1/T1 NMRD profiles of solutions of Mn2+ and Gd3+ protein-chelate conjugates

Bovine immunoglobulins (IgG) and bovine serum albumin (BSA) were multiply labeled with multidentate ligands, either ethylenediaminetetraacetic acid (EDTA) or diethylenetriaminepentaacetic acid (DTPA), and metal ions were inserted to form the ternary protein-ligand-ion conjugates. The NMRD profiles (the magnetic field dependence of 1/T1) of solutions of the ternary conjugates differ greatly from those of the corresponding binary ligand-metal-ion complexes, both in magnitude and functional form, exhibiting 5- to 10-fold greater relaxivities and prominent peaks near 20 MHz. The inference is that the protein-bound chelates are relatively rigidly attached to the macromolecules. The structure and metal ion affinities of these novel conjugates, as well as the relevance to contrast enhancement in NMR imaging, is discussed.     

Thermoluminescence studies of LiSrBO3:RE3+ (RE=Dy,Tb, Tm and Ce)

The polycrystalline samples of LiSrBO₃:RE³⁺ were synthesized by high-temperature solid-state reaction. The influence of different rare earth dopants, i.e. Dy³⁺, Tb³⁺, Tm³⁺ and Ce³⁺, on thermoluminescence (TL) of LiSrBO₃ phosphor was discussed. We also investigated some dosimetric characteristics of LiSrBO₃:Tm³⁺. The effect of the concentration of Tm³⁺ on the TL intensity was investigated and the result of which showed that the optimum mole fraction of Tm³⁺ was 1%. The TL kinetic parameters of LiSrBO₃:0.01Tm³⁺ were calculated by the computer glow curve deconvolution (CGCD) method. We also studied the three-dimensional (3D) TL emission spectrum of LiSrBO₃:0.01Tm³⁺ under gamma-ray irradiation. The dose-response of LiSrBO₃:0.01Tm³⁺ to γ-ray was linear in the range from 1 to 400 m Gy.     

Novel 3+1 mixed-ligand Technetium-99m complexes carrying dipeptides as monodentate ligands

Novel mixed ligand oxotechnetium complexes of the type [99mTcO(SSS)(SR)], in which the SR monodentate ligand is derived from dipeptides gly-gly, phe-gly and ala-gly, have been synthesized. These complexes, which have a molecular weight above 300, a lipophilic moiety, [TcO(SSS)]+, and an ionizable group separated from the lipophilic moiety by a spacer, have been obtained in 70-95% radiochemical yield. These compounds were prepared using 99mTc-tartrate as the precursor and Sn2+ as the reducing agent. The identity of the [99mTcO(SSS)(SR)] complexes has been established by HPLC comparison with the analogous oxorhenium complexes. The nature of the monodentate co-ligand strongly affects the stability of the 99mTc-complexes and their biodistribution. Complex 3b is the most stable in vitro presenting the highest blood clearance, a high liver uptake and a selective hepatobiliary excretion (54.5% ID at 15 min post-injection, and 69.3% ID at 60 min post injection). The results obtained show that 3b have reasonable stability and in vivo properties that may be useful for peptide labeling.     

B1+ compensation in 3T cardiac imaging using short 2DRF pulses.

The purpose of this study was to determine if tailored 2DRF pulses could be used to compensate for in-plane variations of the transmitted RF field at 3T. Excitation pulse profiles were designed to approximate the reciprocal of the measured RF transmit variation where the variation over the left ventricle was approximated as unidirectional. A simple 2DRF pulse design utilizing three subpulses was used, such that profiles could be quickly and easily adapted to different regions of interest. Results are presented from phantom and in vivo cardiac imaging. Compared with conventional slice-selective excitation, the average flip angle variation over the left ventricle (measured as the standard deviation divided by the mean flip angle) was reduced with P < 0.001 and the average reduction was 41% in cardiac studies at 3T.     

Stability studies on (99m)technetium(III) complexes with tridentate/monodentate thiol ligands and phosphine ('3 + 1 + 1' complexes).

The preparation and characterisation of 3 + 1 + 1 technetium complexes of the general formula [Tc(SES)(RS)(PMe2Ph)] (SES = tridentate dithiol ligand, E = S, O, NMe; RSH = monothiol ligand) at the n.c.a. level is described. The Tc(III) complexes are prepared in a one-step procedure starting from pertechnetate in yields of 85-95% of radiochemical purity. A comparison of their chromatographic data with the fully characterised 99Tc complexes indicate the identity of the investigated compounds. Stability studies show that the 99mTc complexes undergo some alteration in solution. They are oxidised to the 3 + 1 oxotechnetium (V) complexes and/or decompose in aqueous solution. In challenge experiments performed with glutathione, exchange of the monothiolato ligand occurs in the same manner as known for the 3 + 1 complexes.     

