Autoionization path of double Rydberg states in calcium.
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Journal Article↗
Biomedical subjects
M Xue
Publications and source records attributed to M Xue.
Postictal alteration of sodium content and apparent diffusion coefficient in epileptic rat brain induced by kainic acid.
PURPOSE: We studied temporal changes of brain sodium and apparent diffusion coefficient (ADC) in a temporal lobe epilepsy (TLE) rat model using kainic acid (KA). METHODS: In situ three-dimensional 23Na magnetic resonance imaging (MRI) and proton diffusion-weighted imaging (DWI) were used. KA at a dose of 10 mg/kg body weight and 12 adult Sprague Dawley rats weighing 228-318 g (268 +/- 25 g) were used. RESULTS: Twenty-four hours after KA injection, magnetic resonance (MR) visible sodium levels increased in both the pyriform cortex (+90%) and amygdala (+68%) and increased insignificantly in the hippocampus (+18%) and caudate-putamen (12%). The ADC in the pyriform cortex showed a -9% decrease at 5 h postictally, reaching -30% at 24 h, whereas in the amygdala decreases were -8 and -26% respectively. A significant decrease in ADC (-7%) in the hippocampus was also observed 24 h postically. Seven days later, sodium increases persisted, whereas ADC returned to normal level. CONCLUSIONS: The increase in MR visible sodium, associated with the decrease in ADC is consistent with the hypothesis that sequential seizures caused an increase in sodium influx and perturbation of membrane ion homeostasis, which eventually evolved into an irreversible phase of cellular edema, with increased MR visible intracellular sodium and decreased ADC. Return of ADC to near-control level and persistent high sodium level at 7 days may be explained by the increase in extracellular space and tissue necrosis.
Amygdala↗
Phosphorylation and nuclear localization of the varicella-zoster virus gene 63 protein.
The protein encoded by varicella-zoster virus open reading frame 63 and carboxy-terminal deletions of the same were expressed either as fusion proteins at the carboxy terminus of the maltose-binding protein in Escherichia coli or independently in transfected mammalian cells. The truncations contained amino acids 1 to 142 (63 delta N) or 1 to 210 (63 delta K) of the complete 278-amino-acid primary sequence. Recombinant casein kinase II phosphorylated the 63F and 63 delta KF fusion proteins in vitro but did not phosphorylate the 63 delta NF fusion protein, implying that phosphorylation occurred between amino acids 142 and 210. Immunoprecipitation of 35S- or 32P-labelled extracts of cells transfected with plasmids expressing 63, 63 delta N, or 63 delta K also indicated that in situ phosphorylation most likely occurred between amino acids 142 and 210. These combined results suggest that casein kinase II plays a significant role in the phosphorylation of the varicella-zoster virus 63 protein. Indirect immunofluorescence of transfected cells indicated nuclear localization of the 63 protein and cytoplasmic localization of 63 delta K and 63 delta N, implying a requirement for sequences between amino acids 210 and 278 for efficient nuclear localization.
Amino Acid Sequence↗
Progress in studies on the overwintering of the mosquito Culex tritaeniorhynchus.
A detailed review is presented of half a century's research in Japan, Korea and the temperate zone of China on the overwintering of Culex tritaeniorhynchus, the main vector of Japanese encephalitis. The evidence indicates that in the temperate zone, two types of overwintering strategy can be distinguished in Cx. tritaeniorhynchus, ie survival by adults in situ in a dormant state, or migration by individuals which are in reproductive diapause. The authors contend that the former strategy is not very effective, and individuals which overwinter in this way do not constitute the main source of the next season's mosquito populations. On the contrary, new mosquito populations seem to be established by groups of adults which appear suddenly, early in the year, and which are probably windborne migrants from the south. It is concluded that further research into the mode of overwintering of Cx. tritaeniorhynchus should focus on the effective source of the populations which appear in temperate areas in early spring, and that efforts should be made to increase our understanding of the migration patterns of this species.
Animals↗
Sensitivity of magnetic resonance diffusion-weighted imaging and regional relationship between the apparent diffusion coefficient and cerebral blood flow in rat focal cerebral ischemia.
