Magnetic resonance imaging-based classification of the myodural bridge complex and its influencing factors.

Cerebrospinal fluid (CSF) circulation is considered the third circulation of the human body. Recently, some scholars have proposed the myodural bridge (MDB) as a novel power source for CSF flow. Moreover, the suboccipital muscles can exert a driving force on the CSF via the MDB. This hypothesis is directly supported by head rotation and nodding movements, which can affect CSF circulation. The MDB has been validated as a normal structure in humans and mammals. In addition, the fusion of MDB fibers of different origins that act in concert with each other forms the MDB complex (MDBC). The MDBC may be associated with several CSF disorder-related neurological disorders in clinical practice. Therefore, the morphology of the MDBC and its influencing factors must be determined. In this study, T2-weighted imaging sagittal images of the cervical region were analyzed retrospectively in 1085 patients, and magnetic resonance imaging (MRI) typing of the MDBC was performed according to the imaging features of the MDBC in the posterior atlanto-occipital interspace (PAOiS) and posterior atlanto-axial interspace (PAAiS). The effects of age and age-related degenerative changes in the cervical spine on MRI staging of the MDBC were also determined. The results revealed four MRI types of the MDBC: type A (no MDBC hyposignal shadow connected to the dura mater in either the PAOiS or PAAiS), type B (MDBC hyposignal shadow connected to the dura mater in the PAOiS only), type C (MDBC hyposignal shadow connected to the dura mater in the PAAiS only), and type D (MDBC hyposignal shadow connected to the dura mater in both the PAOiS and PAAiS). The influencing factors for the MDBC typing were age (group), degree of intervertebral space stenosis, dorsal osteophytosis, and degenerative changes in the cervical spine (P < 0.05). With increasing age (10-year interval), the incidence of type B MDBC markedly decreased, whereas that of type A MDBC increased considerably. With the deepening of the degree of intervertebral space stenosis, the incidence of type C MDBC increased significantly, whereas that of type A MDBC decreased. In the presence of dorsal osteophytosis, the incidence of type C and D MDBCs significantly decreased, whereas that of type A increased. In the presence of protrusion of the intervertebral disc, the incidence of type B, C, and D MDBCs increased markedly, whereas that of type A MDBC decreased considerably, with cervical degenerative changes combined with spinal canal stenosis. Moreover, the incidence of both type C and D MDBCs increased, whereas that of type A MDBC decreased. Based on the MRI signal characteristics of the dural side of the MDBC, four types of the MDBC were identified. MDBC typing varies dynamically according to population distribution, depending on age and cervical degeneration (degree of intervertebral space stenosis, vertebral dorsal osteophytosis formation, simple protrusion of intervertebral disc, and cervical degeneration changes combined with spinal canal stenosis, except for the degree of protrusion of the intervertebral disc and the degree of spinal canal stenosis); however, it is not influenced by sex.

Decreased cuticular penetration minimizes the impact of the pyrethroid insecticide λ-cyhalothrin on the insect predator Eocanthecona furcellata.

The use of broad-spectrum pesticides may reduce the biological control efficacy of predatory arthropods. Hence, the risks of pesticides to predators need to be evaluated. Here, we assessed the effects of a broad spectrum pyrethroid λ-cyhalothrin on a polyphagous predatory insect Eocanthecona furcellata via contact exposure route. The recommended application rate of λ-cyhalothrin was lower than the LR50 and HQ (in-field) was equal to 0.57, indicating the risk of λ-cyhalothrin to E. furcellata was low. Dried λ-cyhalothrin residue had no effect on the mortality, body weight, protein content of cuticle, or activities of major detoxification enzymes in E. furcellata. Residual of λ-cyhalothrin was only detected in the cuticle and legs of E. furcellata with a decreasing trend as time went by and no λ-cyhalothrin was detected inside the body. Additionally, a comparative transcriptome analysis was conducted to study global changes in gene expression in E. furcellata at different time points following exposure to λ-cyhalothrin-contaminated environment. A total of 57,839 unigenes with an average length of 1044 bp and an N50 of 1820 bp were obtained. In total, 118 and 109 differentially expressed genes (DEGs) at 12 h, and 60 h were identified between two groups. The DEGs were largely enriched in functional categories related to the structural constituent of cuticle. Accordingly, multiple cuticle protein-coding genes were up-regulated at 12 h after pesticide exposure. The present study stressed the importance of evaluating the compatibility between a specific pesticide (λ-cyhalothrin) and E. furcellata via simulating the releasing predators after insecticide application. The data could help optimize the pesticide use, optimizing the ecological services of E. furcellata as a BCA, and expanding its use into more areas of agriculture.

