A field-focusing device to increase power output of ThermoRod trade mark implants for thermal ablation of tissue

Induction heating of small, cylindrical ferromagnetic implants (1.4 cm long and 1 mm in diameter) is a method for treating deep-seated tumors. These implants, or ThermoRods trade mark, are placed within a lesion in 1-cm(2) arrays and are exposed to an alternating magnetic field. The implants absorb energy from that field and transfer it as heat to the surrounding tissue. Each ThermoRod trade mark offers approximately 400 mW of power, and to kill cells, the target temperature must be greater than 42 degrees C. In this work, a magnetic field-focusing device is employed to concentrate the induced magnetic flux toward a local region near the base of the prostate to increase the power output of proximal ThermoRods trade mark. This, in turn, allows for more complete thermal ablation of lesions near the base of the prostate where the heat-sink characteristics of the bladder can cause significant power losses. Boundary element analysis and in vitro testing have shown that the use of a ferrofluid-based field-focusing device can lead to a significant increase in power output of approximately 25% and 13%, respectively, of proximal ThermoRods trade mark. These preliminary results indicate that the incorporation of such a ferrofluid-based focusing device into ThermoRod trade mark treatments is promising for the avoidance of significant power loss and for assuring complete thermal ablation of prostatic lesions.     

Facilitating visuospatial attention for the contralateral hemifield by repetitive TMS on the posterior parietal cortex

Previous studies have demonstrated that repetitive transcranial magnetic stimulation (rTMS) could modulate the visuospatial functions. In this study, we investigated the effect of off-line high frequency subthreshold rTMS, when applied over the right or left posterior parietal cortex (PPC), on the visuospatial attention of the bilateral hemispaces. The subjects underwent visuospatial tasks before and immediately after receiving 1000 pulses of 10 Hz rTMS for a period of 20 min, and their responses were recorded. Our results demonstrated that the high frequency rTMS applied over the PPC produced facilitative effects on the visuospatial attention to the contralateral hemispace. The inhibitory effect to the ipsilateral hemispace was noticeable only in the left PPC.     

卫生资源优化配置的伦理要求

1　医学目的和卫生资源的配置卫生资源的配置问题 ,不是一个孤立的问题 ,它是同一定的医学目的联系在一起的 ,一定的医学目的 ,对卫生资源的配置起着导向作用 ,是为一定的医学目的服务的。传统医学由于受科学技术和社会发展的局限 ,以及受传统疾病模式的影响 ,只能把医学的目的定位于对疾病的治疗上 ,向一个消防队员一样 ,哪里有火、火大 ,就把目标投向哪里 ,从而终日疲于奔命 ,和这种医学目的相适应 ,这时的卫生资源配置就只能是把大部分卫生资源用于对疾病的诊治上。随着社会的发展 ,疾病模式发生了显著的变化 ,这种救火式的医疗 ,致使一…     

A rubrofusarin gentiobioside isomer from roastedCassia tora

From the roasted seeds ofCassia tora L., a new naphthopyrone glycoside was isolated and characterized as 10-[(β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl)oxyl-5-hydroxy-8-methoxy-2-methyl-4H-naphtho [1,2-b]pyran-4-one(isorubrofusarin gentiobioside). Along with isorubrofusarin gentiobioside, alaternin and adenosine were isolated and identified.     

Inhibition of C-terminal O-methyltransferase by a rat liver cytosolic peptide

The activity of S-famesylcysteine O-methyltransferase was assayed by incubating the enzyme with a syntheticin vitro substrate, [N-acetyl-S-trans, trans-famesyl-L-cysteine (AFC)], together with S-adenosyl-L-[methyl-¹⁴C]methionine. The resulting methylesterification product, [N-acetyl-S-trans, trans-famesyl-L-cysteine (methyl-¹⁴C) ester (AFCME)], was then analyzed either directly on HPLC or by converting the AFC[methyl-¹⁴C]ME to [methyl-¹⁴C] alcohol by basehydrolysis. Employing these two analytical methods, it was established that a peptide purified from rat liver cytosol fraction [Int. J. Biochem., 25, 1157 (1993)] strongly inhibited the above enzyme activity with IC₅₀ of 7.1X10^?8 M. Also, the S-famesylcysteine O-methyltransferase from several human colon cancer cells was also equally inhibited by the peptide.     

Hydrolysis kinetics of metampicillin by high performance liquid chromatography

The hydrolysis of metampicillin to ampicillin was investigated using high performance liquid chromatography. We developed the simultaneous determination of metampicillin and ampicillin using a Zorbax CN column and 5% acetonitrile and 8% methanol in 0.02 M phosphate buffer (pH 7.0) as mobile phase. Metampicillin was hydrolyzed to ampicillin with half life of 41.5 min at physiological pH and temperature. In acidic pH, metampicillin was rapidly hydrolyzed to ampicillin within a chromatographic separation.     

Synthesis of 4-hydroxy-1-thiocoumarin derivatives-1: An efficient synthesis of thioflocoumafen

An efficient procedure for the preparation of 4-hydroxy-3-{1,2,3,4-tetra-hydro-3-[4-(4-triflu-oromethylbenzyl oxy)phenyl]-1-naphthyl}thiocoumarin (thioflocoumafen, 1a and 1b) is described. The key step in the synthesis involves the condensation reaction of 3-(4-methoxyphenyl)-1-tetralol (2) with 4-hydroxy-1-thiocoumarin (3).     

Inducible nitric oxide synthase inhibitors fromMelia azedarach var.Japonica

In bioassay-guided search for inducible nitric oxide synthase (iNOS) inhibitory compounds from higher plants of South Korea, two beta-carboline alkaloids, 4-methoxy-1-vinyl-beta-carboline (1) and 4,8-dimethoxy-l-vinyl-beta-carboline (2) have been isolated from the cortex of Melia azedarach var. japonica. The structures of these compounds were elucidated on the basis of spectroscopic data. Compounds 1 and 2 showed marked inhibitory activity of iNOS on LPS- and interferon-gamma-stimulated RAW 264.7 cells.     

Esters of substituted benzoic acids as anti-thrombotic agents

Aliphatic esters of protocatechuic acid (PA,1), vanillic acid (VA,9) and gallic acid (GA,18) were prepared and their anti-thrombotic effects were evaluated in the mouse model of thrombosis. The aliphatic groups included methyl, ethyl,n-propyl,i-propyl,n-butyl,i-butyl,n-amyl and cyclohexyl.n-Amyl ester of PA (7), i-propyl and cyclohexyl esters of VA (13 and17 respectively) and ethyl ester of GA (20) treatment significantly lowered the death rate and increased the recovery from paralysis due to the thrombotic challenge. From the limited analogs available, it was tentatively concluded that the structural conformation, where carboxy oxygen (=O or-O^?) of the carboxyl group (COOH) at C₁ and the oxygen function at C₃ (either OH or OCH₃) are closely situated, is favorable for the esters of PA, VA and GA to be more antithrombotic.