Medical history and the science of medical history.
Explore the source record for details and available documents.
Historiography↗
Biomedical subjects
Z Cheng
Publications and source records attributed to Z Cheng.
[Advances in the education of medical history, spreading dialectical materialism].
Explore the source record for details and available documents.
China↗
[The feature of pancreatic microcirculatory impairment in caerulein induced acute pancreatitis].
OBJECTIVE: To study the feature of pancreatic microcirculatory impairment in caerulein-induced acute pancreatitis. METHODS: The AP model of subcutaneous injection of caerulein was studied by intravital fluorescence microscopy of erythrocytes labeled by FITC (FITC-RBC) and by scanning electron microscopy of vascular corrosion casts and light microscopy of Chinese ink-injected/cleared tissues. RESULTS: Animals treated with caerulein showed hyper-amylases. Contractions of intralobular arteriolar sphincter, presence of vacuoles in all the layers of sphincter, gross irregularity in capillary network of acini were observed in caerulein-induced groups. The decrease of pancreatic capillary blood flow (P < 0.01), reduction of functional capillary density, and irregular intermittent perfusion (P < 0.05) were found. CONCLUSIONS: Impairment and contraction of pancreatic intralobular arteriolar sphincter are the initial microcirculatory lesions in the early phase of acute pancreatitis induced by Caerulein, and play a key role in the pancreatic ischemia and pancreatic microvascular failure in acute pancreatitis.
Acute Disease↗
[Experimental study of oxygen supply and demand balance during total hepatectomy and partial liver replantation with venous bypass technique in young pigs].
OBJECTIVE: To investigate the changes of oxygen supply and demand balance during total hepatectomy and partial liver replantation(TCH and PLRP) with venous bypass technique in pigs. METHODS: Seven young pigs[weight (24.2 +/- 4.8) kg] were anesthetized with fentanyl and pentobartal. Catheters were inserted into portal vein via splenic vein and into vena cava inferior via right femoral vein, respectively, and the two catheters were connected by a "Y" adaptor to right atrium via extracorporeal circulation pump. Venous bypass technique was used during occlusion of total hepatic blood stream(OTHB). SvO2, hemodynamics and blood gas analysis were measured after anesthesia, during and 30 minutes after venous bypass. RESULTS: SvO2 was decreased significantly(P < 0.05), vein bypass technique ameliorated partially the disturbance of hemodynamics, and there was correlation between CO and SvO2 during THC and PLRP in pigs. CONCLUSION: The results suggest that there is oxygen supply and demand unbalance during THC and PLRP with venous bypass technique in pigs, and it is beneficial to monitor oxygen ladder during operation.
Animals↗
[Qualitative and quantitative studies on Chinese drug maidong].
OBJECTIVE: To explore a better approach to controlling the quality of Maidong. METHOD: The differences between Ophiopogon japonicus and the plants belonging to Liriope genus were identified by TLC. The total saponins in plants collected from different areas were determined by spectrophotometry, using HClO4 as the staining agent. RESULTS: The quantity of Maidong markedly varies with producing areas. CONCLUSION: This method is convenient and effective, and the MeOH extract of samples can be determined directly after reaction with HClO4 without preliminary treatment. The RSD was 0.75% (n = 5).
Chromatography, Thin Layer↗
[Antiviral action of combined use of rhizoma Polygoni cuspidati and radix Astragali on HSV-1 strain].
OBJECTIVE: The clinical action of combined use of Rhizoma Polygoni Cuspidati and Radix Astragali on HSV-1 was investigated with a view to developing a new antiviral drug. METHOD: The action was analyzed by way of plaque reduction assay and median-effect principle. RESULTS: In the HEp-2 cell system, if the combination ratio of Rhizoma Polygoni Cuspidati and Radix Astragali was 1(ED50):1(ED50) then, (1) In directly annihilating HSV-1 F strain, when the plaque reduction rate was 20%-80%, and the combination index was < 1.0, there was synergism. (2) In inhibiting the multiplication of HSV-1 F strain, when the plaque reduction rate was 20%-60%, and the combination index was < 1.0, there was also synergism. (3) In blockading HSV-1 F strain infection, when the plaque reduction rate was 20%-90% and the combination index was < 1.0, there was synergism. So this ratio of 1(ED50):1(ED50) should be the first choice for combination. CONCLUSION: The treatment index of the above two Chinese medicinal herbs equals 10(3), and the cytotoxicity is not potentiated, indicating that the combination is helpful as a virucide for HSV-1 F strain.