Apatinib inhibits tumour progression and promotes antitumour efficacy of cytotoxic drugs in oesophageal squamous cell carcinoma.

Apatinib, a highly selective inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2), inhibits the angiogenesis of tumours. The function and mechanism of apatinib in oesophageal squamous cell carcinoma (ESCC) remain unknown. In present study, we found that the development of ESCC in patients was controlled by treatment of combination of apatinib and a chemotherapeutic drug. Moreover, apatinib efficiently promotes cell apoptosis, inhibits cell proliferation, invasion, epithelial-mesenchymal transition (EMT) and activity of the Akt/mTOR pathway in ESCC cells. Western blot analysis showed that apatinib significantly increased vimentin protein levels, decreased Bcl2, matrix metalloproteinase 9 (MMP9), E-cadherin, p-Akt and p-mTOR protein levels in ESCC cells. Furthermore, apatinib enhanced chemosensitivity of cytotoxic drugs paclitaxel (TAX), 5-fluorouracil (5-FU) and cisplatin (DDP) by upregulating expression of vimentin protein, and downregulating expression of Bcl2, MMP9 and E-cadherin protein in vitro. Compared with single-agent groups, the combination of apatinib with each chemotherapeutic drug significantly repressed tumour growth and angiogenesis through blocking the expression of Ki67 and VEGFR-2 in vivo. Taken together, apatinib efficiently inhibits cell growth through blocking Bcl2 and Akt/mTOR pathway, and suppresses metastasis via inhibiting MMP9 and EMT in ESCC cells. Apatinib promoted antitumour effect of chemotherapeutic agents through promoting cell apoptosis and inhibiting EMT and angiogenesis in ESCC.

A new concept of the fiber composition of cervical spinal dura mater: an investigation utilizing the P45 sheet plastination technique.

PURPOSE: Few reports have been published regarding the microanatomy of the dura mater located at the craniovertebral junction (CVJ). In clinic, the precise microanatomy of the CVJ dura mater would be taken into account, for reducing surgical complications and ineffective surgical outcomes. The main objective of the present investigation was to further elucidate the fiber composition and sources of the cervical spinal dura mater. METHODS: The formalin-fixed adult head and neck specimens (n = 21) were obtained and P45 plastinated section method was utilized for the present study. The fibers of the upper cervical spinal dura mater (SDM) were examined in the P45 sagittal sections in the CVJ area. All photographic documentation was performed via a Canon EOS 7D Mark camera. RESULTS: The posterior wall of the SDM sac at CVJ was found to be composed of stratified fibers, which are derived from three sources: the cerebral dura mater, the occipital periosteum, and the myodural bridge (MDB). The proper layer of the cerebral dura mater passes over the brim of the foramen magnum and enters the vertebral canal to form the inner layer of the SDM, and the fibers originating from the periosteum of the brim of the foramen magnum form the middle layer. The fibers of the MDB are inserted into the SDM and form its outer layer. It was found that the total number of fibers from each origin varied in humans. CONCLUSION: At the CVJ, the posterior wall of the SDM is a multi-layered structure composed of three different originated fibers. The cerebral dura mater, the periosteum located at the brim of the foramen magnum, and MDB contribute to the formation of the SDM. The present study would be beneficial to the choice of surgical approach at the CVJ and the protection of the SDB.

Architecture of the cancellous bone in human proximal tibia based on P45 sectional plastinated specimens.

