIb/IIIa inhibitor has not been elucidated. Between October 2005 and July 2007, 2,535 patients with ST elevation acute myocardial infarction (STEMI) undergoing PCI in the Korean Acute Myocardial Infarction Registry (KAMIR) were assigned to either of two groups: a group with Gp IIb/IIIa inhibitor (n=476) or a group without Gp IIb/IIIa inhibitor (n=2,059). These groups were further subdivided according to the use of LMWH with low dose UFH (n=219) or UFH alone (n=257). The primary end points were cardiac death or myocardial infarction during the 30 days after the registration. The primary end point occurred in 4.1% (9/219) of patients managed with LMWH during PCI and Gp IIb/IIIa inhibitor and 10.8% (28/257) of patients managed with UFH and Gp IIb/IIIa inhibitor (odds ratio [OR], 0.290; 95% confidence interval [CI], 0.132-0.634; P=0.006). Thrombolysis In Myocardial Infarction (TIMI) with major bleeding was observed in LMHW and UFH with Gp IIb/IIIa inhibitor (1/219 [0.5%] vs 1/257 [0.4%], P=1.00). For patients with STEMI managed with a primary PCI and Gp IIb/IIIa inhibitor, LMWH is more beneficial than UFH.     

Oestrogen up‐regulates interleukin‐21 production by CD4+ T lymphocytes in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease in which abnormal immune responses are mediated by tissue‐binding autoantibodies and immune complex deposition. Because most SLE patients are women of child‐bearing age, oestrogen has been suggested to play an important role in SLE pathogenesis. One proposed role is to induce B‐cell activation, culminating in increased autoantibody production. Interleukin‐21 (IL‐21) has been shown to be crucial in the differentiation of activated B cells into plasma cells. We therefore hypothesized that oestrogen up‐regulates IL‐21 production and induces subsequent B‐cell activation in SLE patients. Peripheral blood was obtained from 22 SLE patients and 16 healthy controls. Expression levels of IL‐21 and its receptor in serum, peripheral blood mononuclear cells, and CD4⁺ T cells were higher in SLE patients than in healthy controls. Exposure of CD4⁺ T cells from SLE patients to 17β‐oestradiol led to a dose‐ and time‐dependent increase in IL‐21 expression, which was abolished in the presence of mitogen‐activated protein kinase (MAPK) (MAPK kinase, p38, Jun N‐terminal kinase) inhibitors. B cells from healthy controls showed increased antibody production when they were co‐cultured with oestrogen‐treated CD4⁺ T cells from SLE patients. Treatment with IL‐21 antibody abrogated the increased antibody production of the co‐culture systems. This study revealed the association between oestrogen and IL‐21 in SLE patients. Oestrogen up‐regulates IL‐21 expression of CD4⁺ T cells via MAPK‐dependent pathways in SLE patients, which in turn induces increased antibody production by B cells.     

IL-15 promotes osteoclastogenesis via the PLD pathway in rheumatoid arthritis

Osteoclastogenesis plays an important role in joint destruction in rheumatoid arthritis (RA). IL-15 is a pleiotropic proinflammatory cytokine that appears to help mediate the pathological bone loss. This study was undertaken to explore the signaling molecules essential for osteoclastogenesis mediated by IL-15 in rheumatoid synovial fibroblasts. Expression of phospholipase D1 (PLD1) and osteoclast-related gene expression in synovial tissues and their modulation by treatment with IL-15 and different inhibitors in synovial fibroblasts of RA patients were evaluated using immunohistochemistry and quantitative polymerase chain reaction. The levels of IL-15 in serum and synovial fluid were measured by ELISA. The effects of IL-15 and phosphatidic acid (PA) on osteoclast formation were evaluated in cocultures of rheumatoid synovial fibroblasts and peripheral blood monocytes or monocytes alone in the presence of M-CSF and RANKL. The levels of RANKL and PLD1 but not PLD2 were upregulated significantly by IL-15, and the RANKL level was significantly upregulated by PA in rheumatoid synovial fibroblasts. Blocking PA production with 1-butanol and siRNA against PLD1 significantly inhibited the IL-15-stimulated expression of RANKL and PLD1. IL-15 levels were significantly higher in serum and synovial fluid from patients with RA than in osteoarthritis patients and healthy controls. IL-15 and PA induced osteoclast formation through the mitogen-activated protein kinases (MAPKs) and NF-κB signaling pathways. Activation of PLD1 contributes to IL-15-mediated osteoclastogenesis via the MAPKs and NF-κB signaling pathways in rheumatoid synovial fibroblasts. Our data suggest that PLD1 might be an efficient therapeutic strategy for preventing bone destruction in rheumatoid arthritis.     

