Six Spain Thymus essential oils composition analysis and their in vitro and in silico study against Streptococcus mutans.

BACKGROUND: Streptococcus mutans is a well-known oral pathogen that plays a critical role in the development of dental caries. Many studies have been directed to discover the chemical compounds present in natural products to inhibit the growth and biofilm formation activity of S. mutans. Thymus essential oils exhibit good inhibition on the growth and pathogenesis of S. mutans. However, details about the active compounds in Thymus essential oil and the inhibition mechanism still remain unclear. The aim of this study was to investigate the antimicrobial activity of 6 Thymus species (Three samples of Thymus vulgaris, two samples of Thymus zygis, and one sample of Thymus satureioides essential oils) on S. mutans, to identify the potential active components, and to reveal the underlying mechanism. METHODS: The composition of Thymus essential oils was analyzed by gas chromatography-mass spectrometry. And its antibacterial effect was evaluated based on the bacterial growth, acid production, biofilm formation and genetic expression of virulence factors by S. mutans. Potential active components of the Thymus essential oil were identified using molecular docking and correlation analysis. RESULTS: GC-MS analysis showed that the major components in the 6 Spain Thymus essential oils were linalool, α-terpineol, p-cymene, thymol and carvacrol. MIC and MBC analysis showed that 3 Thymus essential oils showed very sensitive antimicrobial activity, and were chosen for further analysis. The 3 Thymus essential oil exhibited a significant inhibitory effect on acid production, adherence and biofilm formation of S. mutans and the expression of virulence genes, such as brpA, gbpB, gtfB, gtfC, gtfD, vicR, spaP and relA. Correlation analysis showed that phenolic components, such as carvacrol and thymol, were positively related to DIZ value, which suggests that they are the potential antimicrobial components. Molecular docking between the Thymus essential oil components and virulence proteins also found that carvacrol and thymol exhibited strong binding affinity with functional domains of virulence genes. CONCLUSIONS: Thymus essential oil showed significant inhibition against the growth and pathogenesis of S. mutans depending on their composition and concentration. And phenolic compounds, such as carvacrol and thymol, are the major active components. Thymus essential oil could be used in oral healthcare products as a potential anti-caries ingredient.

Medial Epicanthoplasty With the Classic and Modified Skin Redraping Method: A Retrospective Case Control Study.

ABSTRACT: The skin redraping method for medial epicanthoplasty is characterized by some shortcomings which warrants modification. In this study, clinical data of 193 patients who underwent medial epichanthoplasty by the modified skin redraping technique or the classic skin redraping technique were reviewed retrospectively. The patients underwent operation between May 2018 and June 2020 and were followed up for not less than 6 months. Interepicanthal distance, interpupillary distance, patient satisfaction, and postoperative complications were evaluated. In terms of interepicanthal distance/inter-pupillary distance ratio (P > 0.05) and satisfaction score (P = 0.759), the modified skin redraping technique and the classic skin redraping technique were similar. In the classic skin redraping group, there were 3 cases of visible scarring in the lower eyelid, corresponding to significantly more cases than in the modified skin redraping group (n = 0, P < 0.001). There were more out-fold cases in the modified skin redraping group (76/90) than in the classic skin redraping group (17/88) (P < 0.001). Utilizing the modified skin redraping medial epicanthoplasty can prevent medial hooding of the upper eyelid, reduce the probability of visible scarring, and produce more out-fold with concurrent double eyelidplasty compared with classic skin redraping epicanthoplasty. Level of evidence: IV.

Antibacterial Peptide HHC-36 Sustained-Release Coating Promotes Antibacterial Property of Percutaneous Implant.

Percutaneous implants are widely used in clinical practice. However, infection is the main clinical problem of percutaneous implants. Titanium dioxide nanotubes are suitable for forming coatings on complex surfaces such as implants. HHC-36, a cationic antimicrobial peptide, has been identified to have a strong broad-spectrum antibacterial effect. In the present study, we use poly D,L-lactic acid (PDLLA) and poly lactic-co-glycolic acid (PLGA) coating to build HHC-36 sustained-release system on the surface of titanium dioxide nanotubes. The titanium specimens were anodized coated with HHC-36-PDLLA/PLGA. The morphology and surface elemental distribution of the specimens were evaluated. Besides, results in the present study demonstrated that with antibacterial peptide HHC-36 sustained-release coating, titanium dioxide nanotubes maintain effective drug release for 15 days in vitro, and show significant antibacterial activity. The proliferation of Staphylococcus aureus can be effectively inhibited by PDLLA/PLGA-HHC-36 coated titanium dioxide nanotube. In addition, PDLLA-HHC-36 and PLGA-HHC-36 coating was demonstrated to be biocompatible and antibacterial in vivo. These findings demonstrated that HHC-36 coated titanium nanotube could improve antibacterial potential of percutaneous implants, and indicated a novel and efficient strategy in preventing bacterial infection of percutaneous implants.