BACKGROUND AND PURPOSE: Magnetic resonance (MR) diffusion-weighted imaging (DWI), a noninvasive procedure, may play an important role in detecting and accurately localizing the extent of evolving infarction within the period immediately following stroke. We evaluated the sensitivity and specificity of DWI in detecting ischemia and compared a quantitative measure derived from the DWI, the apparent diffusion coefficient (ADC), with autoradiographic cerebral blood flow (CBF) in an experimental model of focal cerebral ischemia in rats. METHODS: MR imaging data were obtained with a General Electric 4.7-T horizontal bore magnet CSI II system with self-shielded gradients. DWI was acquired within 41 +/- 6 minutes (mean +/- SD) after onset of ischemia and repeated at 169 +/- 14 minutes, followed by CBF determination at 237 +/- 21 minutes. DWI, ADC, and CBF images from each animal were then compared. RESULTS: The sensitivities for detecting an abnormality at 1 and 3 hours for DWI were significantly different, and the sensitivity of 3-hour DWI did not differ from the CBF sensitivity of 99%. A mean +/- SD ADC threshold of 460 +/- 95 microns 2/s was defined as 45% higher than the low ADC in the ischemic core compared with the contralateral ADC. Subthreshold ADC area and ischemic area were significantly correlated (r2 = .69, P < .05). In 19 of 48 regions of interest classified as ischemic (< 35 mL.100 g-1.min-1) from both the 3-hour ADC and CBF images, 3-hour ADC correlated significantly with CBF (r2 = .27, n = 19, P < .05), whereas in the nonischemic regions ADC was inversely correlated with CBF. Several ischemic regions showed a sharp drop in ADC to 37% (P < .001, n = 5) compared with all other regions (n = 43) from 1 to 3 hours. CONCLUSIONS: Because of the change in the sensitivity of detecting ischemia with DWI, the difference in correlation of CBF with ADC between ischemic and nonischemic cortex, and the presence of several regions in which ADC dropped to 37% from 1 to 3 hours, our data suggest that ADC values potentially can be used to monitor evolving infarction.
Animals↗
[Effect of Tripterygium wolfordii on inhibition of rejection reaction of allogeneic skin graft in mice].
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Animals↗
Magnetic resonance diffusion-weighted imaging: sensitivity and apparent diffusion constant in stroke.
Magnetic resonance diffusion-weighted imaging (MR-DWI) is sensitive to the diffusibility of water and may offer characterization and anatomical localization of stroke leading to early tailored therapeutic intervention. We compared DWI, the apparent diffusion constant (ADC), and autoradiographic cerebral blood flow (CBF) in a model of focal cerebral ischemia in the rat. Sprague-Dawley rats were embolized with a single silicone cylinder injected into the internal carotid artery. Both common carotids were permanently ligated. The animals were anesthetized (isoflurane in O2), and paralyzed (gallamine). MR-DWI were obtained with a GE 4.7 T magnet (TE = 3 s, TR = 80 msec, b = 2393.10(-3) mm2/s, slice thickness 3 mm). DWI and CBF autoradiograms were compared visually. ADC was assessed in various regions, including ischemic cortex and a region homologous to ischemic cortex. Imaging times from stroke onset were 50 +/- 6 min (mean +/- SEM) for DWI, 185 +/- 17 min for a second DWI. CBF was determined at 258 +/- 15 min. The specificity was 100% at both 50 min and 185 min, indicating that there were no false positives; in 3 animals ischemia was not present. However, the sensitivity analysis indicated that early DWI yields some false negatives; at 50 min the sensitivity was 60%. We attribute our result of low early sensitivity to small infarcts in relation to the slice thickness. Later, at 185 min, sensitivity was 100%. The first ADCs were higher than the second ADC values in ischemic cortex. For infarcts larger than the slice thickness, early MR-DWI is highly sensitive for imaging evolving ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Observation of strong electronic correlation for highly excited double Rydberg states of ytterbium.
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Journal Article↗
Temporal lobe epilepsy: presurgical localization with proton chemical shift imaging.
