[Prospect on over early stage treatment of ischemia apoplexy with traditional Chinese medicine].
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Drugs, Chinese Herbal↗
Biomedical subjects
Z Guo
Publications and source records attributed to Z Guo.
[Observation on trachea inner walls of six species of Sect. Stenophora by scanning electronic microscope].
OBJECTIVE: To probe and identify the ultramicro characteristics of trachea inner walls(TIW) of six species of Sect. Stenophora, i.e., Rhizoma Dioscoreae Spongiosae, Rhizoma Dioscoreae Hypoglaucae, Rhizoma Dioscoreae Futschauensis, Rhizoma Dioscoreae Gracillimae, Rhizoma Dioscoreae Tokoro and Rhizoma Dioscoreae Zingiberensis, by scanning electron microscope (SEM). METHOD: The vertical microscopical sections are stuck on the platform of species and metal plated. TIW were observed and photographed by SEM. RESULT: The ultramicro characteristics of TIW, i.e., the smoothnesss of TIW, the existence of separation bands, the density, arrangement types, shapes and sizes of pits, etc., can be seen clearly under SEM. Further, there exist differences in the ultramicro characteristics of each species. CONCLUSION: The above six species of crude drugs can be identified according to their ultramicro characteristics of TIW. SEM can be used to study the ultramicro characteristics of crude drug rhizomas thus creating a new area for identifying crude drugs.
Magnoliopsida↗
[Expression of cell adhesion molecule CD44 variant isoform correlated with the clinical behavior of renal cell carcinoma].
OBJECTIVE: To determinate whether the expression of CD44v in renal cell carcinoma (RCC) is associated with tumor malignant behavior. METHOD: Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect CD44v in 31 human renal cell carcinoma (RCC) in addition to 18 normal renal tissues from patients with non-malignant disease. RESULT: Eighteen RCCs showed positive expression while none of normal renal tissue expressed CD44v (P < 0.001). CD44v was expressed in metastatic or high pathological stage RCC, but the expression of CD44v was not correlated with cellular differentiation. CONCLUSION: Our data indicate that a role for CD44v in human RCC progression and metastases, and CD44v may prove to be a marker for high metastasis potential of RCC.
Adult↗
[Studies on the structure-activity relationship of retinoids--Hansch analysis and 3D-OSAR studies on specific ligands of retinoid x receptor].
Retinoids (Vitamin A, its metabolites and synthetic analogues) play important roles in a variety of biological processes, including cellular differentiation, proliferation and apoptosis. The many diverse actions of retinoids attribute to the ability of regulating transcription of different target genes through activation of multiple retinoid nuclear receptors (RAR of RXR). So, retinoids with selective binding ability to specific receptor may not only have improved therapeutic indices, but may also be invaluable for elucidating the molecular mechanism of retinoidal transcriptional activation. Based on the two dimensional and three dimensional quantitative structure-activity relationships of specific ligands of RXR, we carried out mimesis of environment of ligands interacting with their receptor and, to some extent, mapping the topological and physico-chemical characteristics of receptor. The knowledge of the QSAR study will offer detailed molecular information for design, synthesis and biological evaluation in drug research and development.
Alitretinoin↗
Effect of testosterone on Leishmania donovani infection levels of murine bone marrow derived-macrophages.
AIM: To investigate the effect of the male sex hormone, testosterone (Te), on Leishmania donovani infection levels of bone marrow derived macrophages(BMMs) from female mice of strain C57BL/6J. METHODS: After three weeks of Te-treatment, the BMMs were isolated, challenged with L. donovani at a ratio of 10 to 1 promastigotes per macrophage, and the infection levels of different time points were monitored by Giemsa staining. RESULTS: BMMs from Te-treated mice had a significantly increased initial uptake(3 h post infection, P < 0.05) of promastigotes and carried heavier infection levels at all time points(24 h, 48 h, 72 h post infection, P < 0.01), compared with those from oil treated controls. CONCLUSION: Te can increase L. donovani infection levels of BMMs, being possibly related to Te-induced immunosuppression.