Conditional deletion of Adrb2 in mesenchymal stem cells attenuates osteoarthritis-like defects in temporomandibular joint.

ß2-adrenergic signal transduction in mesenchymal stem cells (MSCs) induces subchondral bone loss in osteoarthritis (OA) of temporomandibular joints (TMJs). However, whether conditional deletion of ß2-adrenergic receptor (Adrb2) in nestin+ MSCs can alleviate TMJ-OA development remains unknown. In this study, nestin-Cre mice were crossed with Adrb2 flox mice to generate mice lacking Adrb2 expression specifically in the nestin+ MSCs (Adrb2-/-), and TMJ-OA development in such mice was investigated. Adrb2 flox mice (Adrb2+/+) and Adrb2-/- mice were subjected to unilateral anterior crossbite (UAC), while mice in the control group were subjected to sham operation. Adrb2+/+ and Adrb2-/- mice in the control group showed no distinguishable phenotypic changes in body weight and length, mandibular condylar size, and other histomorphological parameters of the condylar subchondral bone. A significant increase in subchondral bone loss and cartilage degradation was observed in Adrb2+/+ UAC mice; the former was characterized by decreased bone mineral density, bone volume fraction, and trabecular plate thickness, and increased trabecular separation, osteoclast number and osteoclast surface, and pro-osteoclastic factor expression; the latter was characterized by decreased cartilage thickness, chondrocyte density, proteoglycan area, and collagen II and aggrecan expression, but increased matrix metalloproteinase and alkaline phosphatase expression and percentage area of calcified cartilage. Adrb2 deletion in nestin+ MSCs largely attenuated UAC-induced increase in condylar subchondral bone loss, cartilage degradation, and aberrant calcification at the osteochondral interface. Thus, Adrb2-expressing MSCs in the condylar subchondral bone play an important role in TMJ-OA progression and may serve as novel therapeutic targets for TMJ-OA.

Contribution of Mitophagy to Cell-Mediated Mineralization: Revisiting a 50-Year-Old Conundrum.

Biomineralization in vertebrates is initiated via amorphous calcium phosphate (ACP) precursors. These precursors infiltrate the extracellular collagen matrix where they undergo phase transformation into intrafibrillar carbonated apatite. Although it is well established that ACP precursors are released from intracellular vesicles through exocytosis, an unsolved enigma in this cell-mediated mineralization process is how ACP precursors, initially produced in the mitochondria, are translocated to the intracellular vesicles. The present study proposes that mitophagy provides the mechanism for transfer of ACP precursors from the dysfunctioned mitochondria to autophagosomes, which, upon fusion with lysosomes, become autolysosomes where the mitochondrial ACP precursors coalesce to form larger intravesicular granules, prior to their release into the extracellular matrix. Apart from endowing the mitochondria with the function of ACP delivery through mitophagy, the present results indicate that mitophagy, triggered upon intramitochondrial ACP accumulation in osteogenic lineage-committed mesenchymal stem cells, participates in the biomineralization process through the BMP/Smad signaling pathway.

Intrafibrillar silicified collagen scaffold promotes in-situ bone regeneration by activating the monocyte p38 signaling pathway.

Intrafibrillar silicified collagen scaffold (SCS) is a promising biomaterial for bone regeneration because it promotes cell homing and angiogenesis in bone defects via monocyte modulation. In the present study, a rat femoral defect model was used to examine the contribution of monocyte signaling pathways to SCS modulation. Activation of the monocyte p38 signaling pathway by SCS resulted in monocyte differentiation into TRAP-positive mononuclear cells. These cells demonstrated increased secretion of SDF-1α, VEGFa and PDGF-BB, which, in turn, promoted homing of bone marrow stromal cells (BMSCs) and endothelial progenitor cells (EPCs), as well as local vascularization. Monocyte differentiation and secretion were blocked after inhibition of the p38 pathway, which resulted in reduction in cell homing and angiogenesis. Taken together, these novel findings indicate that the p38 signaling pathway is crucial in SCS-modulated monocyte differentiation and secretion, which has a direct impact on SCS-induced bone regeneration. STATEMENT OF SIGNIFICANCE: Intrafibrillar silicified collagen scaffold (SCS) is a promising biomaterial for bone regeneration. The present work demonstrates that SCS possesses favorable bone regeneration potential in a rat femoral defect model. The degrading scaffold modulates monocyte differentiation and release of certain cytokines to recruit MSCs and EPCs, as well as enhances local vascularization by activating the p38 MAPK signaling pathway. These findings indicate that SCS contributes to bone defect regeneration by stimulating host cell homing and promoting local angiogenesis and osteogenesis without the need for loading cytokines or xenogenous stem cells.

