[Reversal of cancer multidrug resistance by Chinese medicine Ams-11, Fw-13 and Tul-17]

The aim of this project was to find some kinds of Chinese materia medica as effective agents for in vitro reversal of cancer multidrug resistance. Based on the present authors' previous researches, thirty-two kinds of Chinese medicine as research meterials were selected and examined. Using cell growth inhibit assay, the authors found that three of them--Ams-11, Fw-13 and Tul-17 in the doses free from cytotoxity could enhance the sensitivity of multidrug resistant cells to anti-cancer drugs in a dose-dependent way. It seemed that these three kinds of Chinese medicine might be potential effective reversal agents.

A comparative study of trabecular bone properties in the spine and femur using high resolution MRI and CT

The purpose of this study was to use high resolution (HR) magnetic resonance (MR) and computed tomography (CT) images combined with texture analysis to investigate the trabecular structure of human vertebral and femoral specimens and to compare these techniques with bone mineral density (BMD) in the prediction of bone strength. Twenty-nine bone cubes were harvested from 12 proximal femur cadaver specimens and 29 from 8 spines. HR MR and CT images were obtained, and texture analysis techniques were used to assess trabecular structure. Additionally, BMD, elastic modulus (EM), and maximum compressive strength were determined. R2 for EM versus texture measures computed in the MR images was higher (R2 = 0.27-0.64, p < 0.01) in the spine than in the femur specimens (R2 = 0.12-0.22, p < 0.05). R2 values were similar in the CT images. R2 for EM versus BMD was 0.66 (p < 0.01) in the spine and 0.61 (p < 0.01) in the femur specimens. In the MR images, texture measures combined with BMD in a multivariate-regression model significantly increased R2, while improvement was less significant in the CT images. Thus, texture analysis may provide additional information needed to analyze bone strength and quality.

Experimental studies of electroacupuncture on ventricular fibrillation threshold in rats with acute ischemic myocardium

By ligating the proximate left anterior descend (LAD) of coronary artery and inducing the ventricular fibrillation with electrical stimulation, the preventive effects of electroacupuncture (EA) on ventricular fibrillation were observed. The results showed that the ventricular fibrillation threshold (VFT) of rats with acute ischemic myocardium was raised after acupuncturing some acupoints, which could prevent the occurrence of ventricular fibrillation. Furthermore, the combination of EA and propranolol could enhance the VFT effectively, and they showed a good synergistic effect.

Assessment of trabecular structure using high resolution CT images and texture analysis

PURPOSE

Our goal was to use high resolution (HR) CT images combined with texture analysis to investigate the trabecular structure of human vertebral specimens and to compare these techniques with bone mineral density (BMD) in the prediction of bone strength.

METHOD

HR CT images with a slice thickness of 1 mm were obtained of 28 bone cubes. Four different groups of texture analysis techniques were used to assess these images. In addition, quantitative CT (QCT) was performed and elastic modulus (EM) was determined biomechanically.

RESULTS

R2 between EM and BMD was 0.78 (p < 0.01). R2 values for EM versus most of the texture measures were also significant. Texture measures in addition to measures of BMD in a multivariate regression model significantly increased R2 up to 0.87.

CONCLUSION

In an experimental setting, texture parameters calculated using HR CT images correlated significantly with EM. Combining texture measures with BMD improved the prediction of EM significantly.

[Preparation of chromosomal DNA from whole blood without use of phenol]

We describe in this paper a simple and efficient procedure for preparing peripheral blood DNA without pre-isolation of white blood cells. The method also avoids the hazard of organic solvent extraction. Routinely it yields 20 to 28 micrograms of chromosomal DNA from per ml whole blood. The A260/A280 ratio for DNA sample is 1.80 to 1.85. The undigested DNAs migrate above the 21 kb pair, while the endonucleasedigested samples appear characteristically in the smear form. These data illustrate the consistency and quality of the chromosomal DNA isolated using this procedure. The DNA prepared by this method was used for analysis of beta-thalassemia mutation and prenatal diagnosis in our laboratory.