Animals↗
[Simultaneous determination of germanium and molybdenum in mixtures by complexation with 5'-nitrosalicyfluorone and dual-wavelength standard addition spectrophotometry].
In the presence of hexadecyltrimethylammonium bromide and in a medium of 0.3-0.9mol/L sulfuric acid, germanium (IV) and molybdenum (VI) react with 2,6,7-trihydroxy-9 (2'-hydroxy-5'-nitro) phenylfluorone-3, i.e., 5'-nitrosalicyfluorone, to develop red complexes, respectively. The spectra of the two complexes overlap seriously each other, and the additivity of their absorbances is good in the wavelength range of 490-548nm. So a new method for simultaneous spectrophotometric determination of germanium and molybdenum by dual-wavelegth standard addition method has been investigated in detail. The analytical results of five standard mixtures are more accuracy than those obtained by isobestic-point dual-wavelength method. The method has been applied to the analysis of traditional chinese medicine and mineral water with satisfactory results.
Drugs, Chinese Herbal↗
Reduced DNA repair capacity in head and neck cancer patients.
Head and neck cancers (HNCs) are malignancies that can be induced by tobacco use, although host-specific factors such as the DNA repair capacity (DRC) may modulate individual susceptibility to tobacco carcinogenesis. To test the hypothesis that genetically determined DRC modulates HNC susceptibility, we measured the DRC in the peripheral blood lymphocytes of 55 patients with newly diagnosed, previously untreated HNC and 61 healthy controls by the host-cell reactivation assay using a reporter gene damaged by benzo(a)pyrene diol epoxide, an ultimate tobacco-related carcinogen. The mean DRC was significantly lower in cases (8.6%) than it was in controls (12.4%; P < 0.001). The DRC was an independent risk factor for HNC (P < 0.01); those in the middle and lowest tertiles of DRC had increased odds ratios [2.17 (95% confidence interval, 0.74-6.39) and 4.27 (confidence interval, 1.45-12.5), respectively] for HNC. These findings suggest that individuals with reduced DRC may be at increased risk of developing HNC.
7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
Characterizations of Pneumocystis carinii and rat lung lipids: glyceryl ethers and fatty alcohols.
Pneumocystis carinii carinii and rat lung phospholipids contained 3-6% 1-alkyl-2-acyl glycerols composed of the glyceryl ether species, 1-O-octadecyl glycerol (batyl alcohol), 1-O-octadec-9-enyl glycerol (selachyl alcohol), 1-O-hexadecyl glycerol (chimyl alcohol), and 1-O-hexadec-9-enyl glycerol. Of the major phospholipid classes, phosphatidylinositol (PI) and phosphatidylserine contained the highest percentage of alkyl acyl glycerols. Methylprednisolone treatment caused an increase in alkyl acyl PI of rat lung lipids from 12% to 45%. As the PI concentration in lung phospholipids increases in rats treated with methylprednisolone, the increase in alkyl acyl PI was substantial; the proportions of alkyl acyl phosphatidylethanolamine and alkyl acyl lyso phosphatidylcholine (PC) also increased. Pneumocystis phospholipids contained higher proportions of alkyl acyl PC than the phospholipids of the lungs from normal and immunosuppressed uninfected rats. The glyceryl ether compositions of P. carinii carinii PC and lyso PC were similar, which suggests that lyso PC in the organism is derived by phospholipase A2 action on PC. This was not the case for PC and lyso PC of the lung controls. Analysis of the free fatty alcohols, precursors of glyceryl ethers identified only saturated species in P. carinii carinii and rat lung controls. Thus, the introduction of a double bond in the alcohol moiety of glyceryl ethers occurs after formation of the ether linkage between fatty alcohol and the glyceryl backbone.
Animals↗
Evaluation of sink effects on VOCs from a latex paint.