Biodegradable mesoporous delivery system for biomineralization precursors.

Scaffold supplements such as nanoparticles, components of the extracellular matrix, or growth factors have been incorporated in conventional scaffold materials to produce smart scaffolds for tissue engineering of damaged hard tissues. Due to increasing concerns on the clinical side effects of using large doses of recombinant bone-morphogenetic protein-2 in bone surgery, it is desirable to develop an alternative nanoscale scaffold supplement that is not only osteoinductive, but is also multifunctional in that it can perform other significant bone regenerative roles apart from stimulation of osteogenic differentiation. Because both amorphous calcium phosphate (ACP) and silica are osteoinductive, a biodegradable, nonfunctionalized, expanded-pore mesoporous silica nanoparticle carrier was developed for loading, storage, and sustained release of a novel, biosilicification-inspired, polyamine-stabilized liquid precursor phase of ACP for collagen biomineralization and for release of orthosilicic acid, both of which are conducive to bone growth. Positively charged poly(allylamine)-stabilized ACP (PAH-ACP) could be effectively loaded and released from nonfunctionalized expanded-pore mesoporous silica nanoparticles (pMSN). The PAH-ACP released from loaded pMSN still retained its ability to infiltrate and mineralize collagen fibrils. Complete degradation of pMSN occurred following unloading of their PAH-ACP cargo. Because PAH-ACP loaded pMSN possesses relatively low cytotoxicity to human bone marrow-derived mesenchymal stem cells, these nanoparticles may be blended with any osteoconductive scaffold with macro- and microporosities as a versatile scaffold supplement to enhance bone regeneration.

Intrafibrillar silicified collagen scaffold modulates monocyte to promote cell homing, angiogenesis and bone regeneration.

The immunomodulatory functions of monocytes are increasingly being recognized. Silicified collagen scaffolds (SCSs), produced by infiltrating collagen matrices with intrafibrillar amorphous silica, exhibit osteogenic and angiogenic potential and are promising candidates in tissue engineering. Here, we demonstrate that SCS promotes in situ bone regeneration and angiogenesis via monocyte immunomodulation. Increased numbers of TRAP-positive monocytes, nestin-positive bone marrow stromal cells (BMSCs) and CD31-positive and endomucin-positive new vessels can be identified from new bone formation regions in a murine calvarial defect model. In addition, sustained release of silicic acid by SCS stimulates differentiation of blood-derived monocytes into TRAP-positive cells, with increased expressions of SDF-1α, TGF-ß1, VEGFa and PDGF-BB. These cytokines further promote homing of BMSCs and endothelial progenitor cells as well as neovascularization. Taken together, these novel findings indicate that SCSs possess the ability to enhance recruitment of progenitor cells and promote osteogenesis and angiogenesis by immunomodulation of monocytes.

Multiple Evolutionary Events Involved in Maintaining Homologs of Resistance to Powdery Mildew 8 in Brassica napus.

The Resistance to Powdery Mildew 8 (RPW8) locus confers broad-spectrum resistance to powdery mildew in Arabidopsis thaliana. There are four Homologous to RPW8s (BrHRs) in Brassica rapa and three in Brassica oleracea (BoHRs). Brassica napus (Bn) is derived from diploidization of a hybrid between B. rapa and B. oleracea, thus should have seven homologs of RPW8 (BnHRs). It is unclear whether these genes are still maintained or lost in B. napus after diploidization and how they might have been evolved. Here, we reported the identification and sequence polymorphisms of BnHRs from a set of B. napus accessions. Our data indicated that while the BoHR copy from B. oleracea is highly conserved, the BrHR copy from B. rapa is relatively variable in the B. napus genome owing to multiple evolutionary events, such as gene loss, point mutation, insertion, deletion, and intragenic recombination. Given the overall high sequence homology of BnHR genes, it is not surprising that both intragenic recombination between two orthologs and two paralogs were detected in B. napus, which may explain the loss of BoHR genes in some B. napus accessions. When ectopically expressed in Arabidopsis, a C-terminally truncated version of BnHRa and BnHRb, as well as the full length BnHRd fused with YFP at their C-termini could trigger cell death in the absence of pathogens and enhanced resistance to powdery mildew disease. Moreover, subcellular localization analysis showed that both BnHRa-YFP and BnHRb-YFP were mainly localized to the extra-haustorial membrane encasing the haustorium of powdery mildew. Taken together, our data suggest that the duplicated BnHR genes might have been subjected to differential selection and at least some may play a role in defense and could serve as resistance resource in engineering disease-resistant plants.