PURPOSE: To assess two-dimensional phase-encoded proton chemical shift imaging for potential clinical application in presurgical localization of temporal lobe epilepsy (TLE). MATERIALS AND METHODS: Interictal chemical shift imaging studies were performed in 25 patients (17 unilateral, eight bilateral epileptogenic abnormalities) and 12 healthy volunteers. Results were compared with those of electroencephalography. For each temporal lobe, the volume of interest (VOI) included mesial, lateral, anterior, and posterior areas. RESULTS: The epileptogenic zone was characterized by an abnormal pattern of decreased signal intensity in the N-acetylaspartate (NAA) peak, either increased or unchanged choline (Cho) level relative to creatine (Cr) signal intensity, and, occasionally, elevated lactate level. NAA/Cho was the most sensitive and reliable quantitative marker for abnormality. The sensitivity and specificity of this technique compared with EEG were 90% and 85%, respectively. The difference in NAA/Cho between epileptogenic and normal temporal lobes was highly significant (P < .001). No statistically significant difference was found between normal temporal lobes and patients' uninvolved temporal lobes. CONCLUSION: NAA/Cho is an excellent marker for localizing the epileptogenic zone in TLE.
Adolescent↗
[Measuring of immune complexes and antinuclear antibodies in effusion of secretory otitis media].
Immune complexes (IC) and antinuclear antibodies (ANA) in middle ear effusions from 40 cases (45 ears) of secretory otitis media were measured using PEG precipitation method and fluorescent microscopy. The range of absorbence for IC varies between 0.124-0.512 in patients and is higher than those (0.132) in normal human sera. Thirty-two ears (71.1%) are ANA positive. The result indicates that secretory otitis media is related with autoimmunity. The deposit of IC may be one of the causes of effusion in otitis media.
Adolescent↗
Effects of Sr-hydroxyapatite microcrystal on cultured cell.
Strontium-hydroxyapatite microcrystals (Sr-HAp sol) were produced by a wet method at room temperature with ultrasonic irradiation and were applied to MC3T3-E1, ROS, and L cells for periods of 2, 4, and 6 days in vitro. The effect on cell growth, the variation of LDH and Ca contents in the media, and attachment between cell and microcrystal were investigated. Sintered Sr-HAp and HAp sol were used as controls. A slight inhibitory effect of Sr-HAp sol on cell growth was found. The degree of inhibition was nearly the same as HAp sol. However, it was stronger than sintered Sr-HAp. The contents of LDH in the media increased with the degree of cell inhibition, and the contents of Ca in the media decreased from the initial stage of cell-sol contact. A good attachment of Sr-HAp sol to cultured cells was seen by phase-contrast microscopy and SEM.
Animals↗
Short echo time proton spectroscopy of human brain using a gradient head coil.
Short echo time, single voxel localized proton spectroscopy was accomplished using a stimulated echo (STEAM) sequence running on a Siemens 1.5-T system with a head coil incorporating the Z and Y gradients. Spectra from the temporal lobe, the cerebellum and mid brain were acquired from a group of normal volunteers using the following parameters: voxel size = 8 ml, TE = 22 msec, 512 signal averages and TR = 1.7 sec. STEAM spectra acquired with the small diameter gradients showed significantly fewer artifacts at short TE, allowing the observation of glutamate/glutamine, GABA, taurine, and inositol in addition to the prominent resonance of choline, creatine/phosphocreatine and N-acetylaspartate (NAA). The levels of chlorine, creatine and NAA were found to be significantly different in the three regions of the brain examined.
Adult↗
[Electron microscopic observation on the effect of electroacupuncture (EA) on the ultrastructure of nucleus raphe dorsalis (NRD) in rats].
