Harmonic hepatic US with microbubble contrast agent: initial experience showing improved characterization of hemangioma, hepatocellular carcinoma, and metastasis

PURPOSE

To characterize blood flow in focal hepatic lesions with harmonic ultrasonographic (US) imaging and a microbubble contrast agent.

MATERIALS AND METHODS

Thirty patients with known hepatic masses were examined after injection of a perfluorocarbon microbubble agent. Tumor vascularity was assessed with continuous, harmonic gray-scale imaging with a low mechanical index (MI). Tumor vascular volume was assessed with brief, high-MI insonation called interval-delay imaging, which caused microbubble destruction. As the total contrast agent volume in the liver reflects the total vascular volume, quantitation of lesion enhancement relative to normal hepatic enhancement helped determine the vascular volume of the tumor relative to that of normal parenchyma.

RESULTS

Low-MI continuous harmonic imaging showed lesional vessels in hepatocellular carcinomas, minimal or no vessels in hemangiomas, and variable vascularization in metastases. High-MI interval-delay imaging showed greater enhancement in hepatocellular carcinomas than in normal liver (P <.02) and showed less enhancement in hemangiomas than in normal liver (P <.02). Enhancement in metastases was greater in the margins than in the center; as a result, the lesions appeared smaller (P <.03) and less well defined on the interval-delay images.

CONCLUSION

Contrast-enhanced harmonic imaging appears superior to conventional Doppler US for hepatic mass characterization. Low-MI continuous and high-MI interval-delay imaging can help assess tumor vascular pattern and microvascular volume.

[A molecular cytogenetic study on chromosome anomalies of chronic myeloid leukemia]

OBJECTIVE

To study the bcr/abl fusion gene in chronic myeloid leukemia (CML) cases with Philadelphia chromosome(Ph) negative, and variant Ph translocations and other chromosome anomalies.

METHODS

The status of bcr/abl fusion gene in 8 kinds of chromosome anomalies was tested with dual-color fluorescence in situ hybridization (D-FISH) technique.

RESULTS

The positive hybridization was demonstrated in 3 cases of variant Ph CML and other 7 cases of standard Ph, respectively. In 2 cases of Ph-negative CML, one case that had karyotype such as 46,XY,t(9;18) showed positive hybridization, the other case with 46,XY,inv(2) showed negative result.

CONCLUSION

The result demonstrates that D-FISH technique is reliable for detecting bcr/abl fusion gene. The existence of negative bcr/abl fusion gene CML implies that some other initial events inducing CML might have occurred in such cases.

[A Carnobacterium-like organism isolated form a patient with multiple bacterial synergistic gangrene]

An atypical lactic-acid producing gram positive rod Y6 strain was studied in this report, which was isolated form clinic sample of a patient with multiple bacterial synergistic gangrene, and could not be identified by routine method. A 1.5 kb of 16S rDNA of Y6 strain was synthesized and sequenced. Comparative 16S rDNA sequence analyses revealed that stain Y6 is most closely related to the genus of Carnobacterium. The overall similarity value between Y6 strain and Carnobacterium species are 93% to 97%. The signature nucleotides in 16S rDNA primary sequence of strain Y6 and that of genus of Carnobacterium were identical. The biological features of Y6 strain are very similar to that of Carnobacterium, such as lactic acid as main end product of in PYG broth, no gas produced form fermentation of glucose, catalase negative, no motility. Data suggested that Y6 strain is very similar to the genus of Carnobacterium, of which no strain has been isolated form clinical sample so far. Based on the results obtained, we names Y6 strain as Carnobacterium-like organism.

Infusion versus bolus of an ultrasound contrast agent: in vivo dose-response measurements of BR1

RATIONALE AND OBJECTIVES

To determine the efficacy of an ultrasound contrast agent infusion using Doppler intensitometry estimation of backscatter enhancement in blood.

METHODS

Multiple intravenous injections of BR1 (SonoVue) were performed in chronic dog studies, using bolus (0.05-2 mL) and infusion (3-40 mL/h during 6 minutes) administration. The pulsed Doppler signal from the femoral artery was recorded and analyzed for mean Doppler power and integrated fractional enhancement.

RESULTS

For bolus injection, time-intensity curves exhibited a rapid first pass (peak 30 dB for 0.45 mL) followed by a slower washout. Integrated fractional enhancement exhibited a linear relation with the dose (R2 = 0.99). For infusion administration, peak enhancement increased with the infusion rate from 8 to 22 dB. At rates exceeding 30 mL/h, the enhancement was stable with a plateau-like pattern.

CONCLUSIONS

Infusion of BR1 is easily achieved and allows the duration of enhancement to be increased as long as desired. Stable enhancement is obtained for rates greater than 30 mL/h.