PURPOSE: To reveal differences in the pattern of trabecular architecture in the epiphysis and metaphysis of the proximal tibia. METHODS: The trabecular architecture of the proximal tibia was observed in 27 P45 plastinated knee specimens. RESULTS: In the medial and lateral condyles, under the articular cartilage surrounded by the medial or lateral meniscus, the cancellous bone is formed by thick and dense trabecular bands, which run longitudinally in the epiphysis and then pass through the epiphyseal line to terminate on the slanted cortex of the metaphysis. In the intercondylar eminence, the trabeculae are arranged basically in a network. In the central portion of the tibial metaphysis, cancellous bone consists of fine arcuate trabeculae, which extend to the anterior and posterior cortices, respectively. These trabeculae are intersected sparsely and form trusses over the medullary cavity. Near the areas of attachment of the iliotibial tract, tibial collateral ligament, anterior and posterior cruciate ligaments, and patellar ligament, the cancellous bone is locally reinforced with patchy trabeculae, dense radiating trabeculae, or two orthotropic trabecular bands. CONCLUSION: This study provides further accurate anatomical information on the trabeculae of the proximal tibia. The soft structures of knee joint, including the articular cartilage, menisci, and ligaments, and the slanted cortices of the metaphysis are important landmarks for the location of different arrangements of the cancellous architecture. The present results are beneficial for clinical diagnosis and treatment of pathologies of the knee joint, or the establishment of a finite element analysis model of the knee joint.

Environmental function zoning for spatially differentiated environmental policies in China.

Different regions in China face greatly dissimilar ecological and environmental problems due to large variations in natural conditions and socioeconomic development levels. Such spatial variability calls for regionalized environmental management and protection policies. Environmental function zoning is an effective tool for the design and implementation of differentiated environmental policies. To contain the ecological degradation in different regions of China, we first created a comprehensive environmental function evaluation index system that included 25 socioeconomic and environmental indicators for the three key elements of natural ecological security protection, healthy human living environment maintenance, and regional environment carrying capacity. To clarify the division of Chinese environmental function zoning in the new period, we use GIS and remote sensing technology. We generated 1-km resolution grid data for the 25 indicators and implemented this index system to evaluate the environmental function of the 2414 counties in China. Differentiated environmental management objectives and strategies were designed and implemented for different zones to avoid the phenomenon of one size fits all. This work lays a scientific foundation and provides a quantitative tool for the design and implementation of differentiated management. By considering not only the natural system but also the social and economic systems and their interactions, this evaluation of environmental function provides a more comprehensive view and thus offers new insights on balancing environmental protection and socioeconomic development.

The myodural bridge complex defined as a new functional structure.

PURPOSE: The connective tissue between suboccipital muscles and the cervical spinal dura mater (SDM) is known as the myodural bridge (MDB). However, the adjacent relationship of the different connective tissue fibers that form the MDB remains unclear. This information will be highly useful in exploring the function of the MDB. METHODS: The adjacent relationship of different connective tissue fibers of MDB was demonstrated based upon three-dimensional visualization model, P45 plastinated slices and histological sections of human MDB. RESULTS: We found that the MDB originating from the rectus capitis posterior minor muscle (RCPmi), rectus capitis posterior major muscle (RCPma) and obliquus capitis inferior muscle (OCI) in the suboccipital region coexists. Part of the MDB fibers originate from the ventral aspect of the RCPmi and, together with that from the cranial segment of the RCPma, pass through the posterior atlanto-occipital interspace (PAOiS) and enter into the posterior aspect of the upper cervical SDM. Also, part of the MDB fibers originate from the dorsal aspect of the RCPmi, the ventral aspect of the caudal segment of the RCPma, and the ventral aspect of the medial segment of the OCI, enter the central part of the posterior atlanto-axial interspace (PAAiS) and fuse with the vertebral dura ligament (VDL), which connects with the cervical SDM. CONCLUSIONS: Our findings prove that the MDB exists as a complex structure which we termed the 'myodural bridge complex' (MDBC). In the process of head movement, tensile forces could be transferred possibly and effectively by means of the MDBC. The concept of MDBC will be beneficial in the overall exploration of the function of the MDB.

miR-516a-3p inhibits breast cancer cell growth and EMT by blocking the Pygo2/Wnt signalling pathway.

