Background
Preoperative evaluation of the consistency of pituitary macroadenomas is important for neurosurgeons to prepare the surgical plan.
Purpose
To evaluate the diagnostic performance of texture ...analysis (TA) of diffusion‐weighted imaging (DWI) at a standard b‐value (b = 1000 s/mm2) and a high b‐value (b = 2000 s/mm2) for their ability to assess the tumor consistency of pituitary macroadenomas.
Study Type
Retrospective.
Population/Subjects
Fifty patients with histologically confirmed pituitary macroadenomas were classified as soft (n = 37) or hard (n = 13) types.
Field Strength/Sequence
Coronal T2‐weighted imaging (T2WI), Readout Segmentation of Long Variable Echo‐trains (RESOLVE) DWI at b = 1000 s/mm2 and b = 2000 s/mm2 were acquired with 3.0T MRI.
Assessment
The corresponding apparent diffusion coefficient (ADC) maps (ADC1000 and ADC2000) were registered to T2WI. Regions of interest (ROIs) were manually drawn along the solid part of the tumor from the coregistered T2WI‐ADC images. The texture parameters from T2WI, ADC1000, and ADC2000 were acquired.
Statistical Tests
The texture parameters were compared between the two types by using unpaired Student's t‐test. Receiver operating characteristic (ROC) curves and logistic regression analyses were used to assess their diagnostic performance.
Results
Significant differences in TA parameters of ADC1000 and ADC2000 were observed between soft and hard types (P < 0.05 for all), whereas the TA of T2WI resulted in no significant difference (P > 0.05 for all). TA of ADC2000 provided a superior diagnostic performance compared with that of ADC1000 (P = 0.038). A combination of mean value and entropy of ADC2000 yielded an AUC, a sensitivity, and a specificity of 0.911, 78.4% and 92.3%, respectively.
Data Conclusion
TA of ADC values were useful for assessing the tumor consistency of pituitary macroadenomas. ADC2000 may facilitate better type discrimination.
Level of Evidence: 3
Technical Efficacy Stage: 2
J. Magn. Reson. Imaging 2020;51:1507–1513.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Understanding the impact of rock bareness on the transpiration in karst plants is essential to karst rocky desertification control and sustainable management of plantation in karst area. This study ...focused on the variations in sap flow of
Zenia insignis
caused by different rock bareness rate, and the impact of climate factors, soil water content
(SWC)
and leaf area index
(LAI)
on transpiration in karst plants, by continuously measuring sap flux densities
(Fd)
of 12 sample trees using thermal dissipation probes and monitoring micrometeorology and
SWC
on a typical karst hill in north Guangdong of China during the year of 2016. Results show that: (1) the maximum hourly sap flux density occurred at 11:00–14:00 and the peak daily sap flux density occurred in September. (2) Sap flow density of
Zenia insignis
increased with rock bareness rate at all hourly, daily and monthly scales, with the sequence of extremely severe > severe > moderate > mild rock bareness. (3) The transpiration of
Zenia insignis
is controlled by different factors at different temporal scales. At hourly scale, transpiration was highly (n=144,
R
2
>0.72) correlated to Solar radiation
(R
s
), Air temperature
(T
a
), relative humidity
(RH)
, and water vapor pressure deficit
(VPD).
At daily scale, transpiration was greatly (77=366,
R
2
>0.31) affected by Solar radiation
(Rs)
, Air temperature
(T
a
), and water vapor pressure deficit
(VPD).
While at monthly scale, transpiration was mainly (n=12,
R
2
=0.8s) controlled by
LAI.
