The growth and developmental of the myodural bridge and its associated structures in the human fetus.

Myodural bridge (MDB) is a dense connective tissue between suboccipital muscle and dura mater. However, there are few reports on the development and maturation of the human MDB. This study aims to explore the developmental relationship between suboccipital muscle and MDB. 30 head and neck specimens from human fetuses (F) ranging from the 12th to 41st week (W) were made into histological sections. The F12W sections showed evidence that the dura mater dominated by fibroblasts, attached to the posterior atlanto-axial membrane (PAAM) which completely sealed the atlanto-axial space. In the F13W stage, myofibrils of the suboccipital muscle fibers increased significantly in number. At the F14W stage, a gap was observed at the caudal end of the PAAM. Numerous myodural bridge-like structures were observed blending into the dura mater through the gap. At the F19W stage, muscle cells mature. Starting at the F21W stage, the MDB were observed as fibroblasts that cross the atlanto-axial interspace and attach to the dura mater. Therefore, the traction generated by the suboccipital muscles seems to promote the maturity of MDB. This study will provide new morphological knowledge to support future research on the function of the human MDB and regulating the development mechanism of MDB.

Anulamycins A-F, Cinnamoyl-Containing Peptides from a Lake Sediment Derived Streptomyces.

Bioinformatics analysis of a whole genome sequence coupled with HPLC-DAD analysis revealed that Streptomyces sp. Hu103 has the capacity to produce skyllamycin analogues. A subsequent chemical investigation of this strain yielded four new cinnamoyl-containing cyclopeptides, anulamycins A-D (1-4), two new cinnamoyl-containing linear peptides, anulamycins E and F (5 and 6), and two known cyclopeptides, skyllamycins A (7) and B (8). Their structures including absolute configurations were elucidated by detailed analysis of NMR and HRESIMS/MS spectroscopic data and the advanced Marfey's method. Compounds 1-4 exhibited antibacterial activity comparable to those of skyllamycins A and B.

A new ß-class milbemycin derivative from a mutant of genetically engineered strain Streptomyces avermitilis AVE-H39.

A new ß-class milbemycin, 13α-hydroxy milbemycin ß6 (1), was isolated from the fermentation broth of a mutant of genetically engineered strain Streptomyces avermitilis AVE-H39. Its structure and absolute configuration were elucidated by extensive spectroscopic methods and confirmed by single crystal X-ray diffraction.

Two new 22-membered macrolides from Streptomyces sp. HU210.

Two new 22-membered macrolide metabolites, phthoramycins B (1) and C (2), were isolated from the fermentation broth of Streptomyces sp. HU210. Their structures were elucidated based on extensive spectroscopic techniques including 1D, 2D NMR and HRESIMS data. Compounds 1 and 2 showed moderate cytotoxic activity against human leukemia cell line K562 and lung carcinoma cell line A549.

Two new cyclopentenone metabolites from Streptomyces sp. HU119.

Two previously undescribed cyclopentenone metabolites, (S)-2-(3-acetylamino-2-methyl)propyl-3-butyl-2-cyclopenten-1-one (1) and (S)-2-(3-acetylamino-2-ethyl)propyl-3-butyl-2-cyclopenten-1-one (2), were isolated from the fermentation broth of the strain Streptomyces sp. HU119. The structures of 1 and 2 were determined by the comprehensive spectroscopic analysis, including 1 D, 2 D NMR, MS spectral analysis and the comparison with data from the literature. The absolute configurations were elucidated by experimental and calculated optical rotations (OR). Compounds 1 and 2 displayed weak cytotoxic activity.

Up-Regulation Thioredoxin Inhibits Advanced Glycation End Products-Induced Neurodegeneration.

BACKGROUND/AIMS: Diabetic retinopathy (DR) is one of the most serious complications of diabetes and is the leading cause of adult blindness in developed countries. Advanced glycation end products (AGEs) accumulation in diabetes is associated with its complications. Thioredoxin (Trx) is a small molecule (12kDa) antioxidant protein widely distributed in mammalian tissues, which has important biological functions including anti-apoptosis and transcriptional regulation. In a previous study, we found that Trx plays a key role in retinal neurodegeneration prior to the occurrence of endothelial damage in diabetic mice. In this study, our aim is to determine the effect of Trx on neurodegeneration induced by AGEs in order to identify new therapeutic targets for the clinical treatment and prevention of DR. METHODS: In vivo, a high-fat diet and Streptozotocin (STZ) injection were used to generate a mouse model of diabetes. Histology was utilized to examine tissue morphology and measure the outer nuclear layer (ONL) thickness. Electroretinography (ERG) was used to assess retinal function and Western blot was used to examine protein expression. In vitro, three methods of Trx up-regulation were used, including a stable cell line that overexpresses Trx, treatment with Sulforaphane, and shRNA down-regulation Txnip. Cells were treated with AGEs, and level of apoptosis was performed to quantify this by flow cytometry and TUNEL. Quantitative Reverse Transcription PCR (qRT-PCR), Western blotting and immunofluorescence were used to measure gene and protein expression. Transmission electron microscopy (TEM) was used to observe autophagosomes. RESULTS: We found that diabetic mice display decreased retinal function and reduced ONL thickness with AGEs accumulation and a reduction of Trx expression. Up-regulation Trx can prevent the ONL thickness decrease in diabetic mice, as observed by H&E staining. In vitro, up-regulation Trx resulted in decreased intracellular ROS generation, reduced apoptosis by inhibited autophagy. CONCLUSION: Up-regulating Trx inhibited neurodegeneration induced by AGEs. The underlying mechanism may be related to inhibit Txnip/mTOR pathway-mediated autophagy.

