Activation of HIFa Pathway in Mature Osteoblasts Disrupts the Integrity of the Osteocyte/Canalicular Network

The hypoxia-inducible factors (HIFs), HIF-1α and HIF-2α, are the central mediators of the homeostatic response that enables cells to survive and differentiate in low-oxygen conditions. Previous studies indicated that disruption of the von Hippel-Lindau gene (Vhl) coincides with the activation of HIFα signaling. Here we show that inactivation of Vhl in mature osteoblasts/osteocytes induces their apoptosis and disrupts the cell/canalicular network. VHL-deficient (ΔVHL) mice exhibited a significantly increased cortical bone area resulting from enhanced proliferation and osteogenic differentiation of the bone marrow stromal cells (BMSCs) by inducing the expression of β-catenin in the BMSC. Our data suggest that the VHL/HIFα pathway in mature osteoblasts/osteocytes plays a critical role in the bone cell/canalicular network and that the changes of osteocyte morphology/function and cell/canalicular network may unleash the bone formation, The underlying mechanism of which was the accumulation of β-catenin in the osteoblasts/osteoprogenitors of the bone marrow.     

Liquid-Solid Phase-Inversion PLGA Implant for the Treatment of Residual Tumor Tissue after HIFU Ablation

BackgroundHIFU has been shown to be a more suitable alternative for the treatment of primary solid tumors and metastatic diseases than other focal heat ablation techniques due to its noninvasive and extracorporeal nature. However, similar to other focal heat ablation techniques, HIFU is still in need of refinements due to tumor recurrence.MethodsIn this work, we investigated the effectiveness of an adjunct treatment regimen using doxorubicin (DOX)-loaded, injectable, in situ-forming, and phase-inverting PLGA as the second line of defense after HIFU ablation to destroy detrimental residual tumors and to prevent tumor recurrence. All of the statistical analyses were performed using the Statistical Package for the Social Sciences 18.0(SPSS, Inc., Chicago, IL, USA), and p< 0.05 was considered statistically significant. All of the results are presented as the means ± STDEV (standard deviation). For multiple comparisons, ANOVA (differences in tumor volumes, growth rates, apoptosis, proliferation indexes, and Bcl-2 and Bax protein levels) was used when the data were normally distributed with homogenous variance, and rank sum tests were used otherwise. Once significant differences were detected, Student-t tests were used for comparisons between two groups.ResultsOur results revealed that DOX diffused beyond the ablated tissue regions and entered tumor cells that were not affected by the HIFU ablation. Our results also show that HIFU in concert with DOX-loaded PLGA led to a significantly higher rate of tumor cell apoptosis and a lower rate of tumor cell proliferation in the areas beyond the HIFU-ablated tissues and consequently caused significant tumor volume shrinkage (tumor volumes:0.26±0.1,1.09±0.76, and 1.42±0.9cm³ for treatment, sham, and no treatment control, respectively).ConclusionsFrom these results, we concluded that the intralesional injection of DOX-loaded PLGA after HIFU ablation is significantly more effective than HIFU alone for the treatment of solid tumors.     

Evaluation of the Microcirculation in a Rabbit Hemorrhagic Shock Model Using Laser Doppler Imaging

The aim of this study is to evaluate the feasibility of Laser Doppler imaging (LDI) for noninvasive and dynamic assessment of hemorrhagic shock in a rabbit model. A rabbit model of hemorrhagic shock was generated and LDI of the microcirculation in the rabbit ears was performed before and at 0, 30, 60, and 90 min after hemorrhage. The CCD (Charge Coupled Device) image of the ears, the mean arterial pressure (MAP) and the heart rate (HR) were monitored. The mean LDI flux was calculated. The HR of rabbits was significantly (p < 0.05) elevated and the MAP was decreased after hemorrhage, compared to the pre-hemorrhage level. Within the initial 30 min after hemorrhage, the perfusion flux lineally dropped down. In contrast, the MAP values did not differ significantly between the time points of 0 and 30 after hemorrhage (p > 0.05). Both the flux numbers and the red-to-blue color changes on LDI imaging showed the reduction of the microcirculation. LDI imaging is a noninvasive and non-contact approach to evaluate the microcirculation and may offer benefits in the diagnosis and treatment of hemorrhage shock. Further studies are needed to confirm its effectiveness in clinical practice.     