[Serological survey of human T lymphotropic virus type I (HTLV-1) IgG antibody in south region of Xinjiang]

Human T lymphotropic virus type-1 (HTLV-1) is endemic in southwestern Japan, Seychelles Islands, Caribbean basin, Brazil, and Sub Saharan Africa. Recently, the prevalence of HTLV-1 of domestic source has been reported from Beijing, Fujian and so forth. The object of our study is to know whether the prevalence of HTLV-1 is present in Xinjiang. We collected 2642 serm samples of various ages and different nationalities (Uigur, Han and Khalkhas) from south region of Xinjiang and tested for determination of HTLV-1 IgG antibody by IFA. The results showed that the total positive rate of HTLV-1 IgG was 0.34% (9/2642), of which Uigur nationality was 0.74% (8/1082), Khalkhas nationality was 0.21 (1/471), Han nationality was zero (0/1089). This data indicated that there are HTLV-1 infection among the population of Xinjiang and especially in Uigur and Khalkhas. Why did the minority nationalities have relatively high frequency of HTLV-1 infection? This needs to be studied further.

Reduced ability of transforming growth factor-alpha to induce EGF receptor heterodimerization and downregulation suggests a mechanism of oncogenic synergy with ErbB2

The epidermal growth factor receptor (EGFR) is activated by a variety of ligands including EGF and transforming growth factor-alpha (TGFalpha), whereas no ligand for the homologous ErbB2 oncoprotein has yet been identified. Here we use both an ErbB2 phosphoantibody (aPY1222) and an activation-specific EGFR antibody to show that low concentrations of EGF induce more efficient tyrosine phosphorylation of ErbB2 in A431 cells than does equimolar TGFalpha, while EGFR is more potently activated by TGFalpha. Co-precipitation studies confirm that heterodimerization of activated EGFR and transphosphorylated ErbB2 is readily induced by EGF but not TGFalpha. EGFR downregulation is also more efficiently induced by EGF, suggesting that ligand-dependent modification of ErbB2 may be required to terminate EGFR signalling in cells expressing both receptor types. These findings indicate that EGF and TGFalpha differ in their abilities to induce tyrosine phosphorylation and heterodimerization of ErbB2, and raise the possibility that ErbB2 exerts its oncogenic effect in part by impairing TGFalpha-dependent EGFR downregulation.

A new trabecular region of interest for femoral dual X-ray absorptiometry: short-term precision, age-related bone loss, and fracture discrimination compared with current femoral regions of interest

We defined a new region of interest (ROI) for femoral Ward's triangle, centered on the femoral neck axis including comparatively trabecular-rich bone. Forty-seven premenopausal, 39 healthy postmenopausal, and 35 osteoporotic postmenopausal women with vertebral fractures were evaluated comparing the new with the standard femoral ROIs, using a Hologic QDR-2000. Additionally, spinal dual X-ray absorptiometry (DXA) was performed. The short-term precision error of the new ROI expressed as the root mean square of the coefficient of variations was 1.34% for premenopausal women, 1.69% for healthy postmenopausal women, and 2.46% for osteoporotic postmenopausal women. Bone mineral density (BMD) values of the new ROI correlated highly with those of the standard femoral ROIs (r = 0.91 - 0.96) and the spinal BMD (r = 0.74). Age-related bone loss of the new ROI was 0.75% per year (r = 0.66) in healthy women, which was approximately 1.5 times higher than the bone loss of the standard femoral ROIs, except for Ward's triangle. Regarding the intergroup discrimination, the t-value of the new ROI was similar to the t-value of Ward's triangle, and the intergroup percent decrements in BMD of the new ROI approximated those of Ward's triangle. For discriminating women with vertebral fractures, the new ROI demonstrated odds ratios of 1.6 similar to most ROIs but lower than that of the trochanteric region. The new, substantially trabecular ROI appears to be an alternative to the Ward's ROI traditionally used in femoral DXA having improved short-term precision and comparable sensitivity.

Texture analysis of direct magnification radiographs of vertebral specimens: correlation with bone mineral density and biomechanical properties

RATIONALE AND OBJECTIVES

The authors used direct magnification radiographs, combines with texture analysis, to investigate the trabecular structure of human vertebral specimens and compared these techniques with measurement of bone mineral density (BMD) by using quantitative computed tomography to predict bone strength.

METHODS

Direct magnification radiographs and BMD measurements were obtained from 38 motion segments from the thoracolumbar spines of 11 female human cadavers. Maximum compressive strength (MCS) was determined with a materials testing machine. Morphologic parameters, digital skeletons, and fractal dimension were obtained from the radiographs in three different regions of interest.

RESULTS

Correlations between BMD and MCS were statistically significant (r = .81, P < .01). With morphologic parameters, correlation coefficients of up to .64 (P < .01) were obtained. Use of multivariate regression analysis with one morphologic parameter (the width of the black pixels, or thicknessB) in addition to BMD improved correlations versus MCS (P < .01).

CONCLUSION

In an experimental setting, BMD showed statistically significant correlation with bone strength, whereas the structural parameters demonstrated only modest correlations. BMD together with one of these measures (thicknessB), however, showed the highest correlation.

