[Factors Influencing the Variation in Phytoplankton Functional Groups in Fuchunjiang Reservoir].

To explore the distribution characteristics, blooming risk mechanism and driving factors of phytoplankton community structure in Fuchunjiang Reservoir. The variation characteristics of phytoplankton, zooplankton and physicochemical indicators in Fuchunjiang Reservoir and its upper and lower reaches were investigated in 2020 and 2021. Based on the phytoplankton functional groups, non-metric multidimensional scale analysis, redundancy analysis and other statistical methods, the seasonal succession characteristics and driving factors of phytoplankton functional groups were analyzed. A total of 18 phytoplankton functional groups were identified, in of which 10 were predominant. The composition of phytoplankton functional groups in the Fuchunjiang Reservoir was significant different. Spatially, the upstream were dominated by group C and P while the represent species were Cyclotella and Aulacoseira,reflecting the mixed meso-eutrophic environments. However, group P was the main group in Fuchunjiang reservoir, and the dominance decreased gradually along the stream direction. Meanwhile, in the downstream, MP has an absolute advantage at Qiantang River estuary. It reflected the environmental characteristics of frequent disturbance and high turbidity of tide-sensing rivers. In addition, the predominant functional groups demonstrated strong seasonal variations. The dominant functional groups were diverse in summer and consisted of P+L0+J+M+S1+H1+MP. In addition to group P (Aulacoseira), which was dominant throughout the year, it also included several groups represented by cyanobacteria and chlorophyta, reflecting the environmental characteristics of changeable habitats and vigorous productivity. In autumn, the succession was dominated by H1 group represented by Dolichospermum and the representative function groups were P and H1, reflecting the hydrological background of reduced flow and static flow. In winter, the increase of Cyclotella led to the predominance of group C, which was dominated by P+C, reflecting the changing conditions of weakened water exchange and intensified eutrophication problems. In spring, the dominant functional groups were gradually enriched and were composed of C, D, P, and MP, which also reflected the changing environmental habitat characteristics which caused by increasing rainfall and air temperature. According to the results of the C-R-S growth strategy, the Fuchunjiang Reservoir has been in the R strategy for a long time, which was consistent with the habitat characteristics of Fuchunjiang Reservoir and its upper and lower reaches with high disturbance and low stress. In addition, C strategy and S strategy appeared in some reaches, reflecting the variability of water quality and hydrology. RDA analysis showed that water temperature, discharge, zooplankton biomass, permanganate index, total nitrogen and total phosphorus were significantly correlated with the seasonal succession of phytoplankton functional groups (P < 0.05), and temperature and flow pattern were probably the most critical factors for the succession. Studies have shown that the impact of hydrometeorological processes on phytoplankton in the Fuchunjiang Reservoir is crucial:high temperature and changing discharge during the summer may lead to cyanobacterial blooms in the Fuchunjiang reservoir; To reduce the risk of algal blooms, it is still necessary to increase the control of nitrogen and phosphorus load in rivers, and fully consider the coordination of water conservancy dispatch methods.

Hypso- or bathochromic phosphorescent mechanochromic mononuclear Cu(I) complexes with a bis(2-diphenylphosphinophenyl)ether auxiliary ligand.

Six phosphorescence-emitting metal-organic mononuclear Cu(I) complexes, namely four quinoline-containing three-coordinate Cu(I) complexes and two N-heterocyclic carbene-containing four-coordinate Cu(I) complexes, have been successfully developed and fully characterized. All these Cu(I) complexes include the same bis(2-diphenylphosphinophenyl)ether bidentate auxiliary ligand. Significantly, four-coordinate Cu(I) complexes 1 and 2 display typical aggregation-induced emission phenomena. Their solid samples of luminogenic complexes 1-6 emit a variety of different phosphorescence. Furthermore, solid-state phosphorescence of these Cu(I) complexes can be effectively manipulated by external mechanical force. Remarkably, luminophores 1, 2 and 5 exhibit blue-shifted mechanoluminochromism responses, while luminophores 3, 4 and 6 present red-shifted mechanoluminochromism characteristics. All of the observed mechano-responsive phosphorescence changes of solids 1-6 are reversible by the method of solvent fuming. Powder X-ray diffraction results confirm that the reversible mechanically induced phosphorescence changes of complexes 1-6 are due to the mutual transformation of ordered crystalline and metastable amorphous states.

Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method for Sensitive Analysis of Residual Protein Tat Bh1-101 in Lentiviral Vectors for Gene Therapy.

Lentiviral (LV) vector-based gene therapy is gaining popularity for treating a wide range of diseases. Various LV vectors are being developed for transducing cells in cellular gene therapy at St. Jude. Some LV vectors are produced using stable 293T packaging cell lines, which includes gag-pol-rev-tat and virus-glycoprotein. Transactivating factor (transactivator of transcription [Tat]) is a regulatory protein that drastically increases the efficiency of lentiviral transcription. Residual analysis of Tat is critical for gene vector quality and safety. In this work, we developed a highly sensitive liquid chromatography-tandem mass spectrometry method for analysis of residual Tat in Lentivirus as an alternative to enzyme-linked immunosorbent assay. Residual Tat in LV can be accurately quantified with high specificity with a limit of detection of 0.3 ng/mL.

[Vertical Distribution Characteristics and Influencing Factors of Phytoplankton Community Structure in Qiandao Lake].

Clear vertical variations in phytoplankton community structure are usually observed in deep-water lakes and reservoirs, which is one of the key components of water quality and ecosystem functioning. However, the vertical patterns and ecological drivers of phytoplankton communities in deep-water lakes and reservoirs are still understudied. In this study, we took Qiandao Lake, a deep-water reservoir, as an example to reveal the vertical distribution characteristics of phytoplankton communities and its influencing factors by investigating phytoplankton community structure and the associated water quality index at 12 sites across the whole lake in two seasons (spring and autumn). The results showed that the phytoplankton abundance and chlorophyll a were highest in the surface layer in autumn and then decreased toward deep water, whereas in spring, the maximum value occurred in the subsurface layer (2-5 m), and the dominant phytoplankton species showed obvious vertical stratification characteristics. Specifically, in spring, Cryptomonas and Pseudanabaena dominated the surface and subsurface layers, Cryptomonas dominated in the middle layer, and the abundance of Cyclotella at the bottom layer was significantly higher than that of the other algae genera. The dominant genera in autumn were Pseudanabaena and Aphanizomenon. In the subsurface and middle layers, Leptolyngbya and Pseudanabaena occupied the dominant position, and Leptolyngbya became the only dominant genus. In the bottom layer, Leptolyngbya was the only dominant genus. The key environmental indicators of the water also had obvious vertical changes. The contents of N and P nutrients had a negative correlation with the water depth in spring, whereas the reverse trend was observed in autumn. The correlation analysis showed that the vertical variation in phytoplankton abundance in spring was significantly positively correlated with phosphate concentration, whereas the vertical distribution of phytoplankton abundance in autumn was significantly positively correlated with intensity of light, and the water temperature, NH4+-N, and total nitrogen were the main factors driving the vertical changes in the dominant genera of phytoplankton community in the two seasons. To summarize, environmental conditions such as water temperature, light, and nutrients had strong effects on the vertical distribution of phytoplankton. In the ecological investigation and quality assessment of deep-water lakes and reservoirs, the vertical distribution characteristics of the phytoplankton community structure and the influence of environmental conditions should be fully considered.

Multimodal therapy strategies based on hydrogels for the repair of spinal cord injury.

Spinal cord injury (SCI) is a serious traumatic disease of the central nervous system, which can give rise to the loss of motor and sensory function. Due to its complex pathological mechanism, the treatment of this disease still faces a huge challenge. Hydrogels with good biocompatibility and biodegradability can well imitate the extracellular matrix in the microenvironment of spinal cord. Hydrogels have been regarded as promising SCI repair material in recent years and continuous studies have confirmed that hydrogel-based therapy can effectively eliminate inflammation and promote spinal cord repair and regeneration to improve SCI. In this review, hydrogel-based multimodal therapeutic strategies to repair SCI are provided, and a combination of hydrogel scaffolds and other therapeutic modalities are discussed, with particular emphasis on the repair mechanism of SCI.

Synthesis and characterization of ionic liquid microneedle patches with different carbon chain lengths for antibacterial application.