miR-516a-3p has been reported to play a suppressive role in several types of human tumours. However, the expression level, biological function and fundamental mechanisms of miR-516a-3p in breast cancer remain unclear. In the present study, we found that miR-516a-3p expression was down-regulated and Pygopus2 (Pygo2) expression was up-regulated in human breast cancer tissues and cells. Through analysing the clinicopathological characteristics, we demonstrated that low miR-516a-3p expression or positive Pygo2 expression was a predictor of poor prognosis for patients with breast cancer. The results of a dual luciferase reporter assay and Western blot analysis indicated that Pygo2 was a target gene of miR-516a-3p. Moreover, overexpression of miR-516a-3p inhibited cell growth, migration and invasion as well as epithelial-mesenchymal transition (EMT) of breast cancer cells, whereas reduced miR-516a-3p expression promoted breast cancer cell growth, migration, invasion and EMT. Furthermore, we showed that miR-516a-3p suppressed cell proliferation, metastasis and EMT of breast cancer cells by inhibiting Pygo2 expression. We confirmed that miR-516a-3p exerted an anti-tumour effect by inhibiting the activation of the Wnt/ß-catenin pathway. Finally, xenograft tumour models were used to show that miR-516a-3p inhibited breast cancer cell growth and EMT via suppressing the Pygo2/Wnt signalling pathway. Taken together, these results show that miR-516a-3p inhibits breast cancer cell growth, metastasis and EMT by blocking the Pygo2/ Wnt/ß-catenin pathway.

ZKSCAN3 promotes breast cancer cell proliferation, migration and invasion.

ZKSCAN3, a zinc-finger transcription factor, which has been shown to be upregulated in several human cancer. However, the expression level, function and mechanism of ZKSCAN3 in breast cancer remains unknown. In the current study, immunohistochemistry, western blot and quantitative real time polymerase chain reaction (qRT-PCR) results showed that ZKSCAN3 was overexpressed in breast cancer tissue compared with normal breast tissue. Through analyzing the clinicopathological characteristics, we demonstrated that positive ZKSCAN3 expression predicted poor prognosis of patients with breast cancer. The expression level of ZKSCAN3 protein/mRNA in breast cancer cells (MCF-7 and MDA-MB-231) was higher than its expression in normal breast cells (HBL-100). Knocking down ZKSCAN3 via its short hairpin RNA (shRNA) in MCF-7 and MDA-MB-231 inhibited cell viability, migration and invasion. Western blot analysis showed that ZKSCAN3 silencing lead to significant decreases in the expression of Cyclin D1, B-cell lymphoma-2 (Bcl-2), and matrix metalloproteinase (MMP)-2/MMP-9, as well as increases in the expression of Bcl2 Associated X Protein (Bax) in breast cancer cells. Additionally, ZKSCAN3-shRNA expression markedly suppressed tumor growth in breast cancer xenograft mice. Finally, we demonstrated that silencing of ZKSCAN3 was able to inhibit Akt/mTOR signaling pathway by blocking p-Akt and p-mTOR protein expression in breast cancer cells. These results demonstrate that ZKSCAN3 plays a significant role in the progression of breast cancer. Therefore, ZKSCAN3 is a potential therapeutic target for breast cancer.

Fenoxaprop-P-ethyl and mesosulfuron-methyl resistance status of shortawn foxtail (Alopecurus aequalis Sobol.) in eastern China.

Resistance to the acetyl-coenzyme A carboxylase (ACCase)- and acetolactate synthase (ALS)- inhibiting herbicides in shortawn foxtail (Alopecurus aequalis) has been reported in wheat fields of eastern China. To better understand the distribution of the resistant populations and the occurrence of the target-site mutations, 74 populations collected from Anhui, Jiangsu and Shandong province were surveyed, and the ACCase and ALS gene fragments, encompassing all the documented mutant codon positions, were amplified and sequenced. Plants from 37 and 34 populations survived fenoxaprop-P-ethyl and mesosulfuron-methyl treatment at 62.1 g a.i. ha-1 and 9 g a.i. ha-1 respectively, with different survival rates. Twenty-seven populations exhibited multiple resistance to fenoxaprop-P-ethyl and mesosulfuron-methyl. Whole-plant dose-response experiments showed that the resistance index ranged from 6.2 to 167.8 for fenoxaprop-P-ethyl, and from 7.8 to 139.5 for mesosulfuron-methyl. Four ACCase (I1781L, I2041N, I2041T and D2078G) and four ALS (P197R, P197S, P197T and W574 L) resistance mutations were detected respectively. Individuals containing two amino acid substitutions were also found. D2078G and W574 L were predominant ACCase and ALS gene mutations respectively. This study has shown that fenoxaprop-P-ethyl and mesosulfuron-methyl resistance was prevalent in A. aequalis in eastern China, and target site mutations in the ACCase and ALS gene were one of the most common mechanisms.