High resolution magnetic resonance imaging of the calcaneus: age-related changes in trabecular structure and comparison with dual X-ray absorptiometry measurements

A high-resolution magnetic resonance imaging (MRI) protocol, together with specialized image processing techniques, was applied to the quantitative measurement of age-related changes in calcaneal trabecular structure. The reproducibility of the technique was assessed and the annual rates of change for several trabecular structure parameters were measured. The MR-derived trabecular parameters were compared with calcaneal bone mineral density (BMD), measured by dual X-ray absorptiometry (DXA) in the same subjects. Sagittal MR images were acquired at 1.5 T in 23 healthy women (mean age: 49.3 +/- 16.6 [SD]), using a three-dimensional gradient echo sequence. Image analysis procedures included internal gray-scale calibration, bone and marrow segmentation, and run-length methods. Three trabecular structure parameters, apparent bone volume (ABV/TV), intercept thickness (I.Th), and intercept separation (I.Sp) were calculated from the MR images. The short- and long-term precision errors (mean %CV) of these measured parameters were in the ranges 1-2% and 3-6%, respectively. Linear regression of the trabecular structure parameters vs. age showed significant correlation: ABV/TV (r2 = 33.7%, P < 0.0037), I.Th (r2 = 26.6%, P < 0.0118), I.Sp (r2 = 28.9%, P < 0.0081). These trends with age were also expressed as annual rates of change: ABV/TV (-0.52%/year), I.Th (-0.33%/year), and I.Sp (0.59%/year). Linear regression analysis also showed significant correlation between the MR-derived trabecular structure parameters and calcaneal BMD values. Although a larger group of subjects is needed to better define the age-related changes in trabecular structure parameters and their relation to BMD, these preliminary results demonstrate that high-resolution MRI may potentially be useful for the quantitative assessment of trabecular structure.

Effects of propranolol on beta-adrenergic receptor of experimental acute myocardial infarction in rats

By using receptor autoradiography to observe the distribution and density of receptors, the effects of propranolol, a beta-blocker, on beta-adrenergic receptor of experimental acute myocardial infarction (AMI) were studied. One week after ligation of proximate left anterior descend (LAD) coronary artery, [3H] DHA binding sites were markedly decreased in both infarct region and non-infarct region. After treatment of propranolol (100 micrograms/kg), the [3H] DHA binding sites were obviously increased in the infarct region, and they were further decreased in the non-infarct region. The ratio of [3H] DHA binding sites of the infarct region to non-infarct region was from 0.24 at LAD ligation to 0.87 after propranolol treatment, which was close to 0.97 of control group (sham operation). The results indicated that the propranolol acted directly on myocardial beta- adrenergic through the receptor regulation of the balance of beta-receptors between the infarct region and non-infarct region, and improvement of the myocardial consonation and contraction synergism, thereby protecting the heart affected by AMI.

Human cancer cells exhibit protein kinase C-dependent c-erbB-2 transmodulation that correlates with phosphatase sensitivity and kinase activity

The c-erbB-2 receptor tyrosine kinase is often overexpressed in human tumors, but the functional implications of this phenotype remain unclear. We previously used phosphorylation-specific antibodies to define major differences in c-erbB-2 tyrosine kinase activity between overexpressing human tumor cell lines (Epstein, R. J., Druker, B. J., Roberts, T. M., and Stiles, C. D. (1992) Proc. Natl. Acad. Sci. U. S. A. 89, 10435-10439). Here we extend this approach to define the relationship between c-erbB-2 tyrosine phosphorylation and protein kinase C (PKC)-dependent transmodulation. Phosphorylation-specific antibodies to the juxtamembrane PKC site Thr686 recognize tyrosine-dephosphorylated wild-type c-erbB-2 following G8/DHFR 3T3 cell treatment with PKC agonists. B104-1-1 cells transformed by activated c-erbB-2 express a subset of tyrosine-phosphorylated receptors that are homologously phosphorylated on Thr686, indicating that Thr686 phosphorylation alone is insufficient to abrogate receptor tyrosine phosphorylation. Similarly, the c-erbB-2-overexpressing human cancer cell lines SK-Ov-3 and BT-474 express constitutively Thr686-phosphorylated receptors. SK-Ov-3 cells express predominantly kinase-inactive c-erbB-2 that is heavily Thr686-phosphorylated, indicating that Thr686 phosphorylation in this line is heterologous in origin. In contrast, BT-474 cells express constitutively autophosphorylated c-erbB-2 despite Thr686 phosphorylation. These results indicate that Thr686 phosphorylation does not directly abolish c-erbB-2 activity and suggest that such phosphorylation reflects constitutive PKC activity induced by either receptor-activating mutations or heterologous growth factors. The latter possibility suggests in turn that c-erbB-2 interacts in an as yet undefined way with heterologous growth factor receptors in human tumor cells.