以“3＋2＋1”模式实现优质医疗资源下沉， 让老百姓在“家门口”享受三甲医院医疗服务

【摘要】与成都市郫都区人民医院建立紧密型医共体的成都市郫都区人民医院安德分院新院区在2020年7月1日全面开诊,这意味着在区域医共体新模式下,将三甲医院优质医疗资源直接送到了老百姓“家门口”,是一份实实在在的民生大礼。成都市郫都区人民医院安德分院充分利用区域医共体这个平台,以“三个相通”“两个帮扶”“一个联动”模式实现了与成都市郫都区人民医院的紧密结合,提高了区域医疗资源使用效率,实现了优质医疗资源下沉,切实解决了基层老百姓看病难、看病贵、看病不方便等问题。     

Number of inner-sphere water molecules in Gd3+ and Eu3+ complexes of DTPA-amide and -ester conjugates

The inner-sphere water coordination number for Eu3+ and Gd3+ complexed with five DTPA analogs, in which one or two terminal carboxylate groups are functionalized as propyl amides or propyl esters, have been studied using phosphorescence lifetime and nuclear magnetic relaxation dispersion (NMRD) measurements. Both methods show that the water coordination number does not increase above that observed for the analogous DTPA complexes. The phosphorescence lifetime results indicate that all five Eu3+ complexes have one inner-sphere water molecule at 25 degrees C. The NMRD profiles for three of the Gd3+ complexes at 25 degrees C are also consistent with one inner-sphere water molecule, whereas two complexes have profiles consistent only with a mixture of complexes, 50% containing a single water molecule and 50% with none. Lowering the temperature alters the population of these species such that all five Gd3+ complexes have significantly less bound water on average at 5 degrees C. These results explain the anomalous temperature dependencies of the NMRD curves reported previously for the Gd(DTPA)-protein conjugates. We suggest that the Gd(DTPA)-conjugate systems have a fluxional coordination sphere whereby the amount of inner-sphere coordinated water varies from near zero at 5 degrees C to a high of two near 37 degrees C.     

Recovery to +1Gz and +2Gz following +Gz-induced loss of consciousness: operational considerations

With the development of aircraft autorecovery technology, the need to understand the effects of potential inflight recovery profiles on human physiology has become important. Eight male volunteer subjects were exposed to +7Gz with an onset rate of 6 G.s-1 until they were unconscious. The subjects did not wear anti-G suits and did not perform anti-G straining maneuvers. The subjects controlled the centrifuge utilizing an F-16A stick, thereby deliberately self-inducing their unconsciousness. Following +Gz-induced loss of consciousness (G-LOC), recovery to the usual +1Gz level was compared to recovery to a +2Gz level by comparing absolute, relative, and total incapacitation times. The mean (+/- S.D.) absolute incapacitation time (period of unconsciousness) was 11.9 +/- 2.9 s for recovery to a +1Gz level and 12.9 S (+/- 6.9 S.D.) for recovery to a +2Gz level. The mean relative incapacitation time (period of confusion/disorientation) was 3.6 +/- 2.3 s for recovery to a +1Gz level as compared to 2.9 +/- 0.8 s for recovery to a +2Gz level. The total incapacitation time (sum of the absolute and relative incapacitation) was 15.6 +/- 2.7 s for recovery to a +1Gz level and 16.0 s (+/- 6.8 S.D.) for recovery to a +2Gz level. No significant differences in any of the incapacitation times were found when comparing recovery to +1Gz and +2Gz. The mean time from the onset of +Gz-stress to the onset of unconsciousness was approximately 7 s.(ABSTRACT TRUNCATED AT 250 WORDS)     

Stability versus reactivity of ”3+1” mixed-ligand technetium-99m complexes in vitro and in vivo

”3+1” technetium-99m mixed-ligand complexes as relevant to the development of a third generation of ^99mTc radiopharmaceuticals were investigated in vivo and in vitro in the blood of rats. Surprisingly, in whole blood the complexes, which proved to be stable in saline, PBS of pH 7.4 and in plasma, were converted into two radioactive, more hydrophilic metabolites. Small structural differences in the complex molecule have a profound influence on the rate of metabolism of the complexes. To obtain an understanding of this unexpected reactivity, transchelation reactions with glutathione (GSH) were hypothesized and this hypothesis substantiated by challenge experiments carried out with a series of ^99mTc and analogous rhenium complexes and GSH. In vitro studies in human plasma, whole blood and erythrocytes also revealed conversion of the complexes, though, at a much slower rate. Structural parameters influencing the stability of the complexes and consequences for the radiopharmaceutical design are discussed. Received 28 January and in revised form 14 April 1998     

ESR study of Gd3+ and Mn2+ ions sorbed on hydroxyapatite.

