[Effect of ginseng injection in treating congestive heart failure and its influence on thyroid hormones]

OBJECTIVE

To observe the effect of Ginseng injection on congestive heart failure (CHF) and its influence on thyroid hormones.

METHODS

Fifty-four Patients of CHF were divided into two groups. On the basis of conventional treatment of western medicine, the Ginseng injection was given to the treated group additionally. Blood level of triiodothyronine (T3), thyroxine (T4), reverse triiodothyronine (rT3) and thyroid stimulating hormone (TSH) of all patients were determined before and after treatment by radioimmunoassay.

RESULTS

There were significant difference between the treated group and the control group in cure rate and mean course of therapy. The levels of T3 and T4 of all patients were lower than those of the normal control before treatment, and rT3 were higher. Two weeks after treatment, T3 and T4 level in all patients increased significantly and rT3 level significantly decreased(P < 0.05, P < 0.01).

CONCLUSION

Ginseng injection has a good effect on patients with CHF. It also has regulatory effect on thyroid hormones.

[Gene expression of beta-adrenoceptor signal transmitters in heart failure]

OBJECTIVE

To investigate the alteration in steady-state levels of messenger RNA(mRNA) of beta-adrenoceptor signal transmitters in heart failure.

METHODS

The reverse transcription polymerase chain reaction (RT-PCR) was used to assess gene expression in small quantity of circulatory lymphocytes. With selected oligonucleotide primers, we used quantitative RT-PCR to amplify mRNAs encoding beta 2-adrenergic receptor(beta 2-AR), adenylate cyclase (AC), beta 2-adrenergic receptor kinase(beta-ARK), and beta-arrestin and cAMP response element binding protein (CREB) in 16 healthy subjects and 30 heart-failing patients.

RESULTS

The alteration of gene expression in heart failure appeared to be selective, the steady-state levels of mRNA increased significantly involving AC and the transcription factor, CREB; decreased significantly involving membrane receptor, beta 2-AR; unchanged significantly involving phosphorylating factors of beta-AR uncoupling, beta-ARK and beta-arrestin.

CONCLUSION

The aberrant gene expression of beta-adrenergic receptor might play an important role in the pathogenesis of heart failure.

Ibogaine blocked methamphetamine-induced hyperthermia and induction of heat shock protein in mice

Body temperature changes and heat shock protein (HSP-72) induction in the caudate nucleus were studied in female C57BL/6N mice pretreated with ibogaine (50 mg/kg) and sacrificed 48 h. after a single dose of methamphetamine (20 mg/kg). Methamphetamine injection resulted in hyperthermia and induced HSP-72 expression, whereas treatment with ibogaine alone produced hypothermia. The ibogaine followed by methamphetamine injection showed no hyperthermia and decreased HSP-72 expression. These data indicate that pretreatment with ibogaine can completely block methamphetamine-induced hyperthermia and HSP-72 expression in the striatum.

Biochemical and electron microscopic image analysis of the hexameric E1 helicase

DNA replication initiator proteins bind site specifically to origin sites and in most cases participate in the early steps of unwinding the duplex. The papillomavirus preinitiation complex that assembles on the origin of replication is composed of proteins E1 and the activator protein E2. E2 is an ancillary factor that increases the affinity of E1 for the ori site through cooperative binding. Here we show that duplex DNA affects E1 (in the absence of E2) to assemble into an active hexameric structure. As a 10-base oligonucleotide can also induce this oligomerization, it seems likely that DNA binding allosterically induces a conformation that enhances hexamers. E1 assembles as a bi-lobed, presumably double hexameric structure on duplex DNA and can initiate bi-directional unwinding from an ori site. The DNA takes an apparent straight path through the double hexamers. Image analysis of E1 hexameric rings shows that the structures are heterogeneous and have either a 6- or 3-fold symmetry. The rings are about 40-50 A thick and 125 A in diameter. The density of the central cavity appears to be a variable and we speculate that a plugged center may represent a conformational flexibility of a subdomain of the monomer, to date unreported for other hexameric helicases.

Interstitial brachytherapy using iridium-192 for malignant brain tumors: clinical results

OBJECTIVE

To determine the effects and toxicity of interstitial brachytherapy using iridium-192 on brain malignant gliomas.

METHODS

Between January 1992 and January 1995, 56 patients with anaplastic astrocytoma and glioblastoma multiforme were treated with stereotactic brachytherapy using temporary high-activity iridium-192 sources.

RESULTS

The median survival for patients receiving brachytherapy was 28 months. The survival rates at 1, 2, 3 years were 92.8%, 83.9% and 71.4% respectively.

CONCLUSIONS

Brachytherapy may improve the control of local tumor and prolong the survival, when used in deep malignant brain gliomas, by temporary implanted high doses of iridium-192 sources.

Identification of in vitro metabolites of Indinavir by "intelligent automated LC-MS/MS" (INTAMS) utilizing triple quadrupole tandem mass spectrometry

In an effort to improve the efficiency of the TSQ 7000 LC-MS/MS system for identification of drug metabolites in biological matrices in support of drug discovery programs, a combination of instrument control language procedures for the Finnigan MAT TSQ 7000 mass spectrometer, referred to as INTAMS, were composed. INTAMS was designed to conduct unattended, automatic liquid chromatography/mass spectrometry (LC-MS) and LC-MS/MS analyses of drugs and metabolites in commonly encountered in vitro biological matrices. A novel peak detection algorithm was developed to automatically detect and record the pseudomolecular ions and retention times of chromatographic components, even if not fully resolved. This algorithm was used in combination with an automated technique for predicting the molecular weights of metabolites based on incremental changes of the molecular weight of the parent drug resulting from well-known biotransformation processes. When applied to a sample of an incubation mixture of the HIV protease inhibitor Indinavir with a rat liver S9 preparation, the results obtained by the automatic metabolite detection procedures for LC-MS and LC-MS/MS analyses in real time were the same as those which were determined manually, by a knowledgeable operator.

