632 research outputs found
The Application of Diffusion- and Perfusion-Weighted Magnetic Resonance Imaging in the Diagnosis and Therapy of Acute Cerebral Infarction
Diffusion- and perfusion-weighted magnetic resonance imaging (DWI and PWI) was applied for stroke
diagnose in 120 acute (< 48 h) ischemic stroke patients. At hyperacute (< 6 h) stage, it is
difficult to find out the infarction zone in conventional T1 or T2 image, but it is easy in DWI,
apparent diffusion coefficient (ADC) map; when at 3–6-hour stage it is also easy in PWI,
cerebral blood flow (CBF) map, cerebral blood volume (CBV) map, and mean transit time (MTT) map;
at acute (6–48 h) stage, DWI or PWI is more sensitive than conventional T1 or T2 image too.
Combining DWI with ADC, acute and chronic infarction can be distinguished. Besides,
penumbra which should be developed in meaning was used as an indication or to evaluate the
therapeutic efficacy. There were two cases (< 1.5 h) that broke the model of penumbra because abnormity was found in DWI but not that in PWI, finally they recovered without any sequela
(4-Hydroxyphenyl)methanaminium 2-(4-sulfanylphenyl)acetate
In the title molecular salt, C7H10NO+·C8H7O2S−, the crystal structure is stabilized by intermolecular N—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds
A new species of Fordiophyton (Sonerileae, Melastomataceae) from Yunnan, China
Fordiophyton jinpingense (Melastomataceae; Sonerileae), a species occurring in south-eastern Yunnan, China, is described as new, based on morphological and molecular data. Phylogenetic analyses, based on nrITS sequence data, showed that, except F. breviscapum, all species sampled in Fordiophyton formed a strongly supported clade in which two geographical lineages were recovered. The generic placement of F. jinpingense is well supported by phylogenetic analyses and a character combination of 4-merous flowers, distinctly dimorphic stamens and the connectives basally not calcarate. Molecular divergence and morphological evidence indicate that F. jinpingense is well separated from other members of the genus, thus justifying its recognition as a distinct species. Fordiophyton jinpingense is phylogenetically closest to F. repens, but differs markedly from the latter in stem morphology (short, obtusely 4-sided vs. long, 4-angular), habit (erect vs. creeping), leaf size (6–16.5 × 4.5–13 cm vs. 4–7.5 × 4–6.5 cm) and flower number per inflorescence (5–13 vs. 3–6)
The genetic contribution of CIDEA polymorphisms, haplotypes and loci interaction to obesity in a Han Chinese population
To investigate the association of tag-SNPs and haplotype structures of the CIDEA gene with obesity in a Han Chinese population. Five single nucleotide polymorphisms (SNPs) (rs1154588/V115F, rs4796955/SNP1, rs8092502/SNP2, rs12962340/SNP3 and rs7230480/SNP4) in the CIDEA gene were genotyped in a case-control study. Genotyping was performed using the sequenom matrixassisted laser desorption/ionization time-of-flight mass spectrometry iPLEX platform. There were significant differences between the obese and control groups in genotype distributions of V115F (P\u3e0.001), SNP1 (P = 0.006) and SNP2 (P = 0.005). Carriers of V115F-TT, SNP1-GG and SNP2-CC genotypes had a 2.84-fold (95 % CI 1.73-4.66), 2.19-fold (95 % CI 1.09-4.38) and 4.37-fold (95 % CI 1.21-15.08) increased risk for obesity, respectively. Haplotype analysis showed that GTTC (SNP1/ SNP2/V115F/SNP4) had 1.41-fold (95 % CI 1.02-1.95) increased risk for obesity; whereas, haplotype TTGC had 0.48-fold (95 % CI 0.24-0.96) decreased risk for obesity. Using the multifactor dimensionality reduction method, the best model including SNP1, SNP2, V115F and SNP4 polymorphisms was identified with a maximum testing accuracy to 59.32 % and a perfect cross-validation consistency of 10/10 (P = 0.011). Logistic analysis indicated that there was a significant interaction between SNP1 and V115F associated with obesity. Subjects having both genotypes of SNP1/GG and V115F/TT were more susceptible to obesity in the Han Chinese population (OR 2.66, 95 %: 1.22-5.80). Genotypes of V115F/TT, SNP1/ GG and SNP2/CC and haplotype GTTC of CIDEA gene were identified as risk factors for obesity in the Han Chinese population. The interaction between SNP1 and V115F could play a joint role in the development of obesity
Two-tiered mutualism improves survival and competitiveness of cross-feeding soil bacteria.
