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Biomedical subjects

Z R Guo

Publications and source records attributed to Z R Guo.

At least 19 recordsLinked to original sources
PubMed2001

[Effect of improved topical agents on healing time of deep second-degree burn wound].

OBJECTIVE: With the recognization of the mechanism of wound healing, some topical agents are created and applied in trauma to improve the healing rate of wounds. The main purpose of this study is to investigate the effect of some topical agents on the healing rate of deep second-degree burn wounds. METHODS: One thousand five hundred and sixty-three patients with deep second-degree burn wounds(total burn surface area < or = 10%) were involved in this study from January 1982 to December 1999. According to the application time of different treating measures including supplement of Zn, application of growth factors and collagenase, the patients were divided into 3 groups, wound healing rates were compared. RESULTS: Before 1991, none of special topical agents were used, and the healing time of deep second-degree burn wounds was(23.8 +/- 3.5) days. From 1991 to 1996, with the topical application of SD-Ag-Zn, which can provide Zn for cells taking part in wound healing, the healing time of deep second-degree burn wounds was (20.6 +/- 3.2) days, earlier than no special topical agents (P < 0.05). From 1997 to 1999, growth factors such as basic fibroblast growth factor(bFGF) and epithelial growth factor (EGF) and collagenases were applied in wound treatment combining with SD-Ag-Zn, wound healing time was (16.2 +/- 2.8) days, earlier than no special topical agents (P < 0.01) and simple SD-Ag-Zn application (P < 0.05). CONCLUSION: It indicates that the improvement of topical agents can accelerate wound healing speed.

Adolescent↗
PubMed2001

[Inhibitory effects of benzoisoselenothiazolidone sulfonamide derivatives on cyclooxygenase].

AIM: To study the inhibitory effects of benzisoselenothiazolidone sulfonamide derivatives on cyclooxygenase. METHODS: 6-Keto-PGF1 alpha and PGE2 were assayed by radioimmunoassay (RIA) method; mRNA expression of COX-1 and COX-2 were assayed by reverse transcription-polymerase chain reaction (RT-PCR) method. RESULTS: Compound A [N-4-(4-methoxyphenyl-aminosulfonyl)-benziososelenothiazolidone] and B [N-4-(4-fluorophenyl-aminosulfonyl)-benzoisoselenothiazolidone] were two benzoisoselenothiazolidone sulfonamide derivatives, which can inhibit COX activity with IC50 of 1.5 x 10(-8) mol.L-1 and 5.0 x 10(-8) mol.L-1 for COX-2, as well as IC50 of 1.5 x 10(-5) mol.L-1 and 2.8 x 10(-5) mol.L-1 for COX-1. The ratio of IC50 COX-1/IC50 COX-2 of compound A and B are 1,000 and 560, respectively. They both can inhibit COX-2 mRNA expression in cultured rat peritoneal macrophages stimulated with LPS (1 microgram.mL-1), and have no effect on COX-1 mRNA expressions. CONCLUSION: Compound A and B, two benzoisoselenothiazolidone sulfonamide derivatives, both are selective inhibitory agents of COX-2, and possess inhibitory effects on 5-lipoxygenase and cyclooxygenase.

Animals↗
PubMed2001

[Study on 3D-QSAR of PPAR gamma agonists with thiazolidinedione and arylketo-acid moieties].

AIM: To build a model of two series of PPAR gamma agonists--thiazolidinedione and aryketo-acid derivatives using 3D-QSAR method, and to reveal the structural features affecting the binding activity to PPAR gamma, which relates to antihyperglycemic and antihyperlipidemic activity and has a potential application to the treatment of type II diabetes. METHODS AND RESULTS: 48 agonists with selective activity for PPAR gamma were analyzed using CoMFA. Based upon the active conformation of rosiglitazone (BRL) extracted from its complex with PPAR gamma all agonists were aligned. The model from CoMFA showed a high ability to explain and predict the activity of PPAR gamma agonists with cross-validation correlation coefficient R2 = 0.656, that of non-cross-validation R2 = 0.982, F10,37 = 201.1, and SE = 0.115. CONCLUSION: The CoMFA contour map indicates that the steric fields mainly contribute to the binding effect, and especially a bulk group in the arylketo-acid series favors in the increase of affinity for PPAR gamma, as compared to the thiazolidinedione.

Benzophenones↗
PubMed2001

[Synthesis of triphenylethylene with aliphatic cyclic moiety and its antagonism on estrogen receptor].