Visualization of protein-RNA interactions in cytoplasmic polyhedrosis virus

Unlike the multiple-shelled organization of other Reoviridae members, cytoplasmic polyhedrosis virus (CPV) has a single-shelled capsid. The three-dimensional structures of full and empty CPV by electron cryomicroscopy show identical outer shells but differ inside. The outer surface reveals a T=1 icosahedral shell decorated with spikes at its icosahedral vertices. The internal space of the empty CPV is unoccupied except for 12 mushroom-shaped densities attributed to the transcriptional enzyme complexes. The ordered double-stranded RNA inside the full capsid forms spherical shells spaced 25 A apart. The RNA-protein interactions suggest a mechanism for RNA transcription and release.

[Effects of humic acid on lipid peroxidation in arsenosis prevalent areas]

OBJECTIVE

To explore the causes of blackfoot disease in Taiwan.

METHODS

Experiments to induce lipid peroxidation by arsenic and humic acid were made in vitro. Arsenic was determined for the water sampled from the arsenosis prevalent areas in Inner Mongolia and blackfoot disease prevalent areas in Taiwan and humic acid determined for the extracts of the coal rich in arsenic sampled from Guizhou Province in China by MDA-TBA colorimetry.

RESULTS

Experiments found that humic acid could induce lipid peroxidation caused by sodium salt of unsaturated fatty acids in vitro in a weak and unstable manner, which could be promoted by 0.05 mmol/L of Fe(+ +) and not by 1 mmol/L As(2)O(3). The extent of lipid peroxidation caused depended on the sources, constituents and structure of humic acid samples, those from Inner Mongolia ranked the highest, those from Guizhou and Taiwan the medium and the commercial humic acid (Aldrich Co. in the US) the lowest. The experiments also found that lipid peroxidation caused by commercial humic acid presented a dynamic process in the existence of trace amount of iron, and humic acid could decompose the products of lipid peroxidation.

CONCLUSION

The experiments suggested the relations of humic acid and arsenic to iron and other transition elements in the blackfoot disease prevalent areas and areas with an environment rich in arsenic and humic acid.

Expression of a foreign protein in human megakaryocytes and platelets by retrovirally mediated gene transfer

Recent progress in the culture of human megakaryocytes (MKs) has led to the capacity to produce platelets in vitro. This capability enables investigation into the possibility of modifying platelet structure and/or function by genetically altering the MK. To this end, a cDNA for the murine CD9 (mCD9) cell surface protein was introduced into MK progenitors by retrovirally mediated gene transfer and subsequently detected in cultured MKs with a monoclonal antibody (MoAb) that specifically recognizes the murine protein. CD34+ human peripheral blood or marrow progenitors, enriched by immunomagnetic bead selection, were cultured for 5 days in the presence of growth factors, including stem cell factor and thrombopoietin, to induce MK progenitors into the cell cycle. The stimulated cells were then cocultured with the mCD9 retroviral producer cell line for 3 days, followed by culture in serum-depleted medium for 3 to 7 additional days. Flow cytometry analysis using the anti-CD9 MoAb and TAB, a MoAb recognizing human GPIIb, revealed that a large proportion (40-100%) of the MKs expressed mCD9. To ascertain whether these cells were capable of producing mCD9+ platelets, flow cytometry analysis was performed at a time when proplatelets were observed in the culture. mCD9 was detected in up to 59% of the TAB+ platelet-sized particles. Because deteriorating MKs can produce platelet-sized particles in vitro, experiments were performed to determine whether mCD9+ TAB+ particles were functionally active. Addition of phorbol myristate acetate resulted in the redistribution of P-selectin (CD62) from the alpha granule to the platelet surface as detected by MoAbs S12 and G5 in three-color flow cytometry analyses. These studies showed that up to 76% of the mCD9+ TAB+ particles were functionally active. The data show that retrovirally mediated gene transfer is a viable approach for genetically altering MK progenitors, resulting in platelets that express heterologous proteins.

[Studies on immune responses in mice to expressed products from CSP gene of Plasmodium falciparum FCC1/HN isolate]

AIM

To construct the eukaryotic expression system with pcDNA3-PfCSP/HeLa for CSP gene of Plasmodium falciparum, and to observe the immune responses in BALB/c mice induced by the expressed proteins.

METHODS

The recombinant plasmid pcDNA3-PfCSP was transformed into mammalian cell line of human HeLa cells. The expressed protein was isolated and analyzed by SDS-PAGE and used for immunization of BALB/c mice by subcutaneous, intravenous or intraperitoneal administration, respectively. ELISA, Western blotting, T lymphocyte proliferation test, natural killer cell activity and CD4+ and CD8+ T cells detection were used for observation of the level of humoral and cellular immune responses.

RESULTS

Immune sera strongly reacted with the expressed protein. The titer of the antibodies was up to 1:6,400 by ELISA. Western blotting analysis revealed a specific band at 38.3 kDa. The specific proliferative response with immunized BALB/c mice spleen cells was remarkablely higher than that with control ones. The ratio of CD4+ and CD8+ T cells and the NK cell activity were significantly higher in the immunization group than that in the control groups.

CONCLUSION

The humoral and cell-mediated immune responses and elevated NKC activity to expressed products with the eukaryotic expression system can specifically be detected in BALB/c mice to generate, indicating that the expressed protein could enhance immune activity in mice.

Neural network decision directed edge-adaptive Kalman filter for image estimation

A neural network-based scheme for decision directed edge-adaptive Kalman filtering is introduced in this work. A backpropagation neural network makes the decisions about the orientation of the edges based on the information in a window centered at the current pixel being processed. Then based upon the neural network output an appropriate image model which closely matches the local statistics of the image is chosen for the Kalman filter. This prevents the oversmoothing of the edges, which would have otherwise been caused by the standard Kalman filter. Simulation results are presented which show the effectiveness of the proposed scheme.

[The value of electronystagmography in differential diagnosis of vertigo]

Findings of electronystagmography (ENG) in 645 patients with vertigo were analysed. Two hundred and twelve cases showed vestibular peripheral vertigo, 394 cases vestibular central vestigo, and 39 cases other types of vertigo. The ENGs in patients with vestibular peripheral vertigo were charazterized mainly by the vestibular abnormal caloric responses, spontaneous and benign positional nystagmuses were also obsedrved at the same time. Different degrees and various combinations of the abnormal responses shown in optokinetic central test were the most characteristic of ENG in patients with vestibular central vertigo. The results suggest that ENG is particularly useful for differentiating peripheral and central vertigo.