Correlation between chronic headaches and the rectus capitis posterior minor muscle: A comparative analysis of cross-sectional trail.

Objective We aimed to investigate the morphological changes and potential correlation between chronic headaches and the rectus capitis posterior minor muscle (RCPmi). Methods Comparison of RCPmi between patients with chronic headaches and healthy adult volunteers were collected using magnetic resonance imaging (MRI) and Mimics software. Results Among the 235 MRI images analyzed, the data between the two groups were considered statistically significant. The number of males was larger than that of females ( p < 0.001) and the headache group showed greater hypertrophy than the control group in both males ( p < 0.001) and females ( p = 0.001). Conclusions Chronic headaches were correlated with the RCPmi. Patients with chronic headaches suffered from more obvious hypertrophy than that of the control group. Additionally, it was supposed that RCPmi hypertrophy may be one pathogenesis of the chronic headaches.

The error analysis of Lobular and segmental division of right liver by volume measurement.

The aim of this study is to explore the inconsistencies between right liver volume as measured by imaging and the actual anatomical appearance of the right lobe. Five healthy donated livers were studied. The liver slices were obtained with hepatic segments multicolor-infused through the portal vein. In the slices, the lobes were divided by two methods: radiological landmarks and real anatomical boundaries. The areas of the right anterior lobe (RAL) and right posterior lobe (RPL) on each slice were measured using Photoshop CS5 and AutoCAD, and the volumes of the two lobes were calculated. There was no statistically significant difference between the volumes of the RAL or RPL as measured by the radiological landmarks (RL) and anatomical boundaries (AB) methods. However, the curves of the square error value of the RAL and RPL measured using CT showed that the three lowest points were at the cranial, intermediate, and caudal levels. The U- or V-shaped curves of the square error rate of the RAL and RPL revealed that the lowest value is at the intermediate level and the highest at the cranial and caudal levels. On CT images, less accurate landmarks were used to divide the RAL and RPL at the cranial and caudal layers. The measured volumes of hepatic segments VIII and VI would be less than their true values, and the measured volumes of hepatic segments VII and V would be greater than their true values, according to radiological landmarks. Clin. Anat. 30:585-590, 2017. © 2017 Wiley Periodicals, Inc.

Comparison of Two Acute Toxicity Test Methods for the Silkworm (Lepidoptera: Bombycidae).

Silkworm (Bombyx mori) is an economically important insect and an ideal nontarget organism to study the environmental assessment of pesticides. Two acute toxicity test methods, leaf-dipping and quantitative spraying, with five insecticides, were compared for pesticide risk assessment. Based on LC50 values of these insecticides by both methods, the order of toxicity levels of five insecticides tested against silkworm was as follows: emamectin benzoate>lambda-cyhalothrin>imidacloprid>chlorpyrifos>dimethoate. Means of relative confidence interval values for individual insecticides of leaf-dipping and quantitative spraying method were-emamectin benzoate (22.55 and 19.03%), lambda-cyhalothrin (18.03 and 17.71%), imidacloprid (19.21 and 16.96%), chlorpyrifos (17.20 and 15.97%), and dimethoate (17.78 and 15.81%). The coefficient of variation values were-emamectin benzoate (17.74 and 5.44%), lambda-cyhalothrin (21.15 and 5.16%), imidacloprid (13.01 and 5.65%), chlorpyrifos (16.72 and 4.85%), and dimethoate (28.36 and 7.93%). The results of the study show that the quantitative spraying method is more effective than the leaf-dipping method in precision and reproducibility. The results of this study will offer a useful reference for selecting a more scientific and rational method for pesticide risk assessment.

Identification and characterization of circadian clock genes in the head transcriptome of Conopomorpha sinensis Bradley.