AIM: In order to improve the biological activity and reduce the side effects and toxicity, a series of novel estrogen receptor antagonists were designed. METHODS: The key triphenylethylene intermediates were obtained by the McMurry reaction. The target compounds were prepared by etherification. The binding affinities of the target compounds for the estrogen receptor in rat uterine cytosol were measured by a competitive binding assay and their estrogen agonistic/antagonistic properties were investigated in the 3-day uterine weight assay in the immature rats. RESULTS: Thirty-five new compounds have been synthesized and their geometric configuration were determined by X-ray crystallography and 1HNMR spectral data. CONCLUSION: All of the test compounds showed affinity for the estrogen receptor (IC50 < 10(-6) mol.L-1), especially compound 35 with IC50 1.07 x 10(-8) mol.L-1. Some compounds are antagonists, inhibiting uterus growth; others are agonists, promoting uterus growth. Compounds 14 and 27 are superior antagonists to tamoxifen.

Animals↗
PubMed2001

[Three dimensional quantitative structure-activity relationship of heterocyclic-compounds with di-tert-bultylphenyl inhibitors].

AIM: To quatitatively disclose the relationship between activity and structure of a new class of COX-II inhibitors containing dialkylphenyl-linked heterocyclic moieties. METHODS AND RESULTS: Seventeen COX-II inhibitors from literature as a training set were investigated with the aim of developing a 3D-QSAR model using comparative molecular field analysis (CoMFA). To reveal the pharmacophoric pattern, several modes of superimposition were explored. The significant model shows a higher ability to explain and predict the activity of COX-II inhibitors, with the cross-validation RCV2 = 0.718, non cross-validation R2 = 0.992, F = 260,624, and SEE (standard error of estimate) = 0.072. Three compounds were selected as a predicting set, the low deviations of calculated values from the measured ones suggesting a powerful predictive ability of the model. CONCLUSION: The 3D-QSAR explains the dependence of COX-2 inhibition upon the structures of the compounds. Some structure information for design of new COX-II inhibitors with higher activity has been given.

Cyclooxygenase 2↗
PubMed2001

[Three dimensional quantitative structure-activity relationship of farnesyl protein transferase inhibitors].

AIM: To build a three dimensional structure model that correlates the biological activities and the structures of a series of farnesyl protein transferase (FPT) inhibitors exemplified by the compound of 2, 3,4,5-tetrahydro-1-(1H-imidazol-4-ylmethyl)-4-(2-biphenylylcarbonyl)-1H-1, 4-benzodiazepine. METHODS AND RESULTS: Thirty-two FPT inhibitors with two types of scaffold were analyzed. Active conformations of which were studied using system search, a 3D-QSAR model were constructed using the method of comparative molecular field analysis (CoMFA). The resulting of cross-validated RCV2 = 0.602, non-cross-validated R2 = 0.958, SE = 0.270 and F = 124.5 indicate that the 3D-model possesses an ability to predict activities of new inhibitors. CONCLUSION: The information of CoMFA model offers an approach to designing new FPT inhibitors.

Alkyl and Aryl Transferases↗
PubMed2000

[Expression and characterization of HIV-1 Gag p17-p24 protein].

The biological and immunological characteristics of HIV-1 core protein p17-24 expressed by recombinant vaccinia viruses were studied. The results of indirect immunofluorescence assay (I-IFA), Western blot and dot ELISA showed that the two recombinants could express the p24 gag and p17-24 gag fusion proteins in infected cell lines respectively. The electromicroscope observation revealed that the expressed proteins could also assemble into virus-like particles. The recombinant vaccinia viruses can also stimulate mice for the formation of anti HIV-1 Gag p24 antibody. When infected with the recombinant viruses, the chromosome DNA ladder caused by the apoptosis of the BHK cell was observed.

Animals↗
PubMed1999

2-Carboxymethylendothal analogues as affinity probes for stabilized protein phosphatase 2A.

Endothal (1diacid) and [3H]cantharidic acid ([3H]CA) bind with high affinity to the catalytic subunit of protein phosphatase 2A (PP2A). PP2A in liver cytosol was greatly stabilized with 30% glycerol as a preliminary step in the potential use of endothal-type derivatives for affinity chromatography. We report here the first introduction of a functionalizable group into endothal which allows retention of binding site affinity (assayed as [3H]CA binding in mouse liver cytosol). 2-Carboxymethylendothal anhydride (7) was prepared in two steps and 97% overall yield from cis-aconitic anhydride and furan. The potency of 7 was retained on conversion to two 2-carboxymethyl esters but not to two 2-(n-alkylcarboxamidomethyl) analogues.

Affinity Labels↗
PubMed1999

[Effects of basic fibroblast growth factor on the healing of cutaneous chronic wounds].