Nitric oxide and N-acetylcysteine inhibit the activation of mitogen-activated protein kinases by angiotensin II in rat cardiac fibroblasts

Angiotensin II acts on the cardiac fibroblast to produce a mitogenic response. Nitric oxide and N-acetylcysteine have been used to determine if oxidative stress influenced the effects of angiotensin II on the cardiac fibroblast. Angiotensin II activated the mitogen-activated protein kinases designated extracellular signal-regulated kinases within 5 min by interacting with the AT1 receptor. This activation was completely independent of protein kinase C and was inhibited when farnesylation was blocked, implicating Ras involvement. Pretreatment of cardiac fibroblasts with either N-acetylcysteine for 8 h or nitric oxide for 10 min suppressed this activation by angiotensin II in a dose-dependent manner. However, when both agents were added, inhibition was essentially complete. This combined effect of N-acetylcysteine and nitric oxide to block ERKs activation also was found if the activity was stimulated by either another growth factor (platelet-derived growth factor) or by the addition of phorbol ester, suggesting the effect was not limited to the receptor site alone. The results are consistent with the hypothesis that hormonal activation of mitogenic steps such as ERKs is influenced by increased oxidative stress, which is reduced by the combined effects of N-acetylcysteine and nitric oxide.

Transcriptional repression due to high levels of Wingless signalling

Extracellular signals can act at different threshold levels to elicit distinct transcriptional and cellular responses. Here, we examine the transcriptional regulation of the Wingless target gene Ultrabithorax (Ubx) in the embryonic midgut of Drosophila. Our previous work showed that Ubx transcription is stimulated in this tissue by Dpp and by low levels of Wingless signalling. We now find that high levels of Wingless signalling can repress Ubx transcription. The response sequence within the Ubx midgut enhancer required for this repression coincides with a motif required for transcriptional stimulation of Dpp, namely a tandem of binding sites for the Dpp-transducing protein, Mad. Indeed, Wingless-mediated repression depends on low levels of Dpp, although apparently not on Mad itself. In contrast, high levels of Dpp signalling antagonize Wingless-mediated repression. This suggests that transcriptional activation of Ubx is subject to competition between Dpp-activated Mad and another Smad whose function as a transcriptional repressor depends on high Wg signalling. Finally, we show that Wingless can repress its own expression via an autorepressive feedback loop that results in a change of the Wingless signalling profile during development.

A clinical trial of tang shen ning for treatment of diabetic nephropathy

This paper reports the clinical trial of Tang Shen Ning ([symbol: see text], TSN) for treating diabetic nephropathy (incipient and clinical, as divided by Mogensen). The results showed that the total effective rate in treatment group (TSN + western medicine) was 90.0%, and that in the control group (simply with western medicine), 56.7%. TSN plays important roles in decreasing proteinuria and improving renal functions.

Identification of a defined epitope on the surface of the active RecA-DNA filament using a monoclonal antibody and three-dimensional reconstruction

Studies of the Escherichia coli RecA protein are expected to illuminate mechanisms of DNA recombination and repair in bacteria, and in all higher organisms as well, due to the functional and structural homology with the eukaryotic Rad51 protein. The active form of the RecA protein is a helical filament formed on DNA in the presence of ATP or ATP analogs, and this has been studied at low-resolution by electron microscopy. An atomic model of the protein comes from an X-ray crystallographic study of a filament formed in the absence of DNA and ATP. This filament is believed to be an inactive, storage form of the protein. A key step in generating an atomic model of the active filament, and a detailed model for function, is to understand the large conformational changes that occur between these two states. Towards this end, we have decorated active RecA-DNA filaments with monoclonal antibodies (ARM191) against a known epitope (residues 285 to 320) to determine the position of this epitope in the low-resolution structure. Electron microscopy and three-dimensional reconstruction of the RecA-antibody complex reveal that the lobe containing the epitope is very disordered on the surface of the filament, but in a position similar to that in the inactive crystal filament. The antibody binding also induces a significant conformational change in the RecA filament. This study shows that the basic orientation of the subunit is likely to be similar within the inactive and active filaments, and that the large movement of mass that occurs between these two states must involve other residues than the 285-320 region.

The influence of physical structure and charge on neurite extension in a 3D hydrogel scaffold

Understanding neural cell differentiation and neurite extension in three-dimensional scaffolds is critical for neural tissue engineering. This study explores the structure-function relationship between a 3D hydrogel scaffold and neural cell process extension and examines the role of ambient charge on neurite extension in 3D scaffolds. A range of agarose hydrogel concentrations was used to generate varied gel physical structures and the corresponding neurite extension was examined. Agarose gel concentration and the corresponding pore radius are important physical properties that influence neural cell function. The average pore radii of the gels were determined while the gel was in the hydrated state and in two different dehydrated states. As the gel concentration was increased, the average pore radius decreased exponentially. Similarly, the length of neurites extended by E9 chick DRGs cultured in agarose gels depends on gel concentration. The polycationic polysaccharide chitosan and the polyanionic polysaccharide alginate were used to incorporate charge into the 3D hydrogel scaffold, and neural cell response to charge was studied. Chitosan and alginate were covalently bound to the agarose hydrogel backbone using the bi-functional coupling agent 1,1'-carbonyldiimidazole. DRGs cultured in chitosan-coupled agarose gel exhibited a significant increase in neurite length compared to the unmodified agarose control. Conversely, the alginate-coupled agarose gels significantly inhibited neurite extension. This study demonstrates a strong, correlation between the ability of sensory ganglia to extend neurites in 3D gels and the hydrogel pore radius. In addition, our results demonstrate that charged biopolymers influence neurite extension in a polarity dependent manner.