Conopomorpha sinensis Bradley is the most detrimental pest to litchi and longan in China. Adult eclosion, locomotion, mating and oviposition of C. sinensis usually occur at night, regulated by a circadian rhythm. Nevertheless, our understanding of the linkages between adult circadian rhythms and clock genes remains inadequate. To address this gap, transcriptomic analysis was conducted on female and male heads (including antennae) of C. sinensis using the Illumina HiSeq 6000 platform to identify major circadian clock-related genes. The annotated sequences were analyzed by BLASTx, and candidate clock genes were classified based on conservation, predicted domain architectures, and phylogenetic analysis. The analysis revealed a higher conservation of these genes among the compared moths. Further, the expression profile analysis showed a significant spatiotemporal and circadian rhythmic accumulation of some clock genes during development. The candidate clock genes were predominantly expressed in the head, highlighting their crucial function in circadian rhythm regulation. Moreover, CsinPer, CsinTim1, and CsinCry1 displayed similar dynamic expressions with a peak expression level in the 4th age adults, suggesting their involvement in regulation of courtship and mating behaviors. The CsinPer and CsinTim1 mRNA oscillated strongly with a similar phase, containing a peak expression just before the female mating peak. This work will greatly contribute to understanding the circadian clock system of C. sinensis and provide valuable information for further studies of the molecular mechanisms involved in rhythmicity in fruit-boring pests.

Evidence for chronic headaches induced by pathological changes of myodural bridge complex.

Clinical studies have shown that there may be a certain relationship between pathological changes of the myodural bridge complex (MDBC) and chronic headaches of unknown cause. But there is still a lack of experimental evidence to explain the possible mechanism. This study aims to further confirm this relationship between MDBC and chronic headaches and explore its potential occurrence mechanism in rats. Bleomycin (BLM) or phosphate-buffered saline (PBS) was injected into the myodural bridge fibers of rats to establish the hyperplastic model of MDBC. After 4 weeks, the occurrence of headaches in rats was evaluated through behavioral scores. The immunohistochemistry staining method was applied to observe the expression levels of headache-related neurotransmitters in the brain. Masson trichrome staining results showed that the number of collagen fibers of MDBC was increased in the BLM group compared to those of the other two groups. It revealed hyperplastic changes of MDBC. The behavioral scores of the BLM group were significantly higher than those of the PBS group and the blank control group. Meanwhile, expression levels of CGRP and 5-HT in the headache-related nuclei of the brain were increased in the BLM group. The current study further confirms the view that there is a relationship between pathological changes of MDBC and chronic headaches of unknown cause. This study may provide anatomical and physiological explanations for the pathogenesis of some chronic headaches of unknown cause.

The VP37-binding protein F1ATP synthase ß subunit involved in WSSV infection in shrimp Litopenaeus vannamei.

To investigate the interaction between white spot syndrome virus (WSSV)-VP37 and gill membrane proteins (GMPs) of Pacific white shrimp (Litopenaeus vannamei), the VP37 protein was expressed and purified, and a distinct 53 kDa VP37-binding protein band was identified in GMPs by virus overlay protein binding assay and GST pull-down assay. By electroelution, the VP37 binding protein was purified and identified as F(1)ATP synthase ß (F(1)ATPase ß) subunit by Mass Spectrometry. The purified F(1)ATPase ß subunit was used to immunize BALB/C mice to produce monoclonal antibodies (Mabs). After cell fusion, sixteen hybridomas secreting Mabs against F(1)ATPase ß subunit of L. vannamei were screened by enzyme-linked immunosorbant assay (ELISA), three of which designated as 1D5, 1E8 and 2H4 were cloned by limiting dilution and further characterized by indirect immunofluorescence assay (IIFA) and western blotting. The results of IIFA showed that specific fluorescence signals located at the peripheral zone of the gills of L. vannamei. Western blotting demonstrated that three Mabs reacted specifically with the 53 kDa protein band in GMPs of L. vannamei. By IIFA, the Mabs could also cross-react with the gill cells of three other WSSV-susceptible shrimps Fenneropenaeus chinensis, Penaeus monodon and Marsupenaeus japonicus. Furthermore, the three anti-F(1)ATPase ß subunit Mabs could partially block the binding of WSSV to GMPs by ELISA in vitro, and also exhibited direct anti-WSSV activity in shrimp by neutralization assay in vivo. These findings suggested that F(1)ATPase ß subunit involved in WSSV infection in L. vannamei.