Antiviral Agents↗
[Observation of distortion product otoacoustic emissions in recovery course of sudden deafness].
OBJECTIVE: To realize the DPOAE resulting in sudden deafness and to investigate the changes of OAE in the recovery course of sudden deafness. METHOD: The basic characters of distortion product OAE (DPOAE) were studied in 60 ears of 30 cases with sudden deafness. The treatment and following-up were carried on too. RESULT: The incidence and amplitude of OAEs in the affected ears were lower than that of normal ears and normal group, and the threshold of DPOAE was higher too. In the recovery course the amplitude and threshold of DPOAE were improved with the restoration of auditory threshold, but the restoring rate (RR) of auditory threshold was higher. CONCLUSION: The DPOAE in sudden deafness implies a serious sensorineural hearing loss. In the recovery course, the amplitude and threshold of DPOAE is later than that of the pure-tone behavioral threshold, which implies that DPOAE is a sensitive and direct way in reflecting the function of cochlea.
Adult↗
The C-truncated delta-opioid receptor underwent agonist-dependent activation and desensitization.
The agonist-dependent activation and desensitization of a recombinant analog of delta-opioid receptor lacking the carboxyl-terminal (C-terminal) 31 residue peptide segment were discussed. The cDNA of the C-truncated delta-opioid receptor was created by polymerase chain reaction (PCR), stably expressed in Chinese hamster ovary cells and characterized by binding assay and function assay. Agonist [D-Pen2, D-Pen5]-enkephalin (DPDPE) stimulated the specific [35S]GTPgammaS binding to membrane fragments of cells expressing the C-truncated and the wild-type delta-opioid receptors in different levels dose-dependently. EC50 values of DPDPE on truncated and wild-types in stimulation were very similar. Agonist-dependent desensitization, which could be blocked by protein kinase inhibitor staurosporine (Stau), was observed after pretreating truncated receptors with 1 microM DPDPE for 10 min, the same as wild-types. The results reveal that the C-terminal of the delta-opioid receptor is not involved in controlling the G-protein activation and phosphorylation-related functional desensitization.
Animals↗
Cloning and expression of human UDP-glucuronosyltransferase (UGT) 1A8.
The mRNA expression of human UDP-glucuronosyltransferase 1A8 (UGT1A8) has been found in jejunum, ileum, and colon but not in liver. A cDNA with a complete UGT1A8 coding region was amplified from total human ileal RNA by reverse transcriptase-polymerase chain reaction and inserted into the mammalian expression vector, pcDNA3. Lysates of HK293 cells expressing UGT1A8 revealed the expression of a protein with a molecular mass of 56 kDa by Western blot analysis. Transiently expressed human UGT1A8 shows glucuronidation activities with coumarins, anthraquinones, flavonoids, phenolic compounds, catechol estrogens, 17-hydroxyandrogens, primary amines such as the carcinogen 4-aminobiphenyl, and certain opioids. This UGT may play an important role in the detoxification of xenobiotics in human intestine.
Catalysis↗
[Fluorescence-based semi-automated gene scan with microsatellite markers by multiplex PCR techniques].
OBJECTIVE: To develop a high output and low cost multiplex PCR approach to facilitating large scale gene scan and gene typing with microsatellite markers. METHODS: 5-15 pairs of primers of microsatellite loci were added in one single tube with 5ul reaction volume, containing 10 mmol/L Tris-HCl (pH8.3), 50 mmol/L KCl,0. 1mg/ml gelatin, 3.0 mmol/L MgCl2, 200micromol/L dNTPs (each), 0.25U Taq DNA polymerase, Taq Start antibody and DNA templates. PCR thermocycles were carried out on Perkin Elmer Gene Amp PCR System 9600 with touch-down algorithm (the annealing temperature was decreased by 0.5 C in each cycle) to meet the different demands of different primers. RESULTS: Up to 10-15 loci were labeled by different fluorescents or by the same fluorescent, but their PCR amplification fragments did not overlap in size. Almost all target microsatellite loci were successfully co-amplified in a 5 microliter reaction volume,electrophoresized and analyzed in a single gel lane with Perkin Elmer ABI 373A DNA sequencer, and 9 microsatellite loci were well genotyped. CONCLUSION: This high output and low cost genotyping protocol is applicable to gene mapping, human evolution and forensic analysis.