The prevention of bacterial infection is becoming more and more important in clinical medicine. Ionic liquids (ILs) can change the structure in an almost infinite way to actively antagonize pathogenic microorganism strains. The current biological materials of skin dressings inevitably have the shortcomings of single drug delivery form and low drug loading, which limit the practical application of skin dressings. Therefore, it is particularly important to develop drug delivery forms that can meet different conditions. The addition of ILs into crosslinked microneedle (MN) patches is a novel design scheme of MNs. The broad-spectrum antibacterial properties of imidazolium salt ILs ensure that the wound skin is sterile after the use of MN patches on the skin to open channels for drug delivery. In this study, imidazole IL monomers with different carbon chain lengths and the corresponding IL-MN patches were designed and synthesized. By comparing the antibacterial properties of four imidazolium salt IL monomers with different carbon chain lengths and the corresponding ionic liquid microneedle patches, we found that the antibacterial properties of IL monomers and IL-MN patches increased with the increase of substituent carbon chain lengths. Imidazole IL monomers have excellent antibacterial properties, which may be caused by the electrostatic interaction between the cations in the IL monomers and the anions in the bacterial membrane and the hydrophilic and hydrophobic interactions between the IL monomers.

The switch of DNA states filtering the extrinsic noise in the system of frequency modulation.

There is a special node, which the large noise of the upstream element may not always lead to a broad distribution of downstream elements. This node is DNA, with upstream element TF and downstream elements mRNA and proteins. By applying the stochastic simulation algorithm (SSA) on gene circuits inspired by the fim operon in Escherichia coli, we found that cells exchanged the distribution of the upstream transcription factor (TF) for the transitional frequency of DNA. Then cells do an inverse transform, which exchanges the transitional frequency of DNA for the distribution of downstream products. Due to this special feature, DNA in the system of frequency modulation is able to reset the noise. By probability generating function, we know the ranges of parameter values that grant such an interesting phenomenon.

The common misuse of noise decomposition as applied to genetic systems.

The noise-decomposition technique is applied in several fields, including genetic systems, optical images, recording, and navigation. In genetic systems, noise decomposition is usually achieved by using two reporters [Elowitz M.B., Levine A.J., Siggia E.D., Swain P·S., 2002. Stochastic gene expression in a single cell. Science 297, 1183-6.]. A reporter is a protein with fluorescence, an RNA hybridized with a fluorescent probe, or any other detectable intracellular component. If a reporter is constructed in addition to the original reporter, the system's stochasticity may change. Such phenomena became severe for genes in plasmids with a high copy number. By SSA (stochastic simulation algorithm), we observed an approximately 50% increment in the coefficient of variation while introducing additional reporters. Besides, if two reporters respond to the upstream element at a different time, the trunk noise (or extrinsic noise) cannot be accurately determined. This is because the "calculative trunk noise" changes along with the delay, though the real trunk noise does not. For RNA reporters, a 5-min transcriptional delay caused a calculative trunk noise that was 90% less than the real trunk noise. Fortunately, this problem is negligible when the degradation rate constant is low, and it is usually true in the case of the protein reporters. One can check the lifespan of the reporter before applying the noise-decomposition technique.

A Practicable Method of Tuning the Noise Intensity at Protein Level.

The expression of genes is inevitably subject to intracellular noise. Noise, for some regulatory networks, is constructive but detrimental to many others. The intensity of the noise is a determinant factor and the method of tuning it is of great value. In this study, we illustrated that the transcriptional delay in an incoherent feedforward loop (FFL) grants the target protein modulation the intensity of noise. Remarkably, for a wide range, the coefficient of variation (COV) of the target protein appeared to be about linear to the time span of the transcriptional delay. Without a noise-buffering method, the COV of the target protein is 0.455. While applying incoherent FFL, the COV reduced to 0.236. Then, it changed from 0.236 to 0.630 as the transcriptional delay raised from 0 to 1000 seconds. If we further increased the delay out of the linear range, the COV finally reached 0.779. In addition, we incorporated the distribution of the transcriptional delay in the delay stochastic simulation algorithm. This distribution is based on the experimental observation in the literature. The outcome suggested that the distributed delay slightly improved the ability of tuning noise. In conclusion, we demonstrated a noise-tuning method that altered only the intensity of noise without changing the deterministic steady-state behaviors. It is ready to be applied to various systems in the field of synthetic biology.

Exposure to One Antibiotic Leads to Acquisition of Resistance to Another Antibiotic via Quorum Sensing Mechanisms.