The restraint stress-induced elevation in plasma interleukin-6 negatively regulates the plasma TNF-alpha level

Although a considerable amount of evidence has shown that physical and psychological stress elevates the plasma interleukin 6 (IL-6) levels, the physiological significance of such an elevation remains to be elucidated. In this study, in order to determine whether the restraint stress-induced elevation of plasma IL-6 contributes to the activation of the hypothalamic-pituitary-adrenal axis, and whether or not such elevation can affect the inflammatory processes, the plasma levels of ACTH, corticosterone, interleukin-1 (IL-1), and tumor necrosis factor-alpha (TNF-alpha) in mice pretreated with anti-IL-6 antibody (MP5-20F3 monoclonal antibody) were compared with those in mice pretreated with rat IgG (control antibody) both during and after stress. Both the anti-IL-6-antibody- and control-antibody-pretreated mice showed the same extent of plasma ACTH and corticosterone increases during stress, and no significant difference was found between the two groups of animals. On the other hand, the level of plasma TNF-alpha in the anti-IL-6-treated animals was also significantly higher than that in the control animals both immediately after cessation of stress and 60 min after the cessation of the 120-min period of restraint. Plasma IL-1 activity, however, did not reach a detectable level in either group of animals at any time point examined. These results thus indicate that the restraint-stress-induced elevation of plasma IL-6 negatively regulates the plasma TNF-alpha levels and may thus contribute to the maintenance of homeostasis.

[Cellular sociological characteristics of osteoblasts]

There is a great hope to treat long bone defects with bioactive artificial bone constructed by osteoblasts and biomaterials, in which the key point is to provide an optimum environment for the normal function of osteoblasts. The cellular sociological characteristics of osteoblasts were summarized and it was suggested that the ideal bioactive artificial bone should be composed of inorganic and organic materials together with cellular components such as osteoblasts and vascular endothelial cells, and combined with control release of growth factors, following its implantation it could be vascularized very soon and merged with the host bone by bony consolidation.

RFLP mapping and race specificity of bacterial blight resistance genes (QTLs) in rice

By using a set of 315 recombinant inbred lines (RILs) from the cross Lemont (japonica) x Teqing (indica) and a complete linkage map with 186 well distributed RFLP markers and 3 morphological markers, a major gene (Xa4) and 10 QTLs and 9 pairs of epistasis loci conferring horizontal resistance to three strains of Xanthomonas oryxa pv oryza (Xoo) were mapped. The Teqing allele at Xa4 on chromosome 11 acts as a dominant resistant gene against pathogen race CR4 and CX08, but as an additive QTL with a significantly (47%) reduced effect against the virulent strain, CR6. The major gene Xa4 exhibited stronger degree of race specificity. Most QTLs showed consistent levels of resistance against all three Xoo strains. The results suggest that a high level durable resistance to Xoo may be achieved by cumulative effects of multiple QTL.

[Pathologic changes of palatopharyngeal soft tissue in obstructive sleep apnea syndrome]

OBJECTIVE

To study the pathologic changes of palatopharyngeal soft tissues in patients with OSAS.

METHODS

Different analyses have been done on uvular muscles (UM) and/or palatopharyngeal muscles (PPM) in patients with OSAS(n = 27), SS(n = 17) and controls (n = 15). The transverse sections were sequentially stained for HE, myofibrillar ATPase, NADH-TR, Lillie Oil Red-O. Ten specimens were evaluated by transmission electron microscopy(TEM).

RESULTS

Patients with OSAS have a significantly smaller percentage of muscle in the uvula than that of SS patients (15.0 +/- 3.0 vs 20.3 +/- 5.5), The percentage of muscle is inversely related to the percentage of fibrous tissue in OSAS group (r = -0.75, Y = 42.6 - 0.64X); The total number and area of muscle fibers, the number and area of type I muscle fibers are significantly lower in OSAS than those in SS (800 +/- 345 vs 1200 +/- 360n; 1.10 +/- 0.56 vs 1.70 +/- 0.60 micron 2; 156 +/- 95 vs 360 +/- 225 n; 920 +/- 350 vs 1365 +/- 540 micron 2 respectively); PPM: The percentage of type I muscle fibers within total muscles and its area are significantly lower in OSAS than those in SS and normal controls(20.5 +/- 4.0 vs 34.5 +/- 4.5 n; 20.5 +/- 4.0 vs 35.5 +/- 4.7; 860 +/- 360 vs 1260 +/- 340 micron 2; 860 +/- 360 vs 1350 +/- 370 micron 2; respectively); the muscles from OSAS patients seemed to show neurogenic alterations. Structurally altered fibers shows myofibrillar loss, increased number of vesicles, and rough Z line and so on.

CONCLUSION

Our finding suggest that the neurogenic functional disturbance of pharyngeal dilator muscles may play an important role in causing the airway collapse in OSAS.

The C-terminal (BRCT) domains of BRCA1 interact in vivo with CtIP, a protein implicated in the CtBP pathway of transcriptional repression

The BRCA1 tumor suppressor encodes a polypeptide with two recognizable protein motifs: a RING domain near the N terminus and two tandem BRCT domains at the C terminus. Studies of tumor-associated mutations indicate that the RING and BRCT sequences are required for BRCA1-mediated tumor suppression. In addition, recent work has shown that BRCA1 is a potent regulator of RNA transcription and that the BRCT domains are also essential for this activity. Therefore, we used the Sos recruitment system to screen for proteins that bind this critical region of BRCA1. Our results show that the BRCT domains interact in vivo with CtIP, a protein originally identified on the basis of its association with the CtBP transcriptional co-repressor. This finding suggests that BRCA1 regulates gene expression, at least in part, by modulating CtBP-mediated transcriptional repression. Moreover, the in vivo interaction between BRCA1 and CtIP is completely ablated by each of three independent tumor-associated mutations affecting the BRCT motifs of BRCA1. These results indicate that the BRCA1-CtIP interaction may be required for tumor suppression by BRCA1.