Genotype↗
Simple miniaturized gel system for DNA sequence analysis.
A simple miniaturized gel system suitable for DNA sequencing is described. Small ultrathin polyacrylamide gels are cast, eight or more at a time, using standard microscope slides. Gels, ready to use, can be stored for approximately 2 weeks. Gels are run horizontally in a standard mini-agarose gel apparatus. Typical run times are 6-8 min. A novel sample loading system permits volumes of standard sequencing reactions as small as 0.1 microl to be analyzed. Sequencing ladders were visualized using 35S-labeled DNA by autoradiography and by colorimetric detection. Band resolution compares favorably with that of large gels. The methods introduced here serve as a step toward the miniaturization of DNA sequencing and are amenable to automated sample loading and detection.
Autoradiography↗
Glucuronidation of catechol estrogens by expressed human UDP-glucuronosyltransferases (UGTs) 1A1, 1A3, and 2B7.
Catechol estrogens are major estrogen metabolites in mammals and are the most potent naturally occurring inhibitors of catecholamine metabolism. These estrogen compounds have been implicated in carcinogenic activity and the 4/2-hydroxyestradiol concentration has been shown to be elevated in neoplastic human mammary tissue compared to normal human breast tissue. Three human liver UDP-glucuronosyltransferases, UGT2B7, UGT1A1, and UGT1A3, have been shown to catalyze the glucuronidation of catechol estrogens and lead to their enhanced elimination via urine or bile. The present study was designed to study the kinetic interaction of expressed human UGT2B7(Y) or (H), UGT1A1, and UGT1A3 toward 2- and 4-hydroxycatechol estrogens. cDNAs encoding UGT2B7(Y) or (H), UGT1A1, and UGT1A3 were expressed in HK293 cells, and cell homogenates or membrane preparations were used to determine their glucuronidation ability. UGT2B7(Y) reacted with higher efficiency toward 4-hydroxyestrogenic catechols, whereas UGT1A1 and UGT1A3 showed higher activities toward 2-hydroxyestrogens. UGT2B7(H) catalyzed estrogen catechol glucuronidation with efficiencies similar to UGT2B7(Y). Flunitrazepam (FNZ), a competitive inhibitor of morphine glucuronidation in hepatic microsomes, competitively inhibited catechol estrogen glucuronidation catalyzed by UGT2B7(Y), UGT1A1, and UGT1A3. Buprenorphine, an opioid substrate that reacts at high efficiency with each of these UGTs, was also studied. FNZ competitively inhibited buprenorphine glucuronidation with UGT1A1 and UGT2B7 but had no inhibitory activity toward UGT1A3. This suggests that buprenorphine and 2-hydroxycatechol estrogens react with separate active sites of UGT1A3. A catecholamine, norepinephrine, did not inhibit UGT2B7(Y)-, UGT1A1-, and UGT1A3-catalyzed glucuronidation of catechol estrogens. These results also suggest that drug-endobiotic interactions are possible in humans and may have implication in carcinogenesis.
Estradiol↗
Comparison of the coat protein, movement protein and RNA polymerase gene sequences of Australian, Chinese, and American isolates of barely yellow dwarf virus transmitted by Rhopalosiphum padi.