OBJECTIVE: To observe the effects of basic fibroblast growth factor(bFGF) on the healing of cutaneous chronic wounds. METHODS: Twenty-eight cases with thirty-three wounds from trauma, diabetes, pressure and radiation injuries were locally treated with bFGF in a dosage of 150 U/cm2 wounds. The healing time of wounds was used to evaluate the treatment results. RESULTS: The healing time in all of chronic wounds were accelerated. All wounds from trauma, diabetes and pressure were healed within 4 weeks and another 2 wounds from radiation injuries were healed over 4 weeks. The healing rate within 4 weeks was 93.9%. CONCLUSION: The results indicate that bFGF can be used as a promoter to accelerate the healing of chronic wounds in clinic.

Adolescent↗
PubMed1997

Anisodamine restores bowel circulation in burn shock.

In a group of eight burn patients with a mean of 65.3 +/- 17.4 per cent TBSA burn injury (range 50-90 per cent TBSA), accompanied by a mean of 43.5 +/- 18.9 per cent TBSA full-thickness injury, it was shown that the evidence of global hypovolaemia had disappeared at 12 h after the injury following aggressive fluid resuscitation, while there was still a subnormal pHi of stomach at 48 h. As a prolonged period of inadequacy of oxygen delivery to the intestine might result in impairment of the intestinal mucosal barrier function, and then endogenous endotoxaemia might ensue, it seems to be important to correct intestinal hypoxia as early as possible. Since the inadequate perfusion to the gut wall is due to selective vasoconstriction of the mesenteric vasculature, logic dictates that the use of a vasodilator is in order. Anisodamine, an anticholinergic drug, was then given in six burn patients with comparable burn size and amount of fluid replenishment with the eight patients in the control group. It was clearly demonstrated that gastric pHi returned to normal before 48 h after injury. Plasma endotoxin and TNF contents were measured, and they were significantly lower than control values after 72 h. In conclusion, it is believed that anisodamine might be a valuable adjunct to the resuscitation regime of burn shock, and, therefore, a promising drug to abate endogenous endotoxaemia subsequent to splanchnic vasoconstriction due to hypovolaemia. The shortcomings of the drug were a mild abdominal distention and tachycardia after its administration.

Adult↗
PubMed1997

[Study on the structure-activity relationships of retinoids. II. 3D-QSAR of retinoids and receptor interaction].

Precise prediction of the binding constant of ligand to receptor is an important aspect of structure-based drug design. Almost all methods including de novo design and 3D database search are over concentrated on structure generation rather than quantitative evaluation of the binding properties of the newly produced molecule. Using epididymal retinoic acid binding protein (ERABP) as a model, we simulated the interaction between retinoids and their receptor with DOCK program and obtained an equation for predicting the binding constants. According to the docking conformers of the ligands, CoMFA was also used to deduce a pharmacophoric model of this series of compound.

Receptors, Retinoic Acid↗
PubMed1997

[Studies on retinoids. IV. Design, synthesis and structure-activity relationships of di-t-butylphenyl compounds].

Retinoic acid and its analogues play important roles in modulating cell growth, differentiation, immunity and apoptosis. Clinically they are used for cancer chemoprevention and chemotherapy. Based upon the moiety of 3,5-di-t-butyl-4-hydroxy phenyl ring, a series of substituted aromatic amide, ester and chalcones were designed and synthesized, which mimic the molecular shape, size, and spacial disposition of functional groups of retinoic acid. The general structure is as follows: [formula: see text] where R stands for hydrogen atom or methyl group, Y is the linkage -CONH-, -NHCO-, -COO-, -COCH = CH-, or a member of a heterocycle, X represents various substituents at different positions. The SAR indicates that the presence of hydrophobic group(s) at one end of the molecule, and a carboxyl group at the other end, and a conjugative system of molecule are necessary and full prerequisite for exhibiting activity. Loss of any one factor of them will abolish the activity. Being obligatory for anti-oxidative effect, the phenolic hydroxy group does not convey biological activity, because after methylation of the hydroxy group the compound increases the differentiation-inducing activity and loses the anti-oxidative effect, indicating that there is no correlation between the two activities. With a stable conformation of two phenyl rings with cis-conformation N-methylated acyl amide (No. 30) features in bent shape of the molecule, instead of an extended conformer, which is taken by the non-N-methylated partner and all-trans retinoic acid. A bent conformer of No. 30 accounts for the inactivity. In this paper compounds No. 4f, 4g, 5a, 7, 13, 32, 37, and 38 exhibited significant activity among them 4-[3-(3, 5-di-t-4-methoxyphenyl)-3-oxo-1-propenyl] benzoic acid (No. 38) showed high activity comparable to that of retinoic acid. The pharmacological action of No. 38 is under investigation.