Neural stem cells over-expressing brain-derived neurotrophic factor promote neuronal survival and cytoskeletal protein expression in traumatic brain injury sites.

Cytoskeletal proteins are involved in neuronal survival. Brain-derived neurotrophic factor can increase expression of cytoskeletal proteins during regeneration after axonal injury. However, the effect of neural stem cells genetically modified by brain-derived neurotrophic factor transplantation on neuronal survival in the injury site still remains unclear. To examine this, we established a rat model of traumatic brain injury by controlled cortical impact. At 72 hours after injury, 2 × 107 cells/mL neural stem cells overexpressing brain-derived neurotrophic factor or naive neural stem cells (3 mL) were injected into the injured cortex. At 1-3 weeks after transplantation, expression of neurofilament 200, microtubule-associated protein 2, actin, calmodulin, and beta-catenin were remarkably increased in the injury sites. These findings confirm that brain-derived neurotrophic factor-transfected neural stem cells contribute to neuronal survival, growth, and differentiation in the injury sites. The underlying mechanisms may be associated with increased expression of cytoskeletal proteins and the Wnt/ß-catenin signaling pathway.

A novel oleanolic acid-loaded PLGA-TPGS nanoparticle for liver cancer treatment.

OBJECTIVES: Hepatocellular carcinoma is the third most common cause of cancer death. Oleanolic acid (OA) is a natural triterpenoid, has many important biological actions, including antitumor effect, but its poor solubility often leads to poor pharmacodynamics. The aim of our work is to make OA-loaded poly (lactide-co-glycolide)-d-α-tocopheryl polyethylene glycol 1000 succinate (PLGA-TPGS) nanoparticles (OPTN) to improve its efficacy to liver cancer and characterize it. METHODS: OPTN were prepared by ultrasonic emulsification-solvent evaporation technique using PLGA with or without the addition of TPGS (OPN). The coumarin-6-loaded nanoparticles were used as a fluorescence marker. The nanoparticles were characterized for surface morphology, surface charge, particle size, drug loading, encapsulation efficiency, in vitro drug-release, cellular uptake, cytotoxicity by human liver cancer cell line HepG2 cells, and therapeutic effect in vivo. KEY FINDINGS: The prepared nanoparticles were found to be spherical in shape. The in vitro drug-release profile of both nanoparticle formulations showed a biphasic release pattern. There was an increased level of uptake and cytotoxicity of OPTN in the HepG2 cells compared with that of OPN. The treatment of OPTN group was better than OPN and FS groups in vivo. CONCLUSION: The results showed advantages of OPTN in terms of sustainable release and efficacy in liver cancer chemotherapy compared with OPN. OPTN could be acted as a novel and new dosage form to be used in cancer treatment study.

Reconfirmation of the right medial division of the portal venous system of liver.

With the development of hepatic surgery and radiology, an increasing amount of researchers have reported discrepancies between the real distribution of the hepatic portal vein branches and Couinaud's segmentation, especially for further division of the right medial division. The present study investigated 25 cadaveric liver dissections and 30 three-dimensional reconstruction images of intrahepatic vessels. The ramifications, course, distribution and quantity of the portal branches were analyzed. An oblique fissure that had few vessels was found among third-order branches of the hepatic portal vein of the right medial division. The right medial division could be redivided into the ventral subsegment and dorsal subsegment by this oblique fissure. A hepatic vein coursed in the oblique fissure between the ventral subsegment and dorsal subsegment. The hepatic vein could serve as an anatomical landmark of the inter-subsegmental plane. This new method of identifying further division of the right medial division is a novel concept providing further information on conventional segmental anatomy.

A combination method for preparing casting and transparent liver specimen.

With the development of hepatic surgery and radiology, a more accurate understanding of intrahepatic vessels and hepatic segments is necessary. Previously, research in these fields was primarily by means of dissecting livers, preparing corrosion cast specimens, reconstructing three-dimensional MSCT images of intrahepatic vessels, and so on. The aim of this study was to search for a new specimen preparing method, which could demonstrate intrahepatic vessels and the relationships between internal vessels and external structures of liver simultaneously. Rabbit livers were prepared with three different techniques in this study: (a) corrosion-cast technique; (b) transparency technique; and (c) combination technique of cast and transparency. The results showed that the combination of casting and transparent liver specimens in group C could demonstrate both the intrahepatic vessels and the external structures clearly. The relationships between the internal vessels and external structures could also be observed clearly. In conclusion, the combination method for preparing casting and transparent liver specimen created a new approach for the research of intrahepatic vessels, especially for applied basic research of hepatic segments.