The sink strength of two common indoor materials, a carpet and a gypsum board, was evaluated by environmental chamber tests with four volatile organic compounds (VOCs): propylene glycol, ethylene glycol, 2-(2-butoxyethoxy)ethanol (BEE), and Texanol. These oxygenated compounds represent the major VOCs emitted from a latex paint. Each chamber test included two phases. Phase 1 was the dosing/sorption period during which sink materials (pieces of carpet and gypsum board samples) were exposed to the four VOCs. The sink strength of each material tested was characterized by the amount of the VOCs adsorbed or absorbed. Phase 2 was the purging/desorption period during which the chambers with the dosed sink materials were flushed with purified air. The reemission rates of the adsorbed VOCs from the sinks were reflected by the amount of the VOCs being flushed. Phase 1 results indicated that the sink strength for the four target compounds is more than 1 order of magnitude higher than that for other VOCs previously tested by the U.S. Environmental Protection Agency (EPA). The high sink strength reflected the unusually high sorption capacity of common indoor materials for the four VOCs. Phase 2 results showed that reemission was an extremely slow process. If all the VOCs adsorbed were reemittable, it would take more than a year to completely flush out the VOCs from the sink materials tested. The long reemission process can result in chronic and low-level exposure to the VOCs after painting interior walls and surfaces.
Air Pollution, Indoor↗
Comparative molecular field analysis of a series of paclitaxel analogues.
A series of 94 paclitaxel analogues exhibiting antitumor activity by promoting the assembly of microtubules and inhibiting the disassembly process of microtubules to tubulin were investigated using the comparative molecular field analysis (CoMFA) method. These compounds belonging to 10 structural classes were randomly divided into a training set of 80 compounds and a test set of 14 compounds. Since the three-dimension structure of ligand--receptor complex is unknown, from X-ray and NMR data we rationally selected the three-dimension structure of paclitaxel in a polar solution as the active conformation and starting structure for molecule modeling, the other molecules were aligned using this molecule model as the template. The most optimal CoMFA yielded a two-components model, with significant cross-validation r2cv of 0.640 and conventional r2 of 0.868. The predictive ability of training set model was tested on the test set of 14 compounds. The tests not only revealed the robustness of the CoMFA model but demonstrated that for our model r2pred based on the mean activity of test set compounds can accurately estimate external predictivity but r2pred based on the mean activity of training set compounds overestimated the model. The CoMFA model explained why the activity of taxoid is sensitive to the stereochemistry of the atoms at C-2' and C-3' positions and the presence of hydroxyl group at C-2' position. The other factors affecting activity were also elucidated according to standard coefficient contour maps of steric and electrostatic fields derived from the CoMFA model.
Antineoplastic Agents↗
Phospholipid transfer protein can transform reconstituted discoidal HDL into vesicular structures.
The present study investigated the effect of phospholipid transfer protein (PLTP) on transformation of discoidal HDL (d-HDL) to vesicular structures by using primarily KBr density gradient centrifugation, non-denaturing gradient gel electrophoresis, and electron microscopy. The incubation of reconstituted d-HDL preparations containing apo-AI with PLTP resulted in the formation of vesicular structures differing in hydrated densities and sizes. The extents of transformation were dependent upon PLTP concentrations and incubation times. Substantial transformations occurred, even with plasma concentrations of PLTP, within 4 h of incubation at 37 degrees C. After 8 h of incubation, almost 80% of d-HDL was converted to vesicular structures with a hydrated density of 1.07 g ml-1. The d-HDL-vesicle transformation appeared to be triggered by the PLTP-mediated displacement of apo-AI. This apo-AI displacement might have led to the fusion of transiently produced apo-AI deficient particles, producing thermodynamically stable vesicular structures. The cross-linking of apo-AI in d-HDL almost completely prevented d-HDL-vesicle transformation. The addition of free apo-AI to the PLTP/d-HDL incubation mixtures also greatly reduced the transformation. The conversion of smaller vesicles of density 1.07 g ml-1 to larger vesicles of density 1.05 g ml-1 also seemed to have been affected by PLTP-mediated apo-AI displacement. We described the possible implications of the transformation of d-HDL into vesicular structures in lipid and lipoprotein transport processes under physiological and pathological conditions.