Linear and cyclic peptides as substrates and modulators of P-glycoprotein: peptide binding and effects on drug transport and accumulation

One cause of multidrug resistance (MDR) in human cancers is the overexpression of the P-glycoprotein multidrug transporter, a member of the ABC superfamily of membrane proteins. Natural products and chemotherapeutic drugs are pumped out of the cell by P-glycoprotein in an ATP-dependent fashion. There is growing evidence that many hydrophobic peptides are also P-glycoprotein substrates. With the use of a fluorescence-quenching assay, we have shown that some linear and cyclic hydrophobic peptides interact with P-glycoprotein, whereas others do not. The measured values of the quenching constant, Kq, for interaction of peptides with P-glycoprotein ranged from 200 nM for cyclosporine A to 138 microM for the tripeptide N-acetyl-leucyl-leucyl-norleucinal. Peptides that interacted with P-glycoprotein in the fluorescence assay also blocked colchicine transport into plasma membrane vesicles from MDR cells. The values of Dm, the peptide concentration causing 50% inhibition of drug uptake, were highly correlated with the values of Kq, over three orders of magnitude. The P-glycoprotein ATPase stimulation/inhibition profile of the peptides was not helpful in making a quantitative assessment of the ability of a peptide to interact with P-glycoprotein or to block drug transport. Some hydrophobic peptides were able to restore accumulation in MDR cells of the chemotherapeutic drug daunorubicin and the fluorescent dye rhodamine 123 to the levels observed in the drug-sensitive parent. Peptides that interacted with P-glycoprotein also displayed a relatively low overall toxicity to intact MDR cells, and inhibited drug transport at concentrations below the toxic range. Hydrophobic peptides should be given serious consideration for development as clinical chemosensitizing agents.

[The development of JX-300 high quality head stereotactic guided surgical system]

Based on the technology of three dimensions image forming and the arc stereotactic guided operator, this system has the advantages of locating precisely, convenient operation, and good result of curing. It has the imitation checking system of operation to guarantee the safe of patients.

Expression of a defense-related 3-hydroxy-3-methylglutaryl CoA reductase gene in response to parasitization by Orobanche spp

Orobanche spp. are angiosperms that live parasitically on the roots of other plants, and are capable of significantly reducing the yield and quality of their crop hosts. We have demonstrated that parasitization by Orobanche induces expression of hmg2, a defense-related isogene of 3-hydroxy-3-methylglutaryl CoA reductase (HMGR) in tobacco. Transgenic tobacco plants expressing a construct containing 2.3 kb of the tomato hmg2 gene promoter fused to the beta-glucuronidase (GUS) reporter gene were parasitized by O. aegyptiaca. Expression of the hmg2:GUS construct was detected within 1 day following penetration of the host root by the O. aegyptiaca radicle and was localized to the region immediately around the site of parasite invasion. This expression continued and intensified over the course of O. aegyptiaca development. In addition, the hmg2:GUS expression was induced by secondary parasitization, where secondary roots of O. aegyptiaca contacted the host root at a distance from the primary attachment site. This GUS expression was specific to plants containing the hmg2:GUS construct, and was not observed in control plants transformed with a construct of the cauliflower mosaic virus 35S promoter fused to the GUS gene. These results indicate that Orobanche parasitization initiates rapid and sustained induction of a defense-related gene in the host root.

[The safety interlock designed for JX-100 X-knife system]

This paper describes the design of a safety interlock used by X-knife system for preventing the linear accelerator gantry colliding with the treatment couch and the patient when the accelerator is rotating and irradiating X-rays. How to install and adjust the unit is also addressed in this paper. The unit has been successfully used in JX-100 X-knife system developed by the First Military Medical University.

Assessing the relative contribution of molecular and morphological characters in simultaneous analysis trees

We examined the contribution of morphological and molecular character information for 15 systematics studies in which these two kinds of data were used in combined or simultaneous analyses. Assessment of the disagreement between these data sources, as measured by the incongruence length difference, reveals substantial conflict for the studies surveyed. In addition, the partitioned Bremer support was used to measure the degree of support provided by each data partition when analyzed together. Despite the significant incongruence found for nearly half the studies, the PBS indices suggest both types of data contribute positively to the combined analyses and that, when standardized by the number of phylogenetically informative characters, morphology data generally provide equal or greater support than do the molecular data. This result, combined with the fact that morphological characters generally exhibit higher consistency, indicates that this source of character information continues to be useful in systematics studies despite the increasing volume of available molecular data.

The role of B7-CD28 co-stimulation in tumor rejection

The role of B7 co-stimulatory signaling in in vivo tumor rejection remains incompletely characterized. In particular, the relative competence of B7-1 (CD80) and B7-2 (CD86) to provide effective co-stimulus is not well defined, and the identification of the T cell co-stimulatory receptor that mediates B7 co-stimulation in tumor rejection has not been addressed. These issues were studied by assessing rejection of B7-negative or B7-transfected tumor cells in CD28-expressing or CD28-deficient hosts. B7-negative EL4 tumor cells grew progressively in normal syngeneic C57BUL6 (B6) mice. In contrast EL4 cells transfected with either full length B7-1 or full length B7-2 were rejected, indicating that both B7-1 and B7-2 are competent to mediate rejection of EL4 tumor cells. Expression of truncated B7-1 or B7-2 products, with complete deletion of cytoplasmic domains, was as effective as expression of full length B7-1 or B7-2 in mediating rejection. In contrast to the rejection of B7-transfected EL4 cells observed in CD28-expressing syngeneic hosts, B7-1- and B7-2-positive EL4 cells as well as control EL4 cells grew progressively in CD28-deficient mice, demonstrating the requirement for host expression of CD28 in B7-mediated tumor rejection. These results indicate that interaction of host CD28 with co-stimulatory extracellular B7-1 or B7-2 ligands expressed on tumor cells can play a necessary role in mediating tumor rejection.

[The development of Model Cihang-2000 mini multi-function electrocardiograph]

The Model Cihang-2000 mini multi-function electrocardiograph is introduced in this paper. A lot of advanced electronic techniques and data processing techniques are used in this instrument. It is not only high in quality and small in size, but also strong in function.

CT-guided stereotactic biopsy of deep brain lesions: report of 310 cases

OBJECTIVE

To evaluate the accuracy of CT-guided stereotactic biopsy in making correct pathological diagnosis and choosing corresponding management of brain tumors.

METHODS

From 1991 to 1995, CT-guided stereotactic biopsy was performed in 310 patients with intracerebral lesions which were deep-seated or located in certain main functional areas. The patients were 198 men and 112 women. Their ages ranged from 4.5 to 70 years (average: 39.3 years). The lesions were located in the deep cerebrum (74 patients), the sellar area (62), the basal ganglion (51), the posterior part of the third ventricle (38), other intraventricleular area (21), the cerebellum (17) and the brain stem (9), and intracranial multiple lesions were found in 38 patients.