The effect of electroacupuncture on auditory P300 potential in mongolism cases

In treating children with mongolism (Down's syndrome) with electroacupuncture, the latent period of P3 is shortened, which shows that the cerebral reaction to external stimulus in classification, encoding and recognition is accelerated. Along with the elevated P3 amplitude, the cerebrum is more capable of processing the external information, showing improvement of the mental state.

The third lumbar transverse process syndrome treated by electroacupuncture at huatuojiaji points

32 cases of the third lumbar transverse process syndrome were treated mainly by electroacupuncture at Huatuojiaji points of the first and second lumbar vertebrae, and another 30 cases of the syndrome by conventional acupuncture as the controls. The results showed that treatment by electroacupuncture at Huatuojiaji points was superior in analgesic effect and clinical total effective rate to that by conventional acupuncture. It is considered that the mechanism of treatment by electroacupuncture at Huatuojiaji points is related to the trunk of posterior ramus of the spinal nerve where the points are located.

[Effects of places and stages on the contents of ganoderic acid B from Ganoderma lucidum]

The paper reports the assay of ganoderic acid B from Ganoderma lucidum in different places and stages by means of HPLC. The results show that contents of ganoderic acid B from different cultured places have differnces, different stages have effect on the amount too.

[Kinetics of the Ca(2+)-activated K+ channel in Ca2+ induced cortex neurons damage]

Ca(2+)-activated K+ channels were studied by using the patch clamp technique of single channel recordings from the primary culture fetal SD rat cortex neurons. Besides their physiologic characters, the effects of increasing cytosolic and cytoplasmic Ca2+ triggered neuronal damage were also studied. The results showed that Kca with conductance around 170PS was predominant in the rat cortex neurons. These channels almost did not open at physiologic intracellular free Ca2+ concentration (10(-8) mol/L), but was extremely activated at intracellular free Ca2+ concentration (10(-6) mol/L). So the open probabilities of the KCa in the cortex neurons obviously depended on the concentration of cytoplasmic Ca2+ and membrane potential. The KCa activated by increasing of intracellular Ca2+ during the early stage of anoxia may be a protective reaction of ischemic neurons.

Interpolation methods for time-delay estimation using cross-correlation method for blood velocity measurement

The cross-correlation method (CCM) for blood flow velocity measurement using Doppler ultrasound is based on time delay estimation of echoes from pulse-to-pulse. The sampling frequency of the received signal is usually kept as low as possible in order to reduce computational complexity, and the peak in the correlation function is found by interpolating the correlation function. The parabolic-fit interpolation method introduces a bias at low sampling rate to the ultrasound center frequency ratio. In this study, four different methods are suggested to improve the estimation accuracy: (1) Parabolic interpolation with bias-compensation, derived from a theoretical signal model. (2) Parabolic interpolation combined with linear filter interpolation of the correlation function. (3) Parabolic interpolation to the complex correlation function envelope. (4) Matched filter interpolation applied to the correlation function. The new interpolation methods are analyzed both by computer simulated signals and RF-signals recorded from a patient with time delay larger than 1/f(0), where f(0) is the center frequency. The simulation results show that these methods are more accurate than the parabolic-fit method. From the simulation, the worst estimation accuracy is about 1.25% of 1/f(0) for the parabolic-fit interpolation, and it is improved by the above methods to less than 0.5% of 1/f(0) when the sampling rate is 10 MHz, the center frequency is 2.5 MHz and the bandwidth is 1 MHz. This improvement also can be observed in the experimental data. Furthermore, the matched filter interpolation gives the best performance when signal-to-noise ratio (SNR) is low. This is verified both by simulation and experimentation.

[Observation of clinical effect of acupuncture on vascular dementia and its influence on superoxide dismutase, lipid peroxide and nitric oxide]

OBJECTIVE

To observe the clinical effect of electroacupuncture and acupuncture on vascular dementia (VaD) and the influence on superoxide dismutase (SOD), lipid peroxide (LPO) and nitric oxide (NO) levels.

METHODS

Forty-six cases of VaD were randomly divided into two groups, the electroacupuncture group (EA group) and the acupuncture group (AP group). Assessment of Hasgawa's dementia scale (HDS), functional activities questionnaire (FAQ) and neurologic deficit scoring were done before and after treatment, and the changes on SOD, LPO and NO levels were observed.

RESULTS

After treatment, in the EA group, the HDS elevated, the FAQ lowered, SOD increased and LPO and NO decreased significantly, as compared with before treatment, P < 0.01. But these parameters were not changed significantly in the AP group after treatment. The clinical symptoms were improved in both groups, but the reduction on neurologic deficit score was not significant. The total effective rate of the EA group was higher than that of the AP group.

CONCLUSION

The immediate effect of electroacupuncture was superior to that of acupuncture, suggesting that the electroacupuncture was more effective in promoting the intelligence recovery than acupuncture.