Our study proved that
Zenia insignis
has a good physiecological adaption to fragile karst environment, and
Zenia insignis
plantation has long-term sustainability even in extremely rocky landscapes. The results may provide scientific basis for plantation management and ecological restoration in karst area.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In the present study, we investigated the role of endogenous neurotrophin-3 in nerve terminal sprouting 2 months after spinal cord dorsal root rhizotomy. The left L1-5 and L7-S2 dorsal root ganglia ...in adult cats were exposed and removed, preserving the L6 dorsal root ganglia. Neurotrophin-3 was mainly expressed in large neurons in the dorsal root ganglia and in some neurons in spinal lamina II. Two months after rhizotomy, the number of neurotrophin-3-positive neurons in the spared dorsal root ganglia and the density of neurite sprouts emerging from these ganglia were increased. Intraperitoneal injection of an antibody against neurotrophin-3 decreased the density of neurite sprouts. These findings suggest that endogenous neurotrophin-3 is involved in spinal cord plasticity and regeneration, and that it promotes axonal sprouting from the dorsal root ganglia after spinal cord dorsal root rhizotomy.
Human herpesvirus 6 (HHV-6) is a T-lymphtropic and neurotropic virus that can infect various types of cells. Sequential studies reported that apoptosis of glia and neurons induced by HHV-6 might act ...a potential trigger for some central nervous system (CNS) diseases. HHV-6 is involved in the pathogenesis of encephalitis, multiple sclerosis (MS) and fatigue syndrome. However, the mechanisms responsible for the apoptosis of infected CNS cells induced by HHV-6 are poorly understood. In this study, we investigated the cell death processes of primary human fetal astrocytes (PHFAs) during productive HHV-6A infection and the underlying mechanisms.
HHV-6A can cause productive infection in primary human fetal astrocytes. Annexin V-PI staining and electron microscopic analysis indicated that HHV-6A was an inducer of apoptosis. The cell death was associated with activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP), which is known to be an important substrate for activated caspase-3. Caspase-8 and -9 were also significantly activated in HHV-6A-infected cells. Moreover, HHV-6A infection led to Bax up-regulation and Bcl-2 down-regulation. HHV-6A infection increased the release of Smac/Diablo, AIF and cytochrome c from mitochondria to cytosol, which induced apoptosis via the caspase-dependent and -independent pathways. In addition, we also found that anti-apoptotic factors such as IAPs and NF-κB decreased in HHV-6A infected PHFAs.
This is the first demonstration of caspase-dependent and -independent apoptosis in HHV-6A-infected glial cells. These findings would be helpful in understanding the mechanisms of CNS diseases caused by HHV-6.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A field study was conducted to determine the effect of a combination of ridge and furrow method of in-situ rainwater harvesting with gravel mulch on corn production, soil moisture storage, and ...water-use efficiency in the dry semi-arid region of China. Results showed that plastic-covered ridges had an average runoff efficiency (runoff/rainfall) of 87% as compared to 7% for bare ridges, and could generate runoff at a threshold value of 0·8±0·2 mm rainfall. Bare ridges produced runoff only under high intensity rainfall events, and was ineffective for harvesting rainfall in the study area. The plastic-covered ridge and gravel-mulched furrow method of rainwater harvesting was effective in conserving moisture and increasing yield and water-use efficiency. The grain yield in this treatment was 1·9 times that of the conventional flat soil cultivation (control), and the water-use efficiency was 1·8 times that of the control. The good performance of the film-covered surface ridges and gravel-mulched furrows is attributed to the better utilization of light rains, improvement of infiltration in the root zone, and suppression of evaporation losses.