RESULTS

Brain tumors were diagnosed pathologically in 266 patients (85.8%); inflammatory process in 25 (8.1%), other lesions in 8 (2.6%) and uncertain cases were 11 (3.6%). The overall positive rate of biopsy was 96.4% and the positive rate for brain tumor was 85.8%. Intracranial hematomas after biopsy were found in 5 patients (1.6%). There were no deaths induced by the biopsy or other serious complications.

CONCLUSIONS

The results suggest that CT-guided stereotactic biopsy is a reliable method for histopathological diagnosis of brain tumors and it is also of great help in selecting appropriate management.

[Observations of changes in neurobehavioral functions in workers exposed to high-frequency radiation]

OBJECTIVE

To study the effects of exposure to high-frequency radiation on neurobehavioral function of the exposed workers and its measurement in evaluating occupational hazards caused by it.

METHODS

Four neurobehavioral functions were tested for the workers exposed to high-frequency radiation with Neurobehavioral Core Tests Battery recommended by WHO.

RESULTS

Scores for various indicators in exposed workers were significantly lower than those in controls, and correlated to the detection of neurasthenia in the exposed workers, to certain extent.

CONCLUSION

Changes in neurobehavioral function in workers exposed to high-frequency radiation can reflect its important adverse effects.

[Studies on mutagenicity of humic acid samples collected from arsenosis-affected areas in China]

OBJECTIVE

To explore whether there is mutagenicity of humic acid samples collected from arsenosis affected areas in China.

METHODS

Ames' test was used for natural humic acid samples extracted from the coal containing high arsenic in Guizhou Province, and the well water in the areas with blackfoot disease in Taiwan and with arsenosis in Inner Mongolia of China.

RESULTS

Coefficients of revertant mutation were 1.02-0.82 net revertant per microgram (rev/microgram) of humic acid extracted from the coal containing high arsenic in Guizhou without rat liver homogenate (-S9), and 1.53-1.12 rev/microgram of that with rat liver homogenate (+S9), with an obvious dose-response relationship.

CONCLUSION

Humic acid extracted from the coal containing high arsenic produced in Guizhou could cause stronger direct mutation in Salmonella typhimurium TA98 (frameshift mutation) and that extracted from the well water in the areas with blackfoot disease in Taiwan could cause weaker direct mutation in Salmonella typhimurium (-S9), but that extracted from the well water with arsenosis in Inner Mongolia could not cause mutation. Mutagenicity of commercial humic acid, purchased from Aldrich Co. in the United States, arsenic and iron was also studied, and no mutagenicity was found for them independently, but arsenic combined with humic acid, at certain concentrations, could cause weak mutation in TA98 (-S9), with or without iron. No mutagenicity in TA100 (+/- S9, base pair substitution mutation) was found in all the samples mentioned above.

Urinary 2,5-hexanedione increases with potentiation of neurotoxicity in chronic coexposure to n-hexane and methyl ethyl ketone

OBJECTIVE

MEK (methyl ethyl ketone) is widely and frequently used as an ingredient of mixed solvents together with n-hexane. MEK is known to decrease urinary levels of 2,5-hexanedione dose-dependently in an acute or chronic coexposure with a constant level of n-hexane. This change in urinary 2,5-hexanedione appears to contradict the potentiation effect of MEK on n-hexane-induced neurotoxicity because it is believed that the toxicity of n-hexane is activated through n-hexane metabolism. We aimed to clarify how the urinary level of 2,5-hexanedione changes when MEK modifies the degree of n-hexane-induced neurotoxicity.

METHOD

A total of 32 male Wistar rats were divided into 4 groups of 8 each and were then exposed to fresh air only, 2000 ppm n-hexane only, 2000 ppm n-hexane plus 200 ppm MEK, and 2000 ppm n-hexane plus 2000 ppm MEK, respectively. Inhalation exposures were performed 12 h/day, 6 days/week, for 20 weeks. Motornerve conduction velocity (MCV), distal latency (DL), and urinary 2,5-hexanedione were measured every 4 weeks.

RESULTS

The MCV decreased, the DL increased, and urinary levels of 2,5-hexanedione increased in the 2000-ppm n-hexane plus 200 ppm MEK group in comparison with the 2000-ppm n-hexane only group following 4 weeks' exposure. On the 1st day of exposure, however, coexposure to MEK decreased urinary levels of 2,5-hexanedione dose-dependently.

CONCLUSIONS

The present study showed that urinary concentrations of 2,5-hexanedione increased with potentiation of n-hexane neurotoxicity. Urinary 2,5-hexanedione concentration does not necessarily reflect the exposure concentration of n-hexane in coexposure to n-hexane along with MEK or other solvents, but it may be useful as a marker in the assessment of neurotoxicity in coexposure to n-hexane and other solvents.

Differential expression of the arabidopsis nia1 and nia2 genes. cytokinin-induced nitrate reductase activity is correlated with increased nia1 transcription and mrna levels

Nitrate reductase (NR) activity increased up to 14-fold in response to treatment of Arabidopsis thaliana seedlings with the cytokinin benzyladenine. NR induction was observed in seedlings germinated directly on cytokinin-containing medium, seedlings transferred to cytokinin medium, and seedlings grown in soil in which cytokinin was applied directly to the leaves. About the same level of induction was seen in both wild-type and Nia2-deletion mutants, indicating that increased NR activity is related to the expression of the minor NR gene, Nia1. The steady-state Nia1 mRNA level was increased severalfold in both wild-type and mutant seedlings after benzyladenine treatment. Transcript levels of the Nia2 gene, which is responsible for 90% of the NR activity in developing wild-type seedlings, did not show any changes upon cytokinin treatment. Nuclear run-on assays demonstrated that Nia1 gene transcription increased dramatically after cytokinin treatment.