Onset of catalytic activity of gold clusters on titania with the appearance of nonmetallic properties

Gold clusters ranging in diameter from 1 to 6 nanometers have been prepared on single crystalline surfaces of titania in ultrahigh vacuum to investigate the unusual size dependence of the low-temperature catalytic oxidation of carbon monoxide. Scanning tunneling microscopy/spectroscopy (STM/STS) and elevated pressure reaction kinetics measurements show that the structure sensitivity of this reaction on gold clusters supported on titania is related to a quantum size effect with respect to the thickness of the gold islands; islands with two layers of gold are most effective for catalyzing the oxidation of carbon monoxide. These results suggest that supported clusters, in general, may have unusual catalytic properties as one dimension of the cluster becomes smaller than three atomic spacings.

[Differentiation of original plants of xihuangcao by using random amplified polymorphic DNA (RAPD) markers]

Four original plants of Xihuangcao have been differentiated from each other by random amplified polymorphic DNA polymorphism. The results show that RAPD technique is an effective method for identification and quality study of Chinese medicinal materials.

Metabolic engineering of bacteria for ethanol production

Technologies are available which will allow the conversion of lignocellulose into fuel ethanol using genetically engineered bacteria. Assembling these into a cost-effective process remains a challenge. Our work has focused primarily on the genetic engineering of enteric bacteria using a portable ethanol production pathway. Genes encoding Zymomonas mobilis pyruvate decarboxylase and alcohol dehydrogenase have been integrated into the chromosome of Escherichia coli B to produce strain KO11 for the fermentation of hemicellulose-derived syrups. This organism can efficiently ferment all hexose and pentose sugars present in the polymers of hemicellulose. Klebsiella oxytoca M5A1 has been genetically engineered in a similar manner to produce strain P2 for ethanol production from cellulose. This organism has the native ability to ferment cellobiose and cellotriose, eliminating the need for one class of cellulase enzymes. The optimal pH for cellulose fermentation with this organism (pH 5.0-5.5) is near that of fungal cellulases. The general approach for the genetic engineering of new biocatalysts has been most successful with enteric bacteria thus far. However, this approach may also prove useful with Gram-positive bacteria which have other important traits for lignocellulose conversion. Many opportunities remain for further improvements in the biomass to ethanol processes. These include the development of enzyme-based systems which eliminate the need for dilute acid hydrolysis or other pretreatments, improvements in existing pretreatments for enzymatic hydrolysis, process improvements to increase the effective use of cellulase and hemicellulase enzymes, improvements in rates of ethanol production, decreased nutrient costs, increases in ethanol concentrations achieved in biomass beers, increased resistance of the biocatalysts to lignocellulosic-derived toxins, etc. To be useful, each of these improvements must result in a decrease in the cost for ethanol production. Copyright 1998 John Wiley & Sons, Inc.

[Hemorheologic change after strong blood flow disturbance caused by gunshot and its influence on the prognosis of the wounded animals]

Three types of experimental models were used in this study: 1. Both thighs of dogs were wounded by 5.56 mm bullet. 2. Femoral artery and vein were tied at the time of wounding. 3. Shock caused by simply bleeding the dogs' femoral arteries. We observed the characteristics of change hemorheology and analyzed its effects on the wounded dogs. The results showed that strong blood flow disturbances always brought about hemorheologic changes such as rapidly increased blood viscosity and red cell's aggregation index and the simultaneous phenomenon of blood concentration. These may be related to extensive endothelium injury and destruction of a number of blood cells caused by disturbance wave. The above change may give rise to abnormality of microcirculation and disturbance of matter transmission; in that sense, it may provide the physiopathologic basis for the occurrence and development of the complication.

Isolation and molecular characterization of high-performance cellobiose-fermenting spontaneous mutants of ethanologenic Escherichia coli KO11 containing the Klebsiella oxytoca casAB operon

Escherichia coli KO11 was previously constructed to produce ethanol from acid hydrolysates of hemicellulose (pentoses and hexoses) by the chromosomal integration of Zymomonas mobilis genes encoding pyruvate decarboxylase (pdc) and alcohol dehydrogenase (adhB). Klebsiella oxytoca P2 was constructed in an analogous fashion for the simultaneous saccharification and fermentation of cellulose and contains PTS enzymes for cellobiose. In this study, KO11 was further engineered for the fermentation of cellulose by adding the K. oxytoca casAB genes encoding Enzyme IIcellobiose and phospho-beta-glucosidase. Although the two K. oxytoca genes were well expressed in cloning hosts such as DH5 alpha, both were expressed poorly in E. coli KO11, a derivative of E. coli B. Spontaneous mutants which exhibited more than 15-fold-higher specific activities for cellobiose metabolism were isolated. The mutations of these mutants resided in the plasmid rather than the host. Three mutants were characterized by sequence analysis. All contained similar internal deletions which eliminated the casAB promoter and operator regions and placed the lacZ Shine-Dalgarno region immediately upstream from the casA Shine-Dalgarno region. KO11 harboring mutant plasmids (pLOI1908, pLOI1909, or pLOI1910) rapidly fermented cellobiose to ethanol, and the yield was more than 90% of the theoretical yield. Two of these strains were used with commercial cellulase to ferment mixed-waste office paper to ethanol.