The vancomycin-resistant Enterococci (VRE) have progressively become a severe medical problem. Although clinics have started to reduce vancomycin prescription, vancomycin resistance has not been contained. We found that the transfer of vancomycin resistance in Enterococcus faecalis increased more than 30-fold upon treatment by streptomycin. Notably, treatment with an antibiotic caused the bacteria to become resistant to another. The response was even stronger in the well-studied plasmid pCF10 and the number of transconjugants increased about 100,000-fold. We tested four different antibiotics, and all of them induced conjugal response. Through a mathematical model based on gene regulation, we found a plausible explanation. Via quorum sensing, the change of the cell density triggers the conjugation. Moreover, we searched for generality and found a similar strategy in Bacillus subtilis. The outcome of the present study suggests that even common antibiotics must not be overused.

Highly Sensitive SDS Capillary Gel Electrophoresis with Sample Stacking Requiring Only Nanograms of Adeno-Associated Virus Capsid Proteins.

Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) has been the method of choice in the past decades for size-based protein analysis. However, in general it requires the protein concentration in mg/mL level and thus is not practical for trace level protein analysis, not to mention the lengthy labor-intensive procedures. The SDS capillary gel electrophoresis (SDS CGE) method reported herein requires only nanogram-sized proteins loaded onto the autosampler. A sample stacking technique (e.g., head-column field-amplified sample stacking (HC FASS)) was employed, providing three orders of magnitude sensitivity enhancement compared to conventional SDS CGE. This method has been used routinely in purity analysis and characterization of adeno-associated virus (AAV) intermediates and finished gene therapeutics of AAV vectors. The sensitivity achieved is comparable to the currently most sensitive size-based protein assay silver-stained SDS PAGE. The highly sensitive sample stacking SDS CGE can be used for other types of proteins as well.

[Effects of Hydrological and Meteorological Conditions on Diatom Proliferation in Reservoirs].

The proliferation of diatoms is an ecological disaster that harms the water quality of many reservoirs in China. In order to reveal the driving factors of abnormal algal blooms in reservoirs, phytoplankton community structure and the associated environmental factors from 2009 to 2016 from Shahe Reservoir in Tianmuhu were analyzed. Results showed that diatoms and there dominant genus were predominately driven by temperature, and the relationship between hydrology and nutrition was insignificant. Distinct relationships were recorded between different diatom genera and temperature over the past eight years. The optimum growth temperature of diatoms and Synedra were both 27℃, while that for Cyclotella and Achnanthes were both 19℃. Low temperature was suitable for the growth of Melosira, and its growth was compromised with increasing temperature. In a multivariable statistical analysis of the dominant diatom genus and the associated environmental factors, we found that the dominant diatom genus responded differently to the associated environmental factors. The total biomass of the diatom and the biomass of Synedra and Achnanthes were significantly and positively correlated with rainfall (P<0.05). The biomass of Cyclotella was significantly and positively correlated with total phosphorus, rainfall, and water level (P<0.05) and significantly and negatively correlated with water exchange rate (P<0.05). The biomass of Melosira was significantly and positively correlated with total phosphorus. The annual peak biomass of diatoms can be predicted by a multiple regression model with independent variables, including rainfall intensity, dissolved total phosphorus, and the accumulated temperature in winter and spring. Our results indicated that the proliferation of diatoms responds significantly to hydrological and meteorological factors while insignificantly to nitrogen and phosphorus loading. External load reduction is needed to maintain a good water quality in the reservoir. In addition, extreme weather conditions should be given attention to provide an early warning for diatom proliferation.

[Thermal Stratification and Its Impacts on Water Quality in Shahe Reservoir, Liyang, China].

Based on the one-year hourly water temperature profiles and the associated environmental drivers during the past eight years in Shahe Reservoir, Jiangsu Province, China from 2009 to 2016, the factors underlying the seasonal variation of thermal stratification and water quality response were investigated. It was shown that the thermal stratification was a typical subtropical one-cycle mixing model, lasting from May to September. The thermal stratification appeared and disappeared when the surface water temperature was 21 ℃ in the late spring and 19 ℃ in the middle of autumn. The difference between the water temperature at the epilimnion and hypolimnion increased with increasing solar radiation. When the air temperature was above 30 ℃, the stability of the thermal stratification increased. Heavy storms reduced the temperature of the surface water and weakened the temperature stratification of the column above a 5 m depth but had limited impact on the stratification of the hypolimnion deeper than 5 m. The thermal stratification greatly impacted the water quality of the lake. Hypoxia in the bottom water occurred by thermal stratification, leading to increased NH4+-N. The concentrations of dissolved oxygen, total phosphorus, and suspended solids in the hypolimnion increased after the disappearance of thermal stratification. Our results indicated that the thermal stratification was mainly controlled by solar radiation and the thermal stratification favored the growth of cyanobacteria and led to the release of nutrients from the sediment, threatening the water quality. Attention should be paid to thermal stratification to prevent algal blooms and related water quality deterioration.