Dehydrogenase regulation of metabolite oxidation and efflux from mitochondria in intact hearts

To test how alpha-ketoglutarate dehydrogenase (alpha-KGDH) activity influences the balance between oxidative flux and transmitochondrial metabolite exchange, we monitored these rates in isolated mitochondria and in perfused rabbit hearts at an altered kinetics (Km) of alpha-KGDH for alpha-ketoglutarate (alpha-KG). In isolated mitochondria, relative Km dropped from 0.23 mM at pH = 7.2 to 0.10 mM at pH 6.8 (P < 0.05), and alpha-KG efflux decreased from 126 to 95 nmol.min-1.mg-1. In intact hearts, Km was reduced with low intracellular pH, while matching control workload and respiratory rate with increased Ca2+ (pHi = 7.20, perfusate CaCl2 = 1.5 mM; pHi = 6.89, perfusate CaCl2 = 3 +/- 1 mM). Sequential 13C nuclear magnetic resonance spectra from hearts oxidizing [2-13C]acetate provided tricarboxylic acid cycle flux and the exchange rate between alpha-KG and cytosolic glutamate (F1). Tricarboxylic acid cycle flux was 10 mumol.min-1.g-1 in both groups, but F1 fell from a control of 9.3 +/- 0.6 to 2.8 +/- 0.4 mumol.min-1.g-1 at low Km. The results indicate that increased activity of alpha-KGDH occurs at the expense of alpha-KG efflux during support of normal workloads.

p27Kip1 is expressed transiently in developing myotomes and enhances myogenesis

Vertebrate skeletal muscle development is characterized by tight coupling of muscle differentiation with cell cycle arrest in G1/G0. Key regulators of G1 progression are the G1 cyclin-dependent kinases, their positive regulators, the G1 cyclins, and their negative regulators, the cyclin-dependent kinase inhibitors (CDIs). Here we show that p27Kip1 protein, a G1 CDI, is expressed in a prominent but transient wave in the developing myotomes of the mouse embryo. We relate its expression to expression of MyoD and myogenin proteins, which are determination and differentiation class myogenic regulatory factors, respectively. Functional assays showed that ectopic p27 expression can powerfully enhance the efficiency of MyoD-initiated muscle differentiation in cell culture. When considered together with the myotomal expression patterns of p18, p21, and p57, these results suggest a model in which p27 acts as a "trigger" CDI while myoblasts are exiting the cell cycle and initiating differentiation. At later times, when p27 protein has been down-regulated, it is proposed that accumulation of p18, p21, and p57 maintain the differentiated myocytes in a postmitotic state.

Identification of drug metabolites in biological matrices by intelligent automated liquid chromatography/tandem mass spectrometry

A rapid and systematic strategy for the identification of drug metabolites in biological matrices based on liquid chromatography-tandem mass spectrometry (LC/MS/MS) techniques was utilized for the identification of drug metabolites of the HIV protease inhibitor Indinavir. This strategy integrates intelligent realtime mass spectrometry with HPLC detection and a predictive strategy for detecting metabolites arising from common biotransformations, to rapidly elucidate structures of drug metabolites. Structures of metabolites generated from in vitro incubation mixtures of Indinavir were characterized from a single chromatographic analysis using the automated LC/MS/MS methodology, thus reducing data acquisition time and improving efficiency.

Accelerated Alzheimer-type phenotype in transgenic mice carrying both mutant amyloid precursor protein and presenilin 1 transgenes

Genetic causes of Alzheimer's disease (AD) include mutations in the amyloid precursor protein (APP), presenilin 1 (PS1), and presenilin 2 (PS2) genes. The mutant APP(K670N,M671L) transgenic line, Tg2576, shows markedly elevated amyloid beta-protein (A beta) levels at an early age and, by 9-12 months, develops extracellular AD-type A beta deposits in the cortex and hippocampus. Mutant PS1 transgenic mice do not show abnormal pathology, but do display subtly elevated levels of the highly amyloidogenic 42- or 43-amino acid peptide A beta42(43). Here we demonstrate that the doubly transgenic progeny from a cross between line Tg2576 and a mutant PS1M146L transgenic line develop large numbers of fibrillar A beta deposits in cerebral cortex and hippocampus far earlier than their singly transgenic Tg2576 littermates. In the period preceding overt A beta deposition, the doubly transgenic mice show a selective 41% increase in A beta42(43) in their brains. Thus, the development of AD-like pathology is substantially enhanced when a PS1 mutation, which causes a modest increase in A beta42(43), is introduced into Tg2576-derived mice. Remarkably, both doubly and singly transgenic mice showed reduced spontaneous alternation performance in a "Y" maze before substantial A beta deposition was apparent. This suggests that some aspects of the behavioral phenotype in these mice may be related to an event that precedes plaque formation.

Immunoisolation of adult porcine islets for the treatment of diabetes mellitus. The use of photopolymerizable polyethylene glycol in the conformal coating of mass-isolated porcine islets

Functional porcine islets, free of known pathogens, can serve as a source of insulin producing cells for the treatment of experimentally induced insulin dependent Diabetes Mellitus. Porcine islets can be conformally coated (microencapsulated) with a covalently linked, stable permselective membrane while maintaining islet viability and function. The PEG conformal coating is immunoprotective in a discordant xenograft animal model (porcine islets to rat).

[Difference of the discharges from the postganglionic fibers of the celiac ganglion induced by electroacupuncture at zusanli and yanglingquan]

The changes of the discharge from postganglionic fibers of the celiac ganglion induced by electroacupuncture (EA) at Zusanli and Yanglingquan were measured on 25 healthy rabbits. The result shows that the sympathetic activity can be inhibited by EA at both acupoints above. The depression of the sympathetic activity resulted from EA at Zusanli was significant stronger than that at Yanglingquan (P < 0.05). This result indicates that there is the relative individuality in the function of the different acupoints on the different channels.