Eriophyoid mites (Acari,Eriophyoidea) associated with tea plants,with descriptions of a new genus and two new species

A new genus and two new species of mites in the family Eriophyidae, Theaphyes rapaneae gen. n. and sp. n. which is found on the type host Rapanea neriifolia (Sieb. et Zucc.) Mez (Myrsinaceae) and Paracaphyllisa theacea sp. n., are described and illustrated. They are vagrants on the tea plant Camellia sinensis (L.) Kuntze and no apparent symptoms were detected. A key to the eriophyoid mites including thirteen species associated with tea plants all over the world is provided.     

黑龙江省一株红小豆锈病病原菌鉴定

【目的】为明确发生在黑龙江省大庆市红小豆田中的锈病病原物的分类地位。【方法】从大庆市采集红小豆锈病标样,采用单孢子堆分离法获得一株红小豆锈病菌纯培养物ZXL01。采用观测夏孢子芽孔数目、位置和冬孢子壁厚度等形态学特征结合ITS序列分析的方法,对其进行鉴定。【结果】ZXL01夏孢子发芽孔多为2个,位于孢子赤道部位较远之处,冬孢子壁厚度为2.9μm-3.3μm。在基于r DNA-ITS序列构建的系统发育树中,ZXL01菌株与两株豇豆单胞锈菌(Uromyces vignae)的参比菌株(Gen Bank登录号:AB115718和AB115731)在自举值99%相聚一群。用豇豆单胞锈菌的特异性引物UV-ITSF/R进行检测,ZXL01菌株可扩增出500 bp左右的特征片段。【结论】黑龙江省大庆市红小豆锈病病原菌ZXL01菌株为豇豆单胞锈菌,ZXL01菌株的Gen Bank登录号是KM461700。     

Alternative Transposition Generates New Chimeric Genes and Segmental Duplications at the Maize p1 Locus

The maize Ac/Ds transposon family was the first transposable element system identified and characterized by Barbara McClintock. Ac/Ds transposons belong to the hAT family of class II DNA transposons. We and others have shown that Ac/Ds elements can undergo a process of alternative transposition in which the Ac/Ds transposase acts on the termini of two separate, nearby transposons. Because these termini are present in different elements, alternative transposition can generate a variety of genome alterations such as inversions, duplications, deletions, and translocations. Moreover, Ac/Ds elements transpose preferentially into genic regions, suggesting that structural changes arising from alternative transposition may potentially generate chimeric genes at the rearrangement breakpoints. Here we identified and characterized 11 independent cases of gene fusion induced by Ac alternative transposition. In each case, a functional chimeric gene was created by fusion of two linked, paralogous genes; moreover, each event was associated with duplication of the ∼70-kb segment located between the two paralogs. An extant gene in the maize B73 genome that contains an internal duplication apparently generated by an alternative transposition event was also identified. Our study demonstrates that alternative transposition-induced duplications may be a source for spontaneous creation of diverse genome structures and novel genes in maize.     

Long-chain Acylcarnitines Reduce Lung Function by Inhibiting Pulmonary Surfactant

The role of mitochondrial energy metabolism in maintaining lung function is not understood. We previously observed reduced lung function in mice lacking the fatty acid oxidation enzyme long-chain acyl-CoA dehydrogenase (LCAD). Here, we demonstrate that long-chain acylcarnitines, a class of lipids secreted by mitochondria when metabolism is inhibited, accumulate at the air-fluid interface in LCAD^−/− lungs. Acylcarnitine accumulation is exacerbated by stress such as influenza infection or by dietary supplementation with l-carnitine. Long-chain acylcarnitines co-localize with pulmonary surfactant, a unique film of phospholipids and proteins that reduces surface tension and prevents alveolar collapse during breathing. In vitro, the long-chain species palmitoylcarnitine directly inhibits the surface adsorption of pulmonary surfactant as well as its ability to reduce surface tension. Treatment of LCAD^−/− mice with mildronate, a drug that inhibits carnitine synthesis, eliminates acylcarnitines and improves lung function. Finally, acylcarnitines are detectable in normal human lavage fluid. Thus, long-chain acylcarnitines may represent a risk factor for lung injury in humans with dysfunctional fatty acid oxidation.