Sample Stacking Provides Three Orders of Magnitude Sensitivity Enhancement in SDS Capillary Gel Electrophoresis of Adeno-Associated Virus Capsid Proteins.

Size-based protein analysis utilizing only 25 ng of total proteins has been realized by sodium dodecyl sulfate capillary gel electrophoresis (SDS CGE) with head-column field-amplified sample stacking as an online sample preconcentration technique. This method has been used as a replacement of SDS-PAGE for purity analysis of adeno-associated virus (AAV) therapeutic products of different serotypes and transgenes. A limit of detection of 0.2 ng/mL (3.3 pM) capsid proteins was achieved with convenient UV absorbance detection at 214 nm, equivalent to 20 pg of protein (330 attomole) loaded in the autosampler vial. For purity analysis, only 25 ng of total AAV capsid proteins (4.3 femtomole virus particles) were loaded to the autosampler vial. The sensitivity is comparable to silver-stained SDS-PAGE. The RSD of purity measurement was 0.0-0.8%, comparable to conventional SDS CGE utilizing 0.1-0.5 mg proteins. The new method provided 3 orders of magnitude sensitivity enhancement as compared to conventional SDS CGE. It shares all the advantages of conventional SDS CGE (labor-saving, easy automation, and convenient quantitation) and also the high sensitivity of silver stained SDS-PAGE. The sample stacking SDS CGE technique can be adopted for size-based analysis of other types of proteins. It is especially useful when protein quantity or concentration is not sufficient for regular SDS CGE or SDS-PAGE assay.

[Spatio-temporal Variations in Phytoplankton Community in Shahe Reservoir, Tianmuhu, China].

Monthly investigations of the phytoplankton community and the associated environmental drivers during the past eight years in the Shahe Reservoir, Jiangsu Province, China revealed the spatial and temporal variations of phytoplankton and the associated driving factors in the reservoir. The results show that the concentrations of total nitrogen (TN), total phosphorous (TP), turbidity (Turb), suspended solids (SS), and chlorophyll-a (CHL) were the highest in the upstream tributaries and the lowest in the downstream-linked reservoir. In contrast, the highest Secchi disk depth (SDD) was recorded in the Shahe Reservoir and that the lowest in the upstream tributaries. Significant differences in water quality indices were recorded among the upstream tributaries, the transition region, and the downstream-linked reservoir area (ANOVA, P<0.05). The biomass of phytoplankton was the highest in the upstream tributaries and the lowest in the reservoir. The highest biomass of phytoplankton was recorded in the summer and the lowest in the winter. Synedra, Cyclotella, Cryptomonas, and Achnanthes were the dominant genera in the spring; Synedra, Cryptomonas, Raphidiopsis, and Phormidium were dominant in the summer; Cryptomonas, Synedra, Raphidiopsis, and Aphanizomenon were dominant in the autumn; and Cryptomonas, Synedra, Achnanthes, and Cyclotella were dominant in the winter. Synedra and Cryptomonas were the dominant genera throughout the year. The correlation analysis shows that TP, water temperature, and SDD were the most important driving factors for the spatial and temporal variations of phytoplankton. Notable spatial differences were recorded for Cryptomonas, while minimal variations were recorded for the remaining species. A smaller number sampling sites and a higher sampling frequency are needed to characterize the phytoplankton community in the Shahe Reservoir.

Novel biomarkers for diagnosis and precision treatment of pulmonary arterial hypertension / 药物评价研究

Pulmonary arterial hypertension is characterized by elevated pulmonary arterial pressure with high disabled rate and lethality.Since many causes could lead to pulmonary arterial hypertension,the mechanism studies were developed rapidly,and some new therapeutic targets have been explored according to the multiple pathogenic mechanisms and pathways.We summarized the potential and novel biomarkers of the mechanisms associated with pulmonary arterial hypertension,and categorized based on their relationship to endothelial cell dysfunction,inflammation,epigenetics,cardiac function,oxidative stress,extracellular matrix,etc.The biomarkers can help for diagnosis,sorting,disease severity assessment of PAH,in order to provide the basis for precision treatment and new therapeutic target development.

Correction: Serum- and Glucocorticoid-Inducible Kinase-1 (SGK-1) Plays a Role in Membrane Trafficking in Caenorhabditis elegans.