[Purification and properties of inulinase from Kluyveromyces sp. Y-85]

The crude endocellular inulinase from Kluyveromyces sp. Y-85 was purified to two components, designated as EI and EII, using PEG6000-phosphate buffer extraction, (NH4)2SO4 fractionation, DEAE chromatography and gel filtration (Protein-PAK); The crude exocellular inulinase from this strain was purified to Eexo by means of PEG6000-phosphate buffer extraction, double DEAE-Sephace chromatography, Sephadex G-150 gel filtration. EI, EII and Eexo were demonstrated to be homogeneous by Waters 650E protein purification system. Their molecular weights are 42 kD, 65 kD and 57 kD, respectively. All the inulinases were glycoproteins containing a saccharide (from 25% to 35%) and belonged to the endo-inulinase. In addition, EI, EII, Eexo were optimally reactive at pH4.6, 4.5, 4.6 and at 52 degrees C, 52 degrees C, 55 degrees C, respectively. Ag+, Hg2+ and PCMB inhibited these enzymes' activity strongly. The products of raw inulin extracted from Helianthus tuberosus hydrolyzed by these three enzymes were fructose (86.5%) and glycose (13.5%).

[Study on measures to increase diagnostic accuracy of FNAC of breast masses]

OBJECTIVE

To study the measures capable of increasing the diagnostic accuracy, reducing misdiagnosis as well as giving a full play to fine needle aspiration cytology(FNAC), in the diagnosis of breast masses, and to standardize the diagnostic report form.

METHODS

Totally 1629 cases of FNAC were performed and 444 cases of them were checked with the histological diagnosis.

RESULTS

The sensitivity of diagnosis of malignant tumors in 307 cases, the specificity of diagnosis of benign lesions in 137 cases and the overall accuracy of diagnosis were 95.8%, 98.5% and 96.6% respectively. The false negative rate, potential false positive rate and the overall misdiagnostic rate were 4.2%, 1.5% and 3.4% respectively, while no case of false positive diagnosis was found.

CONCLUSIONS

We believe that: (1) It is very important to use a fine aspirator, to make smears of high quality, to carry out an integrated working procedure and to put into effect a conscientious check over cytological appearance with histological diagnosis. (2) The diagnositc report form introduced in "the uniform approach to breast fine needle aspiration biopsy" by Bethesda specialists is worthy of reference. (3) FNAC can further play important roles in the diagnosis and treatment of breast masses.

Differential regulation of the pre-C and pregenomic promoters of human hepatitis B virus by members of the nuclear receptor superfamily

Synthesis of the pre-C and pregenomic RNAs of human hepatitis B virus (HBV) is directed by two overlapping yet separate promoters (X. Yu and J. E. Mertz, J. Virol. 70:8719-8726, 1996). Previously, we reported the identification of a binding site for the nuclear receptor hepatocyte nuclear factor 4 (HNF4) spanning the TATA box-like sequence of the pre-C promoter. This HNF4-binding site consists of an imperfect direct repeat of the consensus half-site sequence 5'-AGGTCA-3' separated by one nucleotide; i.e., it is a DR1 hormone response element (HRE). We show here that other receptors, including chicken ovalbumin upstream promoter transcription factor 1 (COUP-TF1), human testicular receptor 2 (TR2), and peroxisome proliferator-activated receptors (PPARs) as heterodimers with retinoid X receptors (RXRs), can also specifically bind this DR1 HRE. Synthesis of the pre-C and pregenomic RNAs was affected both in transfected hepatoma cells and in a cell-free transcription system by the binding of factors to this DR1 HRE. Interestingly, whereas some members of the hormone receptor superfamily differentially repressed synthesis of the pre-C RNA (e.g., HNF4 and TR2) or activated synthesis of the pregenomic RNA (e.g., PPARgamma-RXRalpha), other members (e.g., COUP-TF1) coordinately repressed synthesis of both the pre-C and pregenomic RNAs. Thus, HBV likely regulates its expression and replication in part via this DR1 HRE. These findings indicate that appropriate ligands to nuclear receptors may be useful in the treatment of HBV infection.

Body surface Laplacian mapping of bioelectrical activity

A method is described to process and interpret multi-channel bioelectrical signals. The bioelectrical signals were recorded noninvasively over the body surface of human subjects at 120 sites. The body surface Laplacian maps were then constructed from the multi-channel bioelectrical potential measurement. The method was evaluated by means of computer simulations, and applied to imaging cardiac electrical activity. The present investigation suggests body surface Laplacian mapping provides an important means in interpreting bioelectrical signals.

[Clinical application of ultrasound(US)-guided percutaneous microwave coagulation therapy for liver cancer]

OBJECTIVE

To evaluate clinical application of US-guided percutaneous microwave coagulation therapy for liver cancer.

METHODS

32 patients with 57 nodules of liver cancer were treated, 57 nodules were coagulated by 92 times at 182 different points. Output of one coagulation was 60 W last mg 240-300 sec.

RESULTS

The follow-up period was 5-18 months, averaging 10.4 months. 29 patients remained alive, 3 patients died. After treatment, 85.9%(49/57) of the nodules decreased in size; color blood flow signal disappeared in 78.2(36/46) nodules on color and energy Doppler scans; and there was no enhancement in 76.4%(25/34) tumors on enhanced CT scans. In 13 patients with increased AFP level before therapy, it dropped to normal after treatment in 11 patients. Of 27 patients whoes a good general condition was good, 19 patients gained bodies weight. Repeated biopsy in 14 cases showed complete tumor necrosis with fibrosis in 12.

CONCLUSION

US-guided percutaneous microwave coagulation therapy is able to induce total tumor necrosis of liver cancer in most cases. It can be expected as an important non-operative therapy of liver cancer.

[Determination of sulpride in human plasma by high performance liquid chromatography]

This paper describes a reliable method for the pharmacokinetic study of Sulpride in human plasma by reversed-phase high performance liquid chromatography. To compensate the loss of Sulpride during the extraction procedure we used an internal standard very similar in chemical structure and UV absorbance to those of Sulpride. The mobile phase was methanol-water-acetic acid (60:30:1) with a flow rate of 1.2 mL/min. A UV detector was used at 290 nm. The linear range was 5-100 mg/L and the detectable limit was 1.0 mg/L. The recovery and RSD were 97.95%-99.96% and 2.6%-5.1% respectively. The results showed that this method is a sensitive and accurate one which makes the pharmacokinetic study of Sulpride possible. If the concentration was too low to be detected by UV monitor, a fluorescence detector could be used with the excitation wavelength at 299 nm and emission at 342 nm. We analyzed the plasma samples from 30 day-treated psychotic patients and got the satisfactory results.