The relationship between compensatory hyperplasia of the myodural bridge complex and reduced compliance of the various structures within the cranio-cervical junction.

The myodural bridge complex (MDBC) is described as a functional anatomic structure that involves the dense connective tissue fibers, muscles, and ligaments in the suboccipital region. It has recently been proposed that the MDBC can influence cerebrospinal fluid (CSF) circulation. In the present study, bleomycin (BLM), a type of antibiotic that is poisonous to cells, was injected into the posterior atlanto-occipital interspace (PAOiS) of rats to induce fibrous hyperplasia of structures in PAOiS. Sagittal sections of tissues obtained from the posterior-occipital region of the rats were stained utilizing the Masson Trichrome staining method. Semiquantitative analysis evidenced that the collagen volume fraction of collagen fibers of the MDBC, as well as the sum of the area of the spinal dura mater and the posterior atlanto-occipital membrane in the BLM group were significantly increased (p < .05) compared to that of the other groups. This finding illustrates that the MDBC fibers as well as other tissues in the PAOiS of rats in the BLM group developed fibrotic changes which reduced compliance of the spinal dura mater. Indeed, the sectional area of the rectus capitis dorsal minor muscle in the BLM group was measured to be increased. These changes may further restrict CSF flow. The present research provides support for the recent hypothesis proposed by Labuda et al. concerning the pathophysiology observed in symptomatic adult Chiari malformation Type I patients, that there exists a relationship between the altered compliance of the anatomic structures within the craniocervical region and the resultant compensatory hyperplasia of the MDBC.

A valuable subarachnoid space named the occipito-atlantal cistern.

The cisterna magna has been defined as the space between the inferior margin of the cerebellar vermis to the level of the foramen magnum, while an enlarged dorsal subarachnoid space at the occipito-cervical junction extending from the foramen magnum to the upper border of the axis (C2) is still ignored. Recently, the myodural bridge complex is proved to drive the cerebral spinal fluid flowing via this region, we therefore introduce the "occipito-atlantal cistern (OAC)" to better describe the subarachnoid space and provide a detailed rationale. The present study utilized several methods, including MRI, gross anatomical dissection, P45 sheet plastination, and three-dimensional visualization. OAC was observed to be an enlarge subarachnoid space, extending from the foramen magnum to the level of the C2. In the median sagittal plane, OAC was a funnel shape and its anteroposterior dimensions were 15.92 ± 4.20 mm at the level of the C0, 4.49 ± 1.25 mm at the level of the posterior arch of the C1, and 2.88 ± 0.77 mm at the level of the arch of the C2, respectively. In the median sagittal plane, the spino-dural angle of the OAC was calculated to be 35.10 ± 6.91°, and the area of OAC was calculated to be 232.28 ± 71.02 mm2. The present study provides OAC is a subarachnoid space independent from the cisterna magna. Because of its distinctive anatomy, as well as theoretical and clinical significance, OAC deserves its own name.

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.

Impacts of Land Use on Surface Water Quality Using Self-Organizing Map in Middle Region of the Yellow River Basin, China.

The Yellow River is one of the most important water sources in China, and its surrounding land use affected by human activities is an important factor in water quality pollution. To understand the impact of land use types on water quality in the Sanmenxia section of the Yellow River, the water quality index (WQI) was used to evaluate the water quality. A self-organizing map (SOM) was used for clustering analysis of water quality indicators, and the relationship between surface water quality and land use types was further analyzed by redundancy analysis (RDA). The results showed that WQI values ranged from 82.60 to 507.27, and the highest value was the sampling site S3, whose water quality grade was "Likely not suitable for drinking", mainly polluted by agricultural non-point sources ammonia nitrogen pollution. SOM clustered the sampling sites into 4 groups according to the water quality indicators, the main influencing factors for different groups were analyzed and explored in more depth in relation to land use types, suggesting that surface water quality was significantly connected with the proportion of land use types at the watershed scale in the interpretation of water quality change. The negative impact of cropland on surface water quality was greater than that of other land use types, and vegetation showed a greater positive impact on surface water quality than other land uses. The results provide evidence for water environment conservation based on land use in the watershed.