Metabolic cross-feeding is a pervasive microbial interaction type that affects community stability and functioning and directs carbon and energy flows. The mechanisms that underlie these interactions and their association with metal/metalloid biogeochemistry, however, remain poorly understood. Here, we identified two soil bacteria, Bacillus sp. BP-3 and Delftia sp. DT-2, that engage in a two-tiered mutualism. Strain BP-3 has low utilization ability of pyruvic acid while strain DT-2 lacks hexokinase, lacks a phosphotransferase system, and is defective in glucose utilization. When strain BP-3 is grown in isolation with glucose, it releases pyruvic acid to the environment resulting in acidification and eventual self-killing. However, when strain BP-3 is grown together with strain DT-2, strain DT-2 utilizes the released pyruvic acid to meet its energy requirements, consequently rescuing strain BP-3 from pyruvic acid-induced growth inhibition. The two bacteria further enhance their collective competitiveness against other microbes by using arsenic as a weapon. Strain DT-2 reduces relatively non-toxic methylarsenate [MAs(V)] to highly toxic methylarsenite [MAs(III)], which kills or suppresses competitors, while strain BP-3 detoxifies MAs(III) by methylation to non-toxic dimethylarsenate [DMAs(V)]. These two arsenic transformations are enhanced when strains DT-2 and BP-3 are grown together. The two strains, along with their close relatives, widely co-occur in soils and their abundances increase with the soil arsenic concentration. Our results reveal that these bacterial types employ a two-tiered mutualism to ensure their collective metabolic activity and maintain their ecological competitive against other soil microbes. These findings shed light on the intricateness of bacterial interactions and their roles in ecosystem functioning
Risk factors of distant brain failure for patients with newly diagnosed brain metastases treated with stereotactic radiotherapy alone
<p>Abstract</p> <p>Objective</p> <p>To explore the risk factors of distant brain failure (DBF) for patients with brain metastasis (BM) who were treated with stereotactic radiotherapy alone and to group the patients on the basis of their risk levels.</p> <p>Methods and Materials</p> <p>We retrospectively analyzed 132 newly diagnosed BM patients who were treated with stereotactic radiotherapy alone from May 2000 to April 2010. Kaplan-Meier and Cox proportional hazards regression analyses were performed for univariate and multivariate analyses.</p> <p>Results</p> <p>The 1-year incidence rate of DBF was 44.7%, and the median DBF time (MDBFT) was 18 months. In multivariate analysis, the risk factors of DBF were the number of BMs greater than 1 (p = 0.041), uncontrolled extracranial disease (p = 0.005), interval time (IT) of less than 60 months between the diagnosis of primary tumor and BM (p = 0.024), and total volume of BM was greater than 6 cc (p = 0.049). Each risk factor was assigned 1 score. The median survival times for the patients with scores of 0-1, 2-3, and 4 were 31, 12, and 10 months, respectively, and the corresponding MDBFTs were not reached, 13, and 3 months, respectively, (p < 0.001). The crude DBF incidence rates in patients with scores of 0-1, 2-3, and 4 were 14.8%, 50.0%, and 76.9%, respectively, (p < 0.001).</p> <p>Conclusions</p> <p>The patients with scores of 0-1 had a lower risk of DBF than the patients with higher scores did, and it may be reasonable to treat these patients with SRS alone and resort to whole-brain radiation therapy only for salvage. The patients with a score of 4 had the highest risk of developing DBF after stereotactic radiotherapy alone, these patients may be candidates for initial whole-brain radiation therapy or clinical trials. The patients with a score of 2-3 had a moderate risk of developing DBF, SRT alone combined with close clinical monitoring would be the optimal treatment regimen for such patients, and for those patients with difficulties in receiving close clinical mornitoring, SRT combined with WBRT will be more suitable.</p
Sequence-dependent abnormal aggregation of human Tau fragment in an inducible cell model
AbstractA pathological hallmark of Alzheimer disease (AD) is the accumulation of misfolded hyperphosphorylated microtubule-associated protein Tau within neurons, forming neurofibrillary tangles and leading to synaptic dysfunction and neuronal death. Here we study sequence-dependent abnormal aggregation of human fragment Tau244–372 in an inducible cell model. As evidenced by confocal laser scanning microscopy, Western blot, and immunogold electron microscopy, fibril-forming motifs are essential and sufficient for abnormal aggregation of Tau244–372 in SH-SY5Y neuroblastoma cells induced by Congo red: when its two fibril-forming segments PHF6 and PHF6* are deleted, Tau244–372 does lose its ability to form fibrils in SH-SY5Y cells, and the replacement of PHF6 and PHF6* with an unrelated amyloidogenic sequence IFQINS from human lysozyme does rescue the fibril-forming ability of Tau244–372 in SH-SY5Y cells. By contrast, insertion of a non-fibril forming peptide GGGGGG does not drive the disabled Tau244–372 to misfold in SH-SY5Y cells. Furthermore, as revealed by quantum dots based probes combined with annexin V staining, annexin V-FITC apoptosis detection assay, and immunofluorescence, fibril-forming motifs are essential and sufficient for early apoptosis of living SH-SY5Y cells induced by abnormal aggregation of Tau244–372. Our results suggest that fibril-forming motifs could be the determinants of Tau protein tending to misfold in living cells, thereby inducing neuronal apoptosis and causing the initiation and development of AD
- …