Apolipoprotein A-I↗
Platination of a GG site on single-stranded and double-stranded forms of a 14-base oligonucleotide with diaqua cisplatin followed by NMR and HPLC -- influence of the platinum ligands and base sequence on 5'-G versus 3'-G platination selectivity.
Detailed studies of the kinetics of platination of the single-stranded 14-base DNA oligonucleotide d(ATACATGGTACATA) and the corresponding duplex by cis-[Pt(NH3)2(H2O)2]2+ show that HPLC and NMR are complementary methods which provide similar results. The 5'-G and 3'-G monofunctional intermediates were trapped, separated and characterized by NMR (via 15NH3 labeling) and enzymatic digestion followed by mass spectrometry. The kinetic data are compared with those for the corresponding reactions of cis-[PtCl2(NH3)2] (cisplatin) and its monohydrolysed analogue. For both single and double strands of the oligonucleotide, the aqua complex shows little selectivity for the 5'-G or the 3'-G in the initial platination step, whereas the chloro-complex preferentially platinates the 3'-G. The base on the 3' side of the GG sequence appears to play an important role in controlling this selectivity; replacement of T by C increases the selectivity of duplex platination by the diaqua complex by a factor of about 6, and the selectivity of chelation of the 3'-G monofunctional adduct by a factor of about 3. In general the reactivity of the 5'-G in a GG sequence appears to be enhanced in a duplex compared with a single-strand. For both the aqua-monoadduct and chloro-monoadduct, cis-[Pt(NH3)2(N7G)(H2O or Cl)], the 5'-G monoadduct is much longer lived (t1/2 approximately 4 h at 288 K for aqua, 80 h at 298 K for chloro) than the 3'-G monoadduct (t1/2 < or = 45 min at 288 K for aqua, 6 h at 298 K for chloro). Inspection of molecular mechanics models of the end states of various monofunctional adducts provided insight into H-bonding and destacking interactions in these adducts and the sequence selectivity observed in their formation. Such adducts may play an important role in the mechanism of action of platinum anticancer drugs.
Base Sequence↗
Exploring the folding free energy surface of a three-helix bundle protein.
The multidimensional free energy surface for a small fast folding helical protein is explored based on first-principle calculations. The model represents the 46-residue segment from fragment B of staphylococcal protein A. The relationship between collapse and tertiary structure formation, and the order of collapse and secondary structure formation, are investigated. We find that the initial collapse process gives rise to a transition state with about 30% of the native tertiary structure and 50-70% of the native helix content. We also observe two distinct distributions of native helix in this collapsed state (Rg approximately 12 A), one with about 20% of the native helical hydrogen bonds, the other with near 70%. The former corresponds to a local minimum. The barrier from this metastable state to the native state is about 2 kBT. In the latter case, folding is essentially a downhill process involving topological assembly. In addition, the order of formation of secondary structure among the three helices is examined. We observe cooperative formation of the secondary structure in helix I and helix II. Secondary structure in helix III starts to form following the formation of certain secondary structure in both helix I and helix II. Comparisons of our results with those from theory and experiment are made.
Hydrogen Bonding↗
Rho proteins play a critical role in cell migration during the early phase of mucosal restitution.
In the intestine, several growth factors stimulate migration of epithelial cells, contributing to the maintenance of tissue integrity. The Ras-like GTPase Rho regulates a signal transduction pathway linking growth factor receptors to the formation of actin stress fibers and focal adhesions, presumed to be important for motility. Using an in vitro wound-induced migration assay, we have examined the role of Rho GTPases in the migration of IEC-6 and Caco-2 cells, and provide evidence that the Rho GTPases play an essential role in the initial phase of mucosal wound healing. Treatment of the cells with Clostridium difficile toxins A and B, inhibitors of the Rho family GTPases inhibited migration in a dose-dependent fashion. Microinjection of the inhibitory exchange factor Rho-guanine nucleotide dissociation inhibitor (GDI), or Clostridium botulinum C3 ADP-ribosyl transferase (C3) toxin, a Rho-ADP-ribosylating exoenzyme, potently inhibited migration. Microinjection of RhoT19N, a dominant negative form of RhoA, or in vitro ADP-ribosylated RhoA impaired the ability of cells to migrate. Rho-GDI and C3 exoenzyme also inhibited EGF-induced migration of IEC-6 cells. These results demonstrate that Rho is required for endogenous and EGF-induced migration of small intestinal crypt cells, and that Rho proteins are essential elements of a mechanism by which growth factors induce cell migration to restitute mucosal integrity.