[Simulation of a decoupling generalized predictive control algorithm for temperature-humidity system]

A decoupling generalized predictive control algorithm was presented in this paper. This algorithm was proposed to control the temperature-humidity system of a practical air-conditioning environmental chamber. By introducing absolute humidity as an intermediate variable, temperature and humidity of the system can be decoupled. Then the two decoupled systems are controlled by generalized predictive control (GPC) algorithm at different sample rates. Many simulation experiments demonstrated the effectiveness of the algorithm. Besides, decoupling of temperature and humidity will be extremely helpful to the application of GPC on the real system. This is also the effective method to control the temperature and humidity system.

Extracellular melibiose and fructose are intermediates in raffinose catabolism during fermentation to ethanol by engineered enteric bacteria

Contrary to general concepts of bacterial saccharide metabolism, melibiose (25 to 32 g/liter) and fructose (5 to 14 g/liter) accumulated as extracellular intermediates during the catabolism of raffinose (O-alpha-D-galactopyranosyl-1, 6-alpha-D-glucopyranosyl-beta-D-fructofuranoside) (90 g/liter) by ethanologenic recombinants of Escherichia coli B, Klebsiella oxytoca M5A1, and Erwinia chrysanthemi EC16. Both hydrolysis products (melibiose and fructose) were subsequently transported and further metabolized by all three organisms. Raffinose catabolism was initiated by beta-fructosidase; melibiose was subsequently hydrolyzed to galactose and glucose by alpha-galactosidase. Glucose and fructose were completely metabolized by all three organisms, but galactose accumulated in the fermentation broth with EC16(pLOI555) and P2. MM2 (a raffinose-positive E. coli mutant) was the most effective biocatalyst for ethanol production (38 g/liter) from raffinose. All organisms rapidly fermented sucrose (90 g/liter) to ethanol (48 g/liter) at more than 90% of the theoretical yield. During sucrose catabolism, both hydrolysis products (glucose and fructose) were metabolized concurrently by EC16(pLOI555) and P2 without sugar leakage. However, fructose accumulated extracellularly (27 to 28 g/liter) at early stages of fermentation with KO11 and MM2. Sequential utilization of glucose and fructose correlated with a diauxie in base utilization (pH maintenance). The mechanism of sugar escape remains unknown but may involve downhill leakage via permease which transports precursor saccharides or novel sugar export proteins. If sugar escape occurs in nature with wild organisms, it could facilitate the development of complex bacterial communities which are based on the sequence of saccharide catabolism and the hierarchy of sugar utilization.

[Morpho-functional characteristics of vascular endothelial cells affected by hemodynamic factors]

Vascular endothelial cells are most widely distributed of all cells in a living body, which have a complicated structure and many physiologic functions. It was reviewed in present paper that the structural and functional changes in the vascular endothelial cells were as a result of the stimulation from hemodynamics associated machanical factors, such as shear stress cyclic strain, and pressure in physical and pathophysical state.

Cloning of cellobiose phosphoenolpyruvate-dependent phosphotransferase genes: functional expression in recombinant Escherichia coli and identification of a putative binding region for disaccharides

Genomic libraries from nine cellobiose-metabolizing bacteria were screened for cellobiose utilization. Positive clones were recovered from six libraries, all of which encode phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) proteins. Clones from Bacillus subtilis, Butyrivibrio fibrisolvens, and Klebsiella oxytoca allowed the growth of recombinant Escherichia coli in cellobiose-M9 minimal medium. The K. oxytoca clone, pLOI1906, exhibited an unusually broad substrate range (cellobiose, arbutin, salicin, and methylumbelliferyl derivatives of glucose, cellobiose, mannose, and xylose) and was sequenced. The insert in this plasmid encoded the carboxy-terminal region of a putative regulatory protein, cellobiose permease (single polypeptide), and phospho-beta-glucosidase, which appear to form an operon (casRAB). Subclones allowed both casA and casB to be expressed independently, as evidenced by in vitro complementation. An analysis of the translated sequences from the EIIC domains of cellobiose, aryl-beta-glucoside, and other disaccharide permeases allowed the identification of a 50-amino-acid conserved region. A disaccharide consensus sequence is proposed for the most conserved segment (13 amino acids), which may represent part of the EIIC active site for binding and phosphorylation.