Nucleus raphe dorsalis (NRD) plays an important role in acupuncture analgesia. The aim of this investigation is to determine the effects of electroacupuncture (EA) analgesia on the ultrastructure of NRD. 12 Wistar rats (220-250g) were divided into control and experiment groups. Pain threshold was determined by potassium iontophoretic colorimetry. EA was applied at bilateral "Zusanli" points. The effective analgesia animals and control animals were sacrificed and the NRD were taken out for electron microscopic observation. In EA analgesia groups, NRD was observed the number of the clear round vesicle-containing terminals and clear round vesicles with the granular vesicle-containing terminals showed a significant decrease and sometimes vesicles were emptied. The area of presynaptic terminals were expanded. Some synaptic gaps appeared narrow profiles. Part of the mitochondria and endoplasmic reticulum in neuron and neurogliocytes appeared the expanded profiles. These ultrastructural change of the NRD in EA analgesia might indicate the neurons and neurogliocytes were in active functional state.
Acupuncture Analgesia↗
Magnetic resonance imaging of cutaneous neoplasms: clinicopathologic correlation.
Recently, magnetic resonance imaging (MRI) has been reported to be clinically useful, in selected cases, in patients with melanocytic skin lesions. This report describes good resolution, clinically useful MRI scans of squamous cell carcinoma, dermatofibroma, and primary cutaneous B-cell lymphoma. The tumor depth measured by MRI was in excellent correlation with Breslow's depth measurements, indicating that MRI is probably the radiologic technique of choice for preoperative evaluation of the extent and depth of primary and recurrent skin tumors. This report also provides the authors' recommendations for obtaining optimal MRI images of cutaneous lesions.
Adult↗
[Pharmacokinetics and metabolism of artesunate in cows].
The pharmacokinetics of artesunate (AS) was studied in 3 cows, single dose of AS (5 mg/kg) were administered intravenously and the drug concentrations were determined by means of a TLC method developed in our laboratory. The plasma drug concentration-time course of AS, after the treatment with a pharmacokinetic microcomputer program MCPKP edited by Wen-Jiang Xia, was found to be best fitted to a two compartment open model and its pharmacokinetic parameters were as follows, T1/2 alpha = 2.43 min, T1/2 beta = 31.45 min, V1 = 0.124 L/kg, VB = 0.937 L/kg, ClB = 0.0215 L/kg. min, AUC = 236 mg/L.min. Dihydroartemisinine (DHA), the main active metabolite of AS in the bodies, was detected simultaneously. Peak plasma concentration of 3.5 micrograms/ml of DHA was reached at about 3 minutes after dosing and the AUC was 82 mg/L.min.
Animals↗
Spectral editing of tumor 13C MRS in situ.
The editing pulse sequence DEPT (D.T. Pegg, D.M. Doddrell, and M.R. Bendall, J. Chem. Phys. 77, 2745 (1982)) was modified using a scheme of various composite pulses and a 16-step phase cycling to obtain proton-decoupled natural-abundance 13C edited subspectra of solid tumors. A solenoidal probe including a Faraday shield and an orthogonal saddle decoupling coil was built for this purpose.
Animals↗
[In vivo radiotelemetric study of strain on the rabbit mandible].
Using strain transducer to measure bone strain and stress in vitro on-line techniques are more popular. In this article, the radiotelemetric method is selected for measuring living tissue mechanic properties. The angle of rabbit mandible serves as tested site. The transducer is minutely foil type electrical resistance strain gage. The measuring instruments are KYOWA telemeter for strain measurement MRT-200 series. When the mandible is in rest position, the tested site shows no change of strain; when the mandible acts without eating any food, small change of strain appear; when the rabbit mastication two kinds of food, the tested site shows the regular change of tension strain and compressive strain, the former is about 150 microstrain and latter is about 30 microstrain. The rates of strain are different when the animal mastication the different foods. Comparing with the on-line technique method, the radiotelemetric method has significant advantages, and is the better test way for studying mechanic properties of living tissue.
Animals↗
Monitoring therapeutic response of human superficial tumors using phase-encoded spectroscopy.
A one-dimensional phase-encoded spectroscopy sequence was implemented on a GE 1.5-T Signa imager and the feasibility of its application to monitor the 31P metabolites of superficial tumors was demonstrated. Serial 31P spectra of 1-cm slices with adequate signal-to-noise ratio and insignificant T2 weighting can be obtained in 28 min. The degree of "bleeding" effect was reduced with increased phase-encoding steps.
Adult↗