ADP Ribose Transferases↗
Blood pressure and performance on the Mini-Mental State Examination in the very old. Cross-sectional and longitudinal data from the Kungsholmen Project.
The authors examined the association of blood pressure with cognitive function as assessed by the Mini-Mental State Examination (MMSE) in a community-based Swedish cohort of 1,736 people aged 75-101 years. Age, sex, education, antihypertensive medication use, heart disease, and stroke were considered as covariates. Multiple linear regression analysis indicated that both systolic and diastolic blood pressure, measured in 1987-1989, were positively and significantly related to baseline MMSE score; baseline systolic pressure was also positively and significantly related to follow-up MMSE score, measured after an average period of 40.5 months among subjects who were not taking antihypertensive medication at baseline. Furthermore, in the nontreated group, multiple logistic regression showed that individuals with a baseline systolic pressure less than 130 mmHg had an odds ratio of 1.88 (p = 0.05) for follow-up cognitive impairment (MMSE score < 24) compared with those whose systolic pressure was 130-159 mmHg. An increased but not statistically significant risk of cognitive impairment was associated with high blood pressure (systolic pressure > or = 180 mmHg or diastolic pressure > or = 95 mmHg) only in persons taking antihypertensive medication at baseline. Subjects with systolic pressure of 160-179 mmHg tended to be at lower risk of cognitive impairment. These results may support the view that a certain blood pressure level, particularly a systolic pressure of at least 130 mmHg, is important to the maintenance of cognitive functioning in the very old. They also suggest that severe hypertension that is not well controlled (systolic pressure > or = 180 mmHg or diastolic pressure > or = 95 mmHg) is still a threat to cognitive function in this age group. However, the use of blood pressure measurements made at a single visit and the relatively short follow-up period should be considered when interpreting these results.
Aged↗
Ligation-mediated PCR amplification of specific fragments from a class-II restriction endonuclease total digest.
A method is described which permits the ligation- mediated PCR amplification of specific fragments from a Class-II restriction endonuclease total digest. Feasibility was tested using Bcl I and phage lambda DNA as a model enzyme and amplicon system, respectively. Bcl I is one of many widely used restriction enzymes which cleave at palindromic recognition sequences and leave 5'-protruding ends of defined sequence. Using a single pair of universal primers, a given fragment can be specifically amplified after joining the fragments to adaptors consisting of a duplex primer region and a 9-nucleotide protruding single-stranded 5'-end containing the sequence complementary to the cleaved restriction site and a 4-nucleotide 'indexing sequence.' The protruding strand anneals to a restriction fragment by displacing its corresponding strand in the same fragment-specific indexing sequence located juxtaposed to the restriction site. The adaptor is covalently linked to the restriction fragment by T4 DNA ligase, and amplification is carried out under conditions for long-distance PCR using the M13 forward and reverse primers. The technique discriminated robustly between mismatches and perfect matches for the 16 indexing sequences tested to allow individual lambda Bcl I fragments to be amplified from their respective adaptor pairs. A strategy is proposed enabling a non-cloning approach to the accession, physical mapping and sequencing of genomic DNA. The method could also have application in high-throughput genetic mapping and fingerprinting and should expand the enzyme base for ligation- mediated indexing technology which has previously been limited to the Class-IIS and IP restriction endonucleases.
Bacteriophage lambda↗
Prolongation of rat islet allograft survival by the immunosuppressive agent leflunomide.