Ectopic expression of RESISTANCE TO POWDERY MILDEW8.1 confers resistance to fungal and oomycete pathogens in Arabidopsis.

Broad-spectrum disease resistance is a highly valuable trait in plant breeding and attracts special attention in research. The Arabidopsis gene locus RESISTANCE TO POWDERY MILDEW 8 (RPW8) contains two adjacent homologous genes, RPW8.1 and RPW8.2, and confers broad-spectrum resistance to powdery mildew. Remarkably, the RPW8.2 protein is specifically localized to the extrahaustorial membrane (EHM) encasing the feeding structure of powdery mildew whereby RPW8.2 activates haustorium-targeted defenses. Here, we show that ectopic expression of the yellow fluorescent protein (YFP)-tagged RPW8.1 from the native promoter leads to unique cell death lesions and enhances resistance to virulent fungal and oomycete pathogens that cause powdery mildew and downy mildew diseases, respectively. In powdery mildew-infected plants, RPW8.1-YFP accumulates at higher levels in the mesophyll cells underneath the infected epidermal cells where RPW8.2-YFP is mainly expressed. This cell type-preferential protein accumulation pattern largely correlates with that of H(2)O(2) accumulation, suggesting that RPW8.1 may spatially collaborate with RPW8.2 in activation of resistance to powdery mildew. Interestingly, when ectopically expressed from the RPW8.2 promoter, RPW8.1-YFP is also targeted to the EHM of powdery mildew and the transgenic plants display resistance to both powdery mildew and downy mildew. Using YFP as a reporter, we further reveal that the RPW8.1 promoter is constitutively active but induced to higher levels in cells at the infection site, whereas the RPW8.2 promoter is activated specifically in cells at the infection site. Taken together, our results suggest that RPW8.1 (and its promoter) is functionally distinct from RPW8.2 and may have a higher potential in engineering broad-spectrum resistance in plants.

[Effects of endothelial progenitor cell-conditioned medium on the proliferation, adhesion and migration of vascular smooth muscle cells].

OBJECTIVE: To investigate the effects of endothelia progenitor cells conditioned medium (EPC-CM) on the migration, adhesion and proliferation of vascular smooth muscle cells (VSMCs). METHODS: Mononuclear cells were isolated from rat bone marrow by density gradient centrifugation,plated on dishes precoated with 5% fibronectin, and then cultured with complete M199 medium (including 15% fetal calf serum, 10 microg/L VEGF and 5 microg/L bFGF). EPC-CM was collected and used to incubate VSMCs isolated from rat arteriae aorta. After 24 h, VSMCs proliferation, adhesion and migration were assayed with CCK-8, adhesion test and modified Boyden chamber assay, respectively. RESULTS: The proliferation, adhesion and migration of VSMCs were obviously decreased when the cells were cultured with EPC-CM. CONCLUSION: EPC-CM could inhibit VSMC functions, which would be one of the mechanisms against atherosclerosis by EPCs.

[Effects of extracellular matrix on biological characteristics of late endothelial progenitor cells].