Adsorption of Gd3+ and Mn2+ into hydroxyapatite (HAP (Ca5(PO4)3(OH)2) was studied by ESR, ion chromatography and ICP-AES to investigate the U-uptake model. HAP absorbed Gd3+ via a cation exchange reaction and resulted in a signal width of 240 mT. The growth of the thermally stable Gd3+ signal in HAP was also fitted by saturation and diffusion equations. The ESR signals of Gd3+ and Mn2+ were observed overlapping the CO2- signals, however, the dose-response curves of the CO2- signal were similar to that of control HAP.     

经皮穿刺椎间盘激光气化减压术联合臭氧介入治疗脊髓型颈椎病

目的探讨经皮穿刺椎间盘激光气化减压术联合臭氧介入治疗治疗脊髓型颈椎病的临床价值。方法脊髓型颈椎患者212例，颈椎间盘突出263个97例行单纯PLDD治疗，将波长为980nm半导体激光光纤（直径200nm）在透视下插入钩椎关节内进行气化（功率5W，能量200—400J）。115例行PLDD联合臭氧治疗，即在上述PLDD治疗后5min在光纤插入部位用注射器吸取臭氧5—20ml注入病变椎间盘。追踪1—24个月，以Macnab标准判定疗效。结果PLDD组优良率76．3％，联合治疗组优良率91．3％，差异有显著意义（P〉0．05）。结论经皮穿刺激光气化减压术联合臭氧介入治疗脊髓型颈椎病安全、微创、痛苦小、恢复快。     

Change of voice characteristics during +3 Gz acceleration

BACKGROUND: This study was performed to test the feasibility of an experimental approach for assessing voice changes during exposure to increased +Gz acceleration. Such changes are probably due to mechanical alterations of the structures involved in voice production. This may be relevant to automatic speech analysis for flight control. Because voice control by means of auditory feedback may compensate for acceleration effects, the investigations included conditions with masked auditory feedback. METHOD: Four male subjects read standard speech test material while seated in a human centrifuge both during sustained +3 Gz acceleration and in a reference condition. Both test runs were repeated with masking of the auditory feedback by a white noise presented via headphones. Microphone and acceleration signals were recorded on a PC-based dynamic signal acquisition board. Long-time average spectra (LTAS), fundamental frequency (F0), and the frequency of the first, second, and third formant (F1, F2, F3) of the vowels /a/, /o/, and /i/ were extracted from the microphone signal for the different conditions. RESULTS: LTAS clearly differed between the masking conditions, but not between reference and +3 Gz conditions. F0 clearly rose with auditory masking and showed a small increase under +3 Gz acceleration. Several effects of +3 Gz acceleration on formant frequencies were found, all of rather small magnitude. Increased acceleration lowered F2 for the vowel /i/. A decrease of F3 was observed for vowels /i/ and /o/. CONCLUSION: This pilot study has shown the feasibility of an experimental approach to assessing voice changes during exposure to increased +Gz acceleration. Exposure to +3 Gz showed small effects on FO and several formant frequencies. A definitive forthcoming study should assess the significance of these effects by investigating a greater number of subjects during exposure to acceleration higher than +3 Gz.     

+Gz暴露后大鼠脑皮层Beclin-1和LC3的表达变化

目的 探讨+ Gz暴露后大鼠脑皮层自噬相关标志物Beclin-1和LC3表达的变化.方法 雄性SD大鼠30只,随机分为对照组、+ 10 Gz/3 min暴露组和+10 Gz/5 min暴露组.+Gz暴露组分别于暴露后6h、24 h取脑皮层组织,采用RT-PCR和Western Blot方法分别测定自噬相关基因Beclin-1和LC3 mR-NA及蛋白表达的变化.结果 与对照组相比,两组+Gz暴露后6h脑皮层Beclin-1和LC3 mRNA及蛋白表达均显著增强(P＜0.01),暴露后24 h其表达量仍显著增加(P＜0.05).+10 Gz/5 min组较+10Gz/3 min组表达增加更为明显(P＜0.05).结论 +10 Gz暴露可诱导脑皮层自噬相关标志物Beclin-1和LC3的高表达,提示高+Gz应激促进了脑皮层自噬的发生,且随着暴露时间的延长,自噬表达更显著.     