Synthesis, radiosynthesis, and biological evaluation of fluorinated thienylcyclohexyl piperidine derivatives as potential radiotracers for the NMDA receptor-linked calcium ionophore

Various thienylcyclohexyl piperidine (TCP) derivatives were synthesized and evaluated as potential candidates for use as radiotracers for the in vivo study of the NMDA receptor ion-channel. Modification of the thienylcyclohexylpiperidine was accomplished by substituting its piperidine ring either with other cycloamine rings or N-alkyl-substituted amines, and these two classes of TCP derivatives were synthesized using two different methods. The compounds exhibited affinities ranging from 65 nM up to micromolar in competition assays for the receptor ion-channel labeled with 3H-(+)-MK-801 in rat brain homogenates. Radiosynthesis of 1-[1-(2-thienyl)-4-([18F]fluoro)-cyclohexyl]-1,2,5, 6-tetrahydropyridine was carried out by nucleophilic substitution reaction of 1-[1-(2-thienyl)-4-tosyloxycyclohexyl]-1,2,5,6-tetrahydropyridine with no carrier added 18F-, and the yield was approximately 5-10% (decay corrected) in specific activities of 500-1000 Ci/mmol after reverse-phase HPLC purification. The tracer showed good uptake in rat brains after i.v. injection (approx. 0.10% injected dose/g at 30 min. p.i.). However, the specific uptake in receptor-rich regions (striata, hippocampus, frontal cortex, and parietal cortex) improved only marginally with time compared to cerebellum. Three hours postinjection, parietal cortex showed a maximum ratio of 1.9. Preliminary PET experiment with this radiotracer in a rhesus monkey showed good uptake in the brain regions. However, little retention of the radiotracer was observed in the receptor-rich regions.

[Analysis of beta-thalassemia mutations and prenated diagnosis in Chengdu population]

Ninety-five of non-differential diagnostic patients were detected by dot-blot analysis on enzymatically amplified DNA with a number of allele specific oligonucleotide probes complementary to the most common mutations in Chengdu population. Prenatal diagnosis was accomplished by the same procedure on enzymatically amplified amniocyte DNA. The result revealed fifty-eight cases of beta-thalassemia. Of the 73 chromosomes tested, twenty-eight (38.4%) had the codon 17(A-->T) mutation, twenty-one (28.8%) had the codon 41-42(-TTCT) mutation, fourteen (19.0%) had the IVS-I-654(C-->T) mutation; nt--28(A-->G) and nt--29(A-->G) mutations were six (8.2%) and four (5.5%) respectively.

A single amino acid substitution in the capsid protein VP1 of coxsackievirus B3 (CVB3) alters plaque phenotype in Vero cells but not cardiovirulence in a mouse model

We previously described a large plaque attenuant (p14V-1) derived from a cardiovirulent Coxsackievirus B3 (CVB3) and showed that there were no major determinants of either attenuation or plaque phenotype in the 5' nontranslated region (5'NTR). Part of the region encoding the last 124 amino acids of VP3 and the first 106 amino acids of VP1 of the attenuant was then sequenced and compared to the wild-type. Three nucleotide changes were found in the VP1 coding region: a silent single base change at nucleotide position 2467 (C to U) and a double-base change at position 2690-1 (AA to GT), which leads to a change from lysine to serine at amino acid position 80. This mutation maps to the begining of B-C loop of the three-dimensional structure of VP1 of CVB3, where a distinct surface projection is formed. Two infectious chimeric cDNA clones were constructed, based on a cardiovirulent cDNA construct. In one construct, the 5'NTR and the VP3-VP1 region were from p14V-1 and in the other, only the VP3-VP1 region was from this attenuant. Both chimeric viruses produced large plaques on Vero cell monolayers, similar to p14V-1 but larger than the prototypic cardiovirulent virus. In vivo experiments showed that both chimeric viruses induced myocarditis in a murine model, similar to wild-type virus. We conclude that mutation serine-80 in capsid protein VP1 of p14V-1 is a determinant of the large plaque phenotype but is not responsible for attenuation.