The purpose of this study was to investigate the effect of Leflunomide (Lef), alone or in combination with a suboptimal dose of cyclosporine (CsA), on rat allogeneic islet transplantation. Two thousands islets were transplanted under the left kidney capsule of a streptozocin-induced diabetic Lewis recipient. In the ACI to Lewis combination, the mean survival time (MST) of the untreated group was 5.2 +/- 0.8 days. Lef at 2.5, 5, and 10 mg/kg/day for 14 days significantly prolonged MSTs to 19.0 +/- 1.6, 29.8 +/- 3.7, and 29.0 +/- 5.3 days (P<0.01), respectively. CsA at 5 mg/kg/day also prolonged graft survival to 21 +/- 3.5 days. When CsA (5 mg/ kg/day) was combined with Lef (5 or 10 mg/kg/day) and administered for 14 days, the survival rate of the islet allografts was further increased to 34.8 -/+ 4.7 and 36.0 -/+ 6.6 days, respectively. When Lef or CsA monotherapy was extended to 28 days at a dose of 5 mg/kg/ day, MSTs were further increased to 45.8 -/+ 8.8 or 37.4 -/+ 4.7 days, respectively. Graft MST was 56.4 -/+ 9.9 days when Lef and CsA combination therapy was administered for 28 days. In the Brown-Norway to Lewis combination, MST of the allogeneic islets in untreated rats was 6.2 -/+ 0.8 days. When Lef or CsA alone, at 5 mg/kg/day, was administered for 28 days, two of seven Lef-treated rats remained normoglycemia for more than 100 days. Graft survival longer than 100 days occurred in one of five CsA-treated rats, and in five of eight rats treated with the combination of Lef and CsA. The graft-bearing left kidney was removed after 100 days in rats with functional islet allografts, and a second Brown-Norway islet graft was transplanted into the right kidney. In all recipients, the second graft was rejected by 9.8 -/+ 1.5 days. In summary, our findings demonstrate that Lef prolonged allogeneic islet graft survival, and its immunosuppressive effect was improved when combined with CsA.
Animals↗
In vivo effects of leflunomide on normal pancreatic islet and syngeneic islet graft function.
Leflunomide (Lef) is a novel immunosuppressant that can prevent islet allograft and xenograft rejection. In this study, we investigated the in vivo effects of Lef on the function of normal pancreatic islets and syngeneic islet grafts in rats and compared its effect to cyclosporine (CsA) and FK506. Different groups of rats were treated with Lef (10 and 20 mg/kg/day), CsA (20 mg/kg/day), or FK506 (2 mg/kg/day). After 4 and 6 weeks, nonfasting blood glucose (BG) levels of all the treatment groups were not different from that of the control group. Intravenous glucose tolerance test revealed that the rate of glucose disappearance was normal in Lef-treated groups. However, the rate of glucose disappearance in the CsA- and FK506-treated rats was impaired. In contrast, long-term (7 months) treatment of rats with CsA (10 mg/kg/day) resulted in five of seven rats developing hyperglycemia. However, normal BG was observed in all rats treated for 7 months with Lef (10 mg/kg/day). In the second experimental model, streptozocin-induced diabetic ACI rats were grafted with an average of 1200 syngeneic islets into the liver or kidney capsule. Diabetes in these ACI recipients was stably reversed for 6 months, then these rats were treated with Lef (20 mg/kg/day), CsA (20 mg/kg/day), and FK506 (2 mg/kg/day). After 14 days of treatment, nonfasting BG levels were significantly increased in rats treated with CsA (before: 105 +/- 2.9 mg/ dl, after: 275.8 +/- 60 mg/dl) as well as in rats treated with FK506 (before: 108 +/- 2.4 mg/dl, after: 209 +/- 10.1 mg/dl). In contrast, the BG levels of the Lef-treated rats were indistinguishable from those of the untreated control groups. Site of transplantation, i.e., liver and kidney, did not affect the results. Our results indicating that Lef has no diabetogenic property in vivo lends support to the promise that leflunomide may be effective for clinical islet transplantation.
Animals↗