Ligand-exchange reaction of labile "3 + 1"99mTc(V) complexes with SH group-containing proteins.

The reactivity of labile 3 + 1 mixed-ligand 99mTc complexes of the type [99mTcO(SES)(RS)] with SES being a tridentate dithiol ligand and glutathione or dimethylcysteamine as monodentate ligands RSH towards proteins was investigated in vitro and in vivo. It was found that the complexes undergo reversible transchelation reactions with SH group-containing components of blood such as albumin or haemoglobin. High labelling yields were obtained when 3 + 1 complexes with the tridentate SSS ligand were used. The biodistribution of blood proteins labelled by ligand-exchange reaction with the [99TcO(SSS)] or [99mTcO(SNMeS)] core was studied and compared with the in vivo distribution of the labile 3 + 1 complexes containing glutathione as monodentate ligand.     

含Rumex K-1草粉、苜蓿草粉、Rumex K-1草粉+石粉三种日粮对家兔生长消化影响的比较

将18只家兔分成三组,A组家兔饲喂40％苜蓿草粉配制的免用颗粒饲料,B组饲喂40％Rumex k-1草粉配制的颗粒日粮,C组饲喂在B组日粮基础上添加3.3％石粉的日粮,以比较Rumex K-I草粉和苜蓿草粉的营养价值和添加石粉对提高Rumex K-1草粉营养价值的作用。结果表明:A、B、C组家兔对3种日粮的采食量分别为159.81±6.08,128.96±8.96和151.11±11.56 g/免/d,各组平均日增重分别为32.61±1.63,30.61±1.98和35.58±4.22g/免/d,有机物消化率(％)分别为59.50±1.12,70.85±1.97和69.06±2.02,粗蛋白消化率(％)分别为68.30±2.81,74.46±2.50和73.33±3.40。与苜蓿草粉日粮比,家免对含Rumex K-1日粮采食量低19.3％(P<0.01),体增重减慢6.5％(P>0.05),而有机物和粗蛋白消化率却分别提高19％(P<0.01)和9.6％(P<0.01)。表明家兔对Rumex K-1草粉日粮具有良好的消化性,但适口性较差,从而影响动物的生长性能。往Rumex K-1日粮中添加石粉,可使家免的采食量增加17.2％(P<0.01),日增重提高16.2％(P<0.05),是提高采食量、从而改善家兔营养的有效办法,可以消除饲喂Rumex K-1草粉时的不良作用。     

CD3+CD56+NKT细胞在中晚期胃癌治疗中的临床疗效观察

目的：评估CD3^＋CD56^＋NKT细胞治疗73例中晚期胃癌的疗效及不良反应。方法．St细胞分离机采集患者外周血单个核细胞，加入细胞因子rhINF-γ、rhIL-2、rhIL-1及CD3McAb培养，10d后定向诱导成CD3^＋CD56^＋NKT细胞，分次回输给患者，每疗程回输细胞总数为（5～10）&#215;10^9个。治疗4w后，用流式细胞仪检测患者外周血T细胞亚群状态及细胞因子水平，以评价细胞免疫功能，结合临床指标综合评价疗效，同时观察不良反应。结果：在73例接受治疗的患者中，部分缓解（PR）＋微效（MR）为37例（50．68％），稳定（SD）21例（28．76％），进展（PD）15例（20．54％）；CD3^＋CD56^＋NKT细胞的百分比在治疗后均较治疗前显著增高（P〈O．05），且72．60％（53例）的患者CD4／CD8比例调整至正常；80．82％（59例）的患者治疗后Th1类细胞因子分泌增加，61.64％（45例）的患者Th1／T11=2细胞因子比例恢复平衡；治疗后42例食欲增加，51例体力及睡眠改善，23例体重回升大于治疗前体重的5％；输注后的副反应包括寒颤、发热、呕吐、兴奋失眠、皮疹、疲乏，经对症处理后短时缓解，无1例出现毛细血管渗漏综合征（SCLS）及实质脏器的损害。结论：过继性CD3^＋CD56^＋NKT细胞输注治疗能显著调整中晚期胃癌患者的免疫功能，改善临床症状，是一种安全、有效的辅助治疗手段。