Barely yellow dwarf luteovirus-GPV (BYDV-GPV) is a common problem in Chinese wheat crops but is unrecorded elsewhere. A defining characteristic of GPV is its capacity to be transmitted efficiently by both Schizaphis graminum and Rhopaloshiphum padi. This dual aphid species transmission contrasts with those of BYDV-RPV and BYDV-SGV, globally distributed viruses, which are efficiently transmitted only by Rhopaloshiphum padi and Schizaphis graminum respectively. The viral RNA sequences encoding the coat protein (22K) gene, the movement protein (17K) gene, the region surrounding the conserved GDD motif of the polymerase gene and the intergenic sequences between these genes were determined for GPV and an Australian isolate of BYDV-RPV (RPVa). In all three genes, the sequences of GPV and RPVa were more similar to those of an American isolate of BYDV-RPV (RPVu) than to any other luteovirus for which there is data available. RPVa and RPVu were very similar, especially their coat proteins which had 97% identity at the amino acid level. The coat protein of GPV had 76% and 78% amino acid identity with RPVa and RPVu respectively. The data suggest that RPVu and RPVa are correctly named as strains of the same serotype and that GPV is sufficiently different from either RPV strain to be considered a distinct BYDV type. The coat protein and movement protein genes of GPV are very dissimilar to SGV. The polymerase sequences of RPVu, RPVa and GPV show close affinities with those of the sobemo-like luteoviruses and little similarity with those of the carmo-like luteoviruses. The sequences of the coat proteins, movement proteins and the polymerase segments of BYDV serotypes, other than RPV and GPV, form a cluster that is separate from their counterpart sequences from dicot-infecting luteoviruses. The RPV and GPV isolates consistently fall within a dicot-infecting cluster. This suggests that RPV and GPV evolved from within this group of viruses. Since these other viruses all infect dicots it seems likely that their common ancestor infected a dicot and that RPV and GPV evolved from a virus that switched hosts from a dicot to a monocot.
Australia↗
Metabolism of endobiotics and xenobiotics by UDP-glucuronosyltransferase.
Explore the source record for details and available documents.
Animals↗
Measurement of cyclooxygenase inhibition in vivo: a study of two non-steroidal anti-inflammatory drugs in sheep.
The anti-inflammatory effects of the non-steroidal anti-inflammatory drugs phenylbutazone (PBZ) and flunixin meglumine (FM) and the relationship between the effects and drug concentration in vivo were studied using a subcutaneous tissue-cage model in sheep. Intracaveal injection of carrageenan induced prostaglandin (PG) E2 production in tissue-cage exudate (maximal concentration, 101 nM) with significant increases in white blood cell (WBC) numbers, skin temperature over the inflamed cage and exudate leukotriene B4 (LTB4) concentration (P < 0.05). Intravenous PBZ, 4.4 mg kg-1 produced mild inhibition of exudate PGE2 generation (10%), but greater inhibition of serum TXB2 (75.3%). The IC50 for TXB2 was 36.0 microM. Phenylbutazone did not alter effects on skin temperature, WBC numbers or exudate LTB4 concentrations. Intravenous FM, 1.1 mg kg-1, significantly inhibited carrageenan-induced exudate PGE2 formation (Emax, 100%, IC50, < 0.4 nM) and serum TXB2 generation (Emax, 100%, IC50, 17 nM) for up to 32 h. Flunixin meglumine significantly inhibited the rise in skin temperature but had a limited effect on exudate WBC. Phenylbutazone and FM have distinct effects on carrageenan-induced cyclooxygenase (COX-2) and platelet COX (COX-1). Flunixin meglumine was a more potent COX inhibitor than PBZ and was more selective for the inducible form of COX in vivo.
Animals↗
Pharmacokinetic studies of flunixin meglumine and phenylbutazone in plasma, exudate and transudate in sheep.
Flunixin meglumine (FM, 1.1 mg/kg) and phenylbutazone (PBZ, 4.4 mg/kg) were administered intravenously (i.v.) as a single dose to eight sheep prepared with subcutaneous (s.c.) tissue-cages in which an acute inflammatory reaction was stimulated with carrageenan. Pharmacokinetics of FM, PBZ and its active metabolite oxyphenbutazone (OPBZ) in plasma, exudate and transudate were investigated. Plasma kinetics showed that FM had an elimination half-life (t1/2beta) of 2.48 +/- 0.12 h and an area under the concentration - time curve (AUC) of 30.61 +/- 3.41 Lg/mL x h. Elimination of PBZ from plasma was slow (t1/2beta = 17.92 +/- 1.74 h, AUC = 968.04 +/- microg/mL x h). Both FM and PBZ distributed well into exudate and transudate although penetration was slow, indicated by maximal drug concentration (Cmax) for FM of 1.82 +/- 0.22 microg/mL at 5.50 +/- 0.73 h (