疾病感知问卷中文版对急性心肌梗死患者的适用性和信效度分析

目的:探讨修订的疾病感知问卷(IPQ-R)中文版在急性心肌梗死患者中的适用性,并分析其信效度。方法:按量表翻译程序将IPQ-R译成中文,方便选取118名急性ST段抬高的心肌梗死患者进行IPQ-R中文版的测量,同时运用综合性医院焦虑抑郁量表(HADS)初步评价情绪状态。选取32名患者于初评后1个月重复测量。结果:IPQ-R中文版内部一致性系数为0.66-0.92;1个月的重测信度略低,为0.35-0.61;与焦虑评分相关明显(r=0.049-0.384,P<0.05)。探索性因素分析提取了7个特征根大于1的因子,各条目负荷范围为0.42-0.88,累积贡献率为60.75%,能够合理解释问卷的结构。结论:IPQ-R中文版适用于急性心肌梗死患者,具有较好的信度和效度。     

膀胱癌组织P-gp,GST-π和TOPO-Ⅱ表达评估灌注化疗

目的：探讨膀胱癌的多药耐药性(MDR)，指导灌注化疗用药。方法：采用免疫组化法检测44例膀胱癌病理标本中P-糖蛋白(P-gp)、谷胱肽S转移酶(GST-π)和拓扑异构酶(TOPO—Ⅱ)的表达，评估肿瘤耐药谱。结果：①P-gp检测显示，54．5％的病例对阿毒索、丝裂毒索、长春新碱等抗生索类和生物碱类抗癌药高耐药。②GST-π检测显示仅34．1％的病例对顺铂、环磷酰胺等高耐药，而反有56．8％的病例对该类药无耐药或低度耐药。③TOPO-Ⅱ检测显示对阿霉索、柔红毒索、VP16等TOPO-Ⅱ抑制剂类抗癌药，仅13．6％的病例高度耐药，29．5％中度耐药。56．8％低度耐药。结论：检测膀胱癌MDR，了解多药耐药谱，可指导灌注化疗用药。     

Successful 18-h acellular extracorporeal perfusion and replantation of porcine limbs - Histology versus nerve stimulation

The current standard for composite tissue preservation is static cold storage (SCS) and is limited to 6 h until irreversible muscle damage occurs. Extracorporeal perfusion (ECP) is a promising technique for prolonged preservation, however, functional results have been scarcely researched. This article assessed neuromuscular function and compared results to histological alterations to predict muscle damage after ECP. Forelimbs of twelve Dutch landrace pigs were amputated and preserved by 4 h SCS at 4–6 °C (n = 6) or 18 h mid-thermic ECP with University of Wisconsin solution (n = 6). Limbs were replanted and observed for 12 h. Sham surgery was performed on contralateral forelimbs (n = 12). Histology analysis scored four subgroups representing different alterations (higher score equals more damage). Muscle contraction after median nerve stimulation was comparable between ECP, SCS, and sham limbs (P = 0.193). Histology scores were higher in ECP limbs compared to SCS limbs (4.8 vs. 1.5, P = 0.013). This was mainly based on more oedema in these limbs. In-vivo muscle contraction was well preserved after 18 h ECP compared to short SCS, although histology seemed inferior in this group. Histology, therefore, did not correlate to muscle function at 12 h after replantation. This leads to the question whether histology or neuromuscular function is the best predictor for transplant success.     

Quantitative and qualitative comparison of 1.5 and 3.0 tesla MRI in patients with chronic liver diseases

Purpose

To compare the quantitative and qualitative image quality intra‐individually, at 1.5 and 3.0 Tesla (T) in patients with chronic liver diseases.

Materials and Methods

The study group included 24 consecutive patients (17 males, 7 females; mean age ± standard deviation 56.5 ± 11.5) who had chronic liver diseases and underwent abdominal MRI for the liver evaluation at both 1.5 and 3.0T within a 4‐month period. All MRI studies were retrospectively evaluated quantitatively and qualitatively. Quantitative analysis was performed by measuring signal to noise ratio (SNR) on various abdominal organs. Qualitative analysis was performed by two reviewers to assess image quality, artifacts, and imaging findings of chronic liver diseases. Quantitative and qualitative analyses findings were compared between 1.5 and 3.0T using the paired Student t‐test and Wilcoxon signed rank test, respectively.

Results

The statistically significant increase in SNRs in various abdominal tissues ranged from 1.3‐ to 3.5‐fold at 3.0T compared to 1.5T. Three‐dimensional gradient echo (3D‐GE) sequences demonstrated significantly higher image quality at 3.0T (P < 0.01), whereas precontrast spoiled gradient echo (SGE) sequences demonstrated significantly higher image quality at 1.5T (P < 0.01). T2‐weighted sequences did not show any significant difference in image quality between 1.5 and 3.0T (P > 0.05).

Conclusion

The SNRs of various abdominal tissues demonstrated significant increases at 3.0T. The image quality of 3D‐GE sequences was higher at 3.0T, whereas the image quality of precontrast SGE sequences was higher at 1.5T. J. Magn. Reson. Imaging 2009;29:869–879. © 2009 Wiley‐Liss, Inc.