The present study was designed to investigate the effects of various extracellular matrix (ECM) proteins on the biological characteristics of late endothelial progenitor cells (EPCs). Density gradient centrifugation-isolated rat bone marrow mononuclear cells were cultured in complete M199 medium, which contained 15% fetal calf serum, 10 µg/L vascular endothelial growth factor (VEGF) and 5 µg/L basic fibroblast growth factor (bFGF). EPCs were plated on substrates containing fibronectin (Fn), laminin (Ln) or rat tail tendon collagen (Col), and the corresponding cells were defined as Fn, Ln and Col groups. The 3rd generation EPCs, namely late EPCs, were harvested. The proliferation, adhesion, migration and the ability of forming tubes were assayed using CCK-8, adhesion test, wound healing assay and Matrigel, respectively. The mRNA expressions of endothelial cell differentiation markers, vWF and CD31, were analyzed by real time RT-PCR. The apoptosis was assayed by flow cytometry (FCM). The results showed that cell proliferation ability of Fn and Col groups were higher than that of Ln group; Fn group showed increased adhesion compared to Col and Ln groups (P < 0.01); The migration ability of Fn and Col groups were higher than that of Ln group. Moreover, Fn group showed increased tube formation abilities compared to Col and Ln groups (P < 0.05). Although 24-hour free-serum-induced apoptosis in Ln group was the highest, there was no difference of auto-apoptosis among the three groups. Furthermore, the mRNA expressions of vWF and CD31 exhibited no difference among the three groups. These results suggest the ECM affects the biological functions of late EPCs, which would have a high probability of providing new directions that lead to the development of artificial heart and blood vessels.

Effects of Er'zhi Tiangui Granule () on sequential expressions of integrin ß 3 and its ligand osteopontin in mouse endometrium during controlled ovarian hyperstimulation.

OBJECTIVE: To investigate the effects of Er'zhi Tiangui Granule (, ETG) on sequential expressions of integrinß3 and its ligand osteopontin in the mouse endometrium during controlled ovarian hyperstimulation (COH) and implantation period. METHODS: Seventy-five Mature female Kunming mice were randomly divided into 3 groups, a normal control group, a model group, and a treatment group administrated with ETG for 10 days, 25 in each group. After mated with male mice, every 5 mice were sacrified in each group at the 0, 2nd, 4th, 6th, and 8th days to take their endometrium. In-situ hybridization was used to detect the expressions of integrinß3 and osteopontin in the endometrium. RESULTS: mRNA expressions of integrinß3 and osteopontin in the endometrium during implantation period showed similar time sequence rules in the treatment group to those in the normal control group; the peak values of them were a little lower in the treatment group than the normal control without significant differences. In the model group, integrinß3 mRNA expression was higher at the 2nd day, obviously lower at the 4th and 6th days, and insignificantly lower at the 8th day; and osteopontin expression was remarkably lower at the 4th, 6th, and 8th days, compared with the normal control and the treatment groups (P<0.05, P<0.01). CONCLUSIONS: COH might influence the sequential expressions of integrinß3 and its ligand osteopontin, bring forward the integrinß3 expression peak, impact on the cooperation of integrinß3 and osteopontin, so as to damage the endometrial receptivity. ETG could regulate the sequential expressions of integrinß3 and its ligand osteopontin to improve the mouse endometrial receptivity during COH.

[Shengjing prescription improves semen parameters of oligoasthenozoospermia patients: efficacy and mechanism].

OBJECTIVE: To investigate the clinical efficacy of Shengjing prescription for oligoasthenozoospermia and its action mechanism. METHODS: We equally assigned 120 patients with oligoasthenozoospermia to receive Shengjing prescription (treatment group) and vitamin E (control group), respectively, for 12 weeks. Before and after the treatment, were obtained sperm concentration, sperm motility, the percentage of morphologically normal sperm, the levels of serum follicle-stimulating hormone (FSH), testosterone (T) and luteinizing hormone (LH), sperm DNA fragmentation index (DFI), the percentage of hypotonic swelling sperm, and the levels of seminal plasma elastase, x-glucosidase, fructose, zinc and acrosin. RESULTS: Compared with vitamin E, Shengling prescription significantly improved sperm concentration, motility and morphology (P < 0.01), decreased the serum FSH level, elevated the serum T level (P <0. 01) , reduced DFI and seminal plasma elastase, and increased the percentage of hypotonic swelling sperm as well as the levels of seminal plasma cx-glucosidase, fructose, zinc and acrosin. CONCLUSION: Shengjing prescription improves semen parameters of patients with oligoasthenozoospermia at multiple levels and through multiple channels.

[Clinical experiences of normal saline pressed injection via lumbar puncture in the treatment of apnea due to acute tonsillar hernia].

OBJECTIVE: To summarize the clinical experiences of normal saline pressed injection via lumbar puncture in the treatment of acute tonsillar hernia induced apnea. This procedure was routinely carried out after external ventricular drainage and/or lesion removal via open craniotomy. METHODS: During the period of 1969 to 2005, a total of 43 patients failed to regain respiratory after external ventricular drainage using rapid small hole cranio-puncture apparatus or lesion removal via open craniotomy. They underwent lumbar puncture and normal saline was pressed injected via a lumbar puncture needle. The patient data were retrospectively analyzed. RESULTS: Eleven of 43 patients had spontaneous respiration and fully recovered (25.6%), 16 patients regained respiration but died eventually (37.2%) and 16 patients failed to regain respiration (37.2%). The effective rate was 62.8%. CONCLUSION: For the patients failing to regain respiration after external ventricular drainage or supratentorial lesion removal via open craniotomy, the conservative treatment should not be the first choice. The pressed injection of normal saline via lumbar puncture may rescue some patients.