Benzoates↗
PubMed1997

[Synthesis and biological activity of tyrosine protein kinase inhibitors].

Four classes of 25 tyrosine protein kinase (TPK) inhibitors were designed and synthesized. Compounds 1-10 were tested to inhibit TPK of HL-60 leukemia cell using 32P-ATP method, and some of them exhibit evident inhibitory activities. Their structure-activity relationship is similar to that of TPK inhibitors reported in literatures. Compounds 11-25 were tested to inhibit TPK of normal rat spleen cell using ELISA method and their SAR is different from that using 32P-ATP method.

Animals↗
PubMed1997

[Clinical study of combined acupuncture-drug anesthesia for anterior approach cervical discectomy].

OBJECTIVE: To observe the effect of combined acupuncture-drug anesthesia for anterior approach cervical discectomy. METHODS: Fifty patients scheduled for anterior approach cervical discectomy were randomized into two groups, the control group (5% procaine combined with drug anesthesia, n = 25), and the experiment group (combined acupuncture-drug anesthesia, n = 25). In the experiment group, bilateral acupoints of Neiguan (P6) and Hegu (LI4) of the patients were stimulated for 30 minutes by Hans Acupoint Nerve Stimulator through skin electrode while a combination of dolantin 25 mg and droperidol 2.5 mg were administered intravenously during induction. RESULTS: There was no statistical difference of hemodynamic variation between the two groups (P < 0.05). The experiment group could also provide the same anesthesia effect as control group did, as well as it had less postoperative complications, more rapid recovery with less expense. CONCLUSIONS: The acupuncture-drug anesthesia for anterior approach cervical discestomy is feasible and it is worthwhile to be widely used in clinical practice.

Acupuncture Analgesia↗
PubMed1996

[Structure-activity relationship studies of chalcones as SRS-A receptor antagonists].

A simple, reliable and highly sensitive bioassay with sensitized longitudinal strips of guinea pig ileum was used for screening the receptor antagonists of slow reacting substance of anaphylaxis (SRS-A). The SRS-A receptor antagonistic activities of 17 chalcones were studied. Most compounds in these chalcones were found to have SRS-A receptor antagonistic action at the concentration of 10(-4) mol.L-1. Among them, compounds 5, 13 and 17 were highly effective with IC50s of 7.5 x 10(-6), 7.5 x 10(-6) and 6.8 x 10(-5) mol.L-1, respectively. Under the same conditions, the IC50 of FPL 55712, a known leukotriene D4 receptor antagonist, was shown to be 3 x 10(-4) mol.L-1. It would appear that compounds 5, 13 and 17 were 40, 40 and 4.4 times more potent, respectively, than FPL 55712. From analysis of structure-activity relationship of chalcones, these results suggest that the following factors may be important for an active antagonist of SRS-A receptors: (a) There is a system of pi, pi conjugation in the molecule; (b) The ester group in the B ring of chalcones is more favorable than the carboxyl group; (c) Antagonism for meta- or para-substituted derivatives of carboxyl or ester group in the B ring are more potent than ortho-substituted compounds; (d) The length of carbon chain of alkyl group in the A ring of chalcones is more effective for 1, 4 or 6 carbon atoms than for 10 or 14 carbon atoms.

Animals↗
PubMed1995

Extensive wound excision in the acute shock stage in patients with major burns.

In order to reduce excessive plasma loss, to alleviate the effects of devitalized tissues on the body, and to shorten the time in hospital, we attempted to perform extensive escharectomy during the shock period in extensively burned patients. Group A consisted of 21 patients, aged 9-45 years, with a mean total burn area of 63.2 +/- 18.1 per cent TBSA, and full-thickness injury involving 35.9 +/- 19.6 per cent TBSA. The first escharectomy was performed at 24.1 +/- 13.9 h postburn. The excision area averaged 32.3 +/- 6.7 per cent TBSA (range 24-96 per cent). In 15 patients a Swan-Ganz catheter was introduced to monitor haemodynamic changes. It was found that RAP, PAP, PAWP, ABP, HR, CO and CI were all stable during and after the operation. Group B consisted of 29 patients, and escharectomy was begun 4-5 days postburn. The mean healing time of the patients in group A was 33.1 days, which was shorter than that in group B (40.1 days). The period of haemoconcentration was shorter in group A and the amount of blood required during the first 2 weeks was almost 700 ml less in group A. There were fewer visceral complications in group A and smaller amounts of antibiotics were required in this group. The authors believe that escharectomy during the shock stage is feasible.

Acute Disease↗