Characterization of a murine model of myocarditis induced by a reactivated coxsackievirus B3

A transfection-reactivated Coxsackievirus B3 (rCVB3), from a full-length cDNA clone of Nancy strain, has previously been shown to be as cardiovirulent as the wild-type virus. Myocarditis induced by this genetically defined virus was compared in SWR mice with the traditional Balb/c model. SWR mice inoculated with rCVB3 developed more severe myocarditis but less severe pancreatitis than Balb/c mice. In contrast to the poor general health and frequent mortality of Balb/c mice following CVB3 infection, the body weight of SWR mice was not affected by CVB3 inoculation and no mortality occurred at titres of 10(2)-10(7) plaque forming units (PFU). Typical myocarditis developed in SWR mice 7 days post infection. Myocarditic foci consisting of necrotic myocardial fibres and mononuclear cell infiltrates resolved by day 30, similar to that observed in Balb/c. However, SWR mice were more sensitive to rCVB3-induced myocarditis than were Balb/c mice: mild myocarditis was induced (4/4) by as low as 10(2) PFU of the virus (ID50 < 10(1.5) PFU), and more severe myocarditis was seen at higher PFU of virus in a dose-dependent manner. The SWR model was tested with attenuated variants derived from cardiovirulent rCVB3. The ID50 for myocarditis was 10(7) PFU for a large plaque-size attenuant and 10(6) PFU for a minute plaque-size attenuant, indicating loss of cardiovirulence by a factor of more than 10(4)-10(5). rCVB3-induced SWR mouse is a sensitive and reliable model for myocarditis. It is useful in assessing the cardiovirulence of different CVB3 variants and evaluating the efficacies of anti-viral therapies. It will allow follow-up study after high dose infection with cardiovirulent rCVB3.

Incorporation of correlated structural images in PET image reconstruction

Reports on a new method in which spatially correlated magnetic resonance (MR) or X-ray computed tomography (CT) images are employed as a source of prior information in the Bayesian reconstruction of positron emission tomography (PET) images. This new method incorporates the correlated structural images as anatomic templates which can be used for extracting information about boundaries that separate regions exhibiting different tissue characteristics. In order to avoid the possible introduction of artifacts caused by discrepancies between functional and anatomic boundaries, the authors propose a new method called the "weighted line site" method, in which a prior structural image is employed in a modified updating scheme for the boundary variable used in the iterative Bayesian reconstruction. This modified scheme is based on the joint probability of structural and functional boundaries. As to the structural information provided by CT or MR images, only those which have high joint probability with the corresponding PET data are used; whereas other boundary information that is not supported by the PET image is suppressed. The new method has been validated by computer simulation and phantom studies. The results of these validation studies indicate that this new method offers significant improvements in image quality when compared to other reconstruction algorithms, including the filtered backprojection method and the maximum likelihood approach, as well as the Bayesian method without the use of the prior boundary information.

Selection of spectral lines for combustion diagnostics

This paper reports part of our effort to develop practical systematic techniques for measurements in high temperature gases using laser absorption spectroscopy. We present a brief summary of the analysis techniques we have developed for line-of-sight measurements. We show that the accuracy of the absorption measurement in a given experiment is largely determined by the spectral lines used for the measurement. Thus the selection of spectral lines is critical for the success of a diagnostic measurement. In this paper, we propose a set of criteria for selecting spectral transitions for temperature and concentration measurements at various experimental conditions. They include the requirements for spectral line resolution, absorption strength, sensitivity, and insensitivity to systematic errors. These rules could be implemented in an expert system. A simplified version of the selection criteria was implemented in a PASCAL program. The capabilities of the program are demonstrated by the selection of absorption transitions of CO for simultaneous temperature and species concentration measurements at several experimental conditions. The criteria and program may be readily extended to other spectroscopic techniques such as laser-induced fluorescence.

Line-of-sight absorption measurements of high temperature gases with thermal and concentration boundary layers

The effect of thermal and concentration boundary layers on experimental data must be well understood for a successful diagnostic measurement of quasi-uniform high-temperature gases using line-of-sight absorption spectroscopy. In this paper, an energy-temperature curve is proposed to assist in selection of candidate absorption lines. Two techniques, the effective absorption path length method and the direct curve-fit method, are proposed to extract absolute concentrations from absorption data obtained in the presence of boundary layers.

Reliable and efficient program for fitting Galatry and Voigt profiles to spectral data on multiple lines

Experimental data with multiple overlapping spectral lines must often be fitted to theoretical line shape models. This paper describes an efficient program for performing least-squares fits of such data to Galatry and Voigt profiles. The algorithm and program design considerations are presented in detail, and some examples are given to demonstrate its use. The procedure described in this paper may also be used for more complex line shape profiles.