[This corrects the article DOI: 10.1371/journal.pone.0130778.].

The Role of Nerve Growth Factor in Ginsenoside Rg1-Induced Regeneration of Injured Rat Sciatic Nerve.

Sciatic nerve injury is commonly seen in clinical practice predominantly associated with trauma or sports injuries. Recent studies indicated that ginsenoside Rg1 (Gs Rg1), extracted from Chinese herbs, was found to promote regeneration of injured rat sciatic nerve and that nerve growth factor (NGF) may be involved in this process. The aim of this study was to examine the role that NGF may play in ginsenoside Rg1-induced regeneration of rat sciatic nerve following injury. Animals following surgical right sciatic nerve injury were subsequently administered intraperitoneally either saline (sham control) or different doses of 2, 4, 8, or 12 mg/kg daily GsRg1 for 2 to 8 wk. In addition, 100 µg/kg mecobalamin, a drug utilized to treat nerve injuries, was employed as a positive control. After 2, 4, or 8 wk, sciatic functional index (SFI) and mean nerve conduction velocity (MNCV), markers of sciatic nerve function, were assessed to determine whether recovery of injured sciatic nerve occurred. In addition, immunohistochemistry and Western blot methods were used to examine NGF protein expression changes. Results showed that all doses of GsRg1 significantly increased SFI and MNCV in injured sciatic-nerve-damaged rats in a manner similar to that noted with mecobalamin. It is of interest that the intermediate 4- and 8-mg/kg doses were more effective in restoring nerve functions. Immunohistochemistry and Western blot results also demonstrated a similar pattern with enhanced NGF protein expression at all doses, but greater effects were noted at 4 and 8 mg/kg GsRg1. Data suggest that GsRg1 promotes recovery of injured sciatic nerve functions within a specific dose range and that NGF may be involved in this physiological process.

Serum- and Glucocorticoid-Inducible Kinase-1 (SGK-1) Plays a Role in Membrane Trafficking in Caenorhabditis elegans.

The mammalian serum- and glucocorticoid-inducible kinase SGK1 regulates the endocytosis of ion channels. Here we report that in C. elegans sgk-1 null mutants, GFP-tagged MIG-14/Wntless, the sorting receptor of Wnt, failed to localize to the basolateral membrane of intestinal cells; instead, it was mis-sorted to lysosomes. This effect can be explained in part by altered sphingolipid levels, because reducing glucosylceramide biosynthesis restored the localization of MIG-14::GFP. Membrane traffic was not perturbed in general, as no obvious morphological defects were detected for early endosomes, the Golgi apparatus, and the endoplasmic reticulum (ER) in sgk-1 null animals. The recycling of MIG-14/Wntless through the Golgi might be partially responsible for the observed phenotype because the subcellular distribution of two plasma membrane cargoes that do not recycle through the trans-Golgi network (TGN) was affected to a lesser degree. Consistently, knockdown of the ArfGEF gbf-1 altered the distribution of SGK-1 at the basolateral membrane of intestinal cells. In addition, we found that sgk-1(RNAi) induced unfolded protein response in the ER, suggesting at least an indirect role of SGK-1 early in the secretory pathway. We propose that SGK-1 function is required for lipid homeostasis and that it acts at different intracellular trafficking steps.

Multiple occipital defects caused by arachnoid granulations: Emphasis on T2 mapping.

A 56-year-old man presented with a 6-mo history of headache. Although neurological and laboratory examinations were normal, computed tomography (CT) scan was performed which revealed multiple occipital osteolytic lesions, which were suspected to be multiple myeloma. Subsequently nuclear magnetic resonance imaging (MRI) showed that these lesions presented with a cerebrospinal fluid (CSF)-like signal intensity, no diffusional restriction and intrinsic mass-like enhancement on conventional sequences were seen. T2 relaxation time was similar to that of CSF in the ventricles and adjacent subarachnoid space on T2-mapping. Single photon emission CT with (99m)Tc-Methyl diphosphonate was performed which revealed no increased radiotracing accumulation. Finally, these lesions were diagnosed as mutiple arachnoid granulations (AGs). The headache was treated symptomatically with medical therapy. On follow up examination after 6 mo no evidence of tumor was detected. This report aimed to illustrate the appearance and differentiation of occipital defects caused by multiple AGs on CT and MRI, with emphasis on the findings from T2 mapping.