Survival and differentiation of neuroepithelial stem cells on chitosan bicomponent fibers.

Chitosan is a popular biomaterial used in tissue engineering. Fibers of chitosan could provide a favorable anatomical substrate for cell growth which provides a promising application for axonal regeneration during peripheral injury. Neuroepithelial stem cells (NEPs) are the most primitive neural stem cells with multipotential for neuronal and glia differentiation. To assess the biocompatibility between NEPs and chitosan fibers, and to explore whether the NEPs have the ability to differentiation on chitosan fibers, NEPs were harvested from the neural tube and seeded on chitosan fibers in in vitro culture. The biocompatibility of chitosan fibers was tested by MTT assays. The growth and survival were observed by light and scanning electronic microscope at different times in culture. And, the differentiation of NEPs was examined by immunocytochemical staining. The results indicated that NEPs could grow on the chitosan fibers and attach firmly to the surface of fibers. On chitosan fibers, NEPs could differentiate into neurons and glia. Our study demonstrated that chitasan fibers had a good biocompatibility with NEPs which affords a potential alternative for the repair of peripheral nerve injury.

Endoscopic and microscopic anatomy of the superior sagittal sinus and torcular herophili.

Surgery of the superior sagittal sinus (SSS) is a challenging areas for neurosurgeons. To better understand the anatomy of the SSS, we examined the chordae and arachnoid granulations in the lumen of the SSS and torcular herophili with the aid of an endoscope and a microscope, and re-evaluated the role of the chordae Willisii in preventing blood backflow. We prepared 10 SSS from fresh human cadavers during autopsies. After the cranial vaults were removed, an endoscope was inserted into the lumen of the sinus to examine the structures and morphological features of the chordae Willisii, and the topographic distribution of the arachnoid granulations. The sinuses were subsequently opened using standard anatomical methods and the intraluminal structures of the dural sinus were subjected to microanatomic analysis. In another five formalin-embalmed cadaver heads, blue latex was injected from the posterior end of the SSSs to observe filling of the SSS tributaries. We identified three types of chordae in the lumen of the SSS: valve-like chordae (48.3% of all chordae), followed by trabecular (31.5%) and laminar (20.2%) chordae. The laminar chordae at the posterior end of the SSS divide the sinus into two separate channels of different sizes. Similar structures were also seen in the lumen of the torcular herophili. The majority of arachnoid granulations were found as digitations in the lumen at the lateral wall or lateral recess of the middle segment of the SSS. Microscopic examination of the intraluminal structures of the SSS confirmed endoscopic findings. In the injection test we found that the SSS tributaries could be filled retrogradely with artificial dye, suggesting that the function of valve-like chordae in preventing the backflow of blood is restricted only to physiological conditions. Thus, we could visualize and examine endoscopically the intact intraluminal structures of the SSS, which may have therapeutic or diagnostic significance.

Clinical analysis for an unusual large cystic meningioma: case report and review of the literature.

The authors report the case of a 17-year-old boy with an unusual large cystic meningioma (Nauta type II) in the right hemisphere. The imaging appearances of this patient were very unusual. The shape of the huge cyst was crescentic and similar to subdural hematoma. It lay between the dura and the solid tumor parts. In addition there was a small intracystic nodule attached to the cyst wall. The patient underwent a right hemisphere craniotomy. At surgery it was found that the cyst contained a large amount of xanthochromic fluid and some semitransparent serumlike sediment. The intracystic nodule was proved to be necrotic substance without tissue and cell structure. Histological examination displayed an anaplastic meningioma, of which the cyst wall also consisted of meningioma tissue. To the best of the authors' knowledge, such an unusual case of cystic meningioma has not been reported. The authors review the literature with reference to intratumoral cyst associated with meningiomas, analyze the unusual imaging appearances of this patient, and explore the mechanism of cyst formation. The mechanism of cyst formation associated with meningiomas is not perfectly understood. Intratumoral cyst formation may be attributed to microcystic degeneration, ischemic necrosis, intratumoral hemorrhage, transudation and secretory changes within the tumor.