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Background Cytosine deaminase （CD） converts 5-fluorocytosine （5-FC） to 5-fluorouracil （5-FU） in CD/5-FC gene therapy, 5-FU will be mostly converted into nontoxic 13-alanine without uracil ...phosphoribosyltransferase （UPRT）. UPRT catalyzes the conversion of 5-FU to 5-fluorouridine monophosphate, which directly kills CD：：UPRT-expressing cells and surrounding cells via the bystander effect. But the pharmacokinetics and the bystander effect of CD：：UPRT/5-FC has not been verified in vivo and in vitro. Before the CD：：UPRT/5-FC bi-gene therapy system is used in clinical trial, it is essential to monitor the transgene expression and function in vivo. Thus, we developed a preclinical tumor model to investigate the feasibility of using ^19F-magnetic resonance spectroscopy （^19F-MRS） and optical imaging to measure non-invasive CD and UPRT expression and its bystander effect. Methods C6 and C6-CD：：UPRT cells were cultured with 5-FC. The medium, cells and their mixture were analyzed by ^19F-MRS. Rats with intracranial xenografted encephalic C6-CD：：UPRT glioma were injected intraperitoneally with 5-FC and their ^19F-MRS spectra recorded. Then the pharmacokinetics of 5-FC was proved. Mixtures of C6 and C6-CD：：UPRT cells at different ratios were cultured with 5-FC and the cytotoxic efficacy and survival rate of cells recorded. To determine the mechanism of the bystander effect, the culture media from cell comprising 25% and 75% C6-CD：：UPRT cells were examined by ^19F-MRS. A comparative study of mean was performed using analysis of variance （ANOVA）. Results ^19F-MRS on samples from C6-CD：：UPRT cells cultured with 5-FC showed three broad resonance signals corresponding to 5-FC, 5-FU and fluorinated nucleotides （F-Nuctd）. For the C6 mixture, only the 5-FC peak was detected. In vivo serial ^19F-MRS spectra showed a strong 5-FC peak and a weak 5-FU peak at 20 minutes after 5-FC injection. The 5-FU concentration reached a maximum at about 50 minutes. The F-Nuctd signal appeared after about 1 hour, reached a maximum at around 160 minutes, and was detectable for several hours. At a 10% ratio of C6-CD：：UPRT cells, the survival rate was （79.55±0.88）% （P 〈0.01）. As the C6-CD：：UPRT ratio increased, the survival rate of the cells decreased. ^19F-MRS showed that the signals for 5-FU and F-Nuctd in the culture medium increased as the ratio of C6-CD：：UPRT in the mixture increased. Conclusions ^19F-MRS studies indicated that C6-CD：：UPRT cells could effectively express CD and UPRT enzymes. The CD：：UPRT/5-FC system showed an obvious bystander effect. This study demonstrated that CD：：UPRT/5-FC gene therapy is suitable for 5-FC to F-Nuctd metabolism; and ^19F-MRS can monitor transferred CD：：UPRT gene expression and catalysis of substrates noninvasively, dynamically and quantitatively.
► The white thrombus of 1.7mm in diameter is found to be optimal for producing segmental occlusions in the proximal MCA trunk through ipsilateral ICA injection. ► We generate an ischemic model which ...can recapitulate the radiologic and histologic changes in lacunar infarcts in beagle dogs. ► We are the first group to study the time course of lacunar infarction in acute phase using diffusion weighted imaging in beagle dogs.
It is estimated that lacunar infarcts account for 25% of all ischemic strokes, but its exact etiology is still on debating. The existing controversies include whether the embolisms can indeed cause lacunar stroke in humans or animal models. We hypothesized that lacunar infarction can be induced by the proximal middle cerebral artery (MCA) segmental occlusion involving the orifices of lenticulostriate arteries in animal models, which have abundant distal cerebral collateral anastomosis. Our work here establishes a proximal MCA occlusion model using thrombi (autologous blood clots about 1.7mm in diameter and 5mm in length) in 8 beagle dogs, evaluates the progression of ischemic lesions at 30min interval within 6h after embolization using the diffusion weighted imaging (DWI), and discusses the potential mechanisms of lacunar infarction. Our results indicate that the left proximal MCAs can be successfully occluded in all dogs using interventional single-thrombus method. The small solitary or multiple ischemic lesions shown in DWI were observed in the deep brain area, with the mean detecting time of 1.21±0.45h using DWI and diameter of 6.62±0.60mm in 6h-DWI after procedure. In conclusion, our method established an ischemic model which can recapitulate the radiologic and histologic changes in lacunar infarcts, suggesting that emboli can cause lacunar infarcts in animal model.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
To examine the effects of anisomycin on glioma cells and the related mechanisms in vitro.
The U251 and U87 human glioblastoma cell lines were tested. The growth of the cells was analyzed using a ...CCK-8 cell viability assay. Apoptosis was detected using a flow cytometry assay. The expression of proteins and phosphorylated kinases was detected using Western blotting.
Treatment of U251 and U87 cells with anisomycin (0.01-8 μmol/L) inhibited the cell growth in time- and concentration-dependent manners (the IC(50) values at 48 h were 0.233±0.021 and 0.192±0.018 μmol/L, respectively). Anisomycin (4 μmol/L) caused 21.5%±2.2% and 25.3%±3.1% of apoptosis proportion, respectively, in U251 and U87 cells. In the two cell lines, anisomycin (4 μmol/L) activated p38 MAPK and JNK, and inactivated ERK1/2. However, neither the p38 MAPK inhibitor SB203580 (10 μmol/L) nor the JNK inhibitor SP600125 (10 μmol/L) prevented anisomycin-induced cell death. On the other hand, anisomycin (4 μmol/L) reduced the level of PP2A/C subunit (catalytic subunit) in a time-dependent manner in the two cell lines. Treatment of the two cell lines with the PP2A inhibitor okadaic acid (100 nmol/L) caused marked cell death.
Anisomycin induces glioma cell death via down-regulation of PP2A catalytic subunit. The regulation of PP2A/C exression by anisomycin provides a clue to further study on its role in glioma therapy.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Cattle dung, firewood, and crop straw have being used as survival necessities by farmers and herdsmen for thousands of years in Tibet. Until recently such biotic energy source still constitutes more ...than 92 per cent of total rural energy consumption due to lack of petroleum, coal and new alternative energy sources. As a result, environmental degradation such as land desertification, soil erosion, grassland degradation and soil fertility reduction is increasingly aggravated, the area of desertified land has increased 1467.5 km2 from 1991 to 1997. Degraded area of grassland has reached 2.60 x 10(7) hm2, increased by 116.1% from 1987 to 1996. To prevent further deterioration of eco-environment in Tibet great efforts should be made to make full use of ample solar energy, wind energy and other biotic energy of the Qinghai-Tibet Plateau. The solar cooking stoves and solar hothouse, expand forest area and replace existing abiotic energy sources with firewood forest should be popularized. This is an urgent task to protect the eco-environment of Tibet today.
We investigated the root distribution and yield of watermelon grown with a gravel–sand mulch, a plastic-film mulch, or a combination of the two mulches, and in a non-mulched control under natural ...precipitation and under three levels of drip irrigation (23, 45, and 68
mm). Roots reached depths of 1.5
m in mulched fields, but most roots (more than 85.3% in 2001 and 92.5% in 2002) in the non-irrigated control were found within the top 100
cm of soil. The gravel–sand mulch increased watermelon root length density (RLD) by 75% compared with the control. In the mulched field, RLD was higher in the top 30
cm of soil in the control (non-irrigated) treatment in 2002 than in 2001, a relatively dry year. Root growth was densest at 68
mm of irrigation in 2001 and without irrigation in 2002. RLD reached a maximum of 1.95
cm
cm
−3 when irrigation and rainfall totalled 194
mm, but decreased at higher levels. The relationship between RLD and total irrigation plus rainfall followed a quadratic curve. In fields mulched with the gravel–sand mixture, roots grew more in the absence of the plastic-film mulch, except in the 68-mm irrigation treatment in 2002, but there was little difference among treatments in 2001. In the mulched field, watermelon yields decreased significantly with decreasing irrigation in 2001, but the yields did not differ significantly from those in 2002. Watermelon extracted more water from soil in 2001 than in 2002. These results demonstrated that rainfall and irrigation affect both the horizontal and vertical distribution of roots and yield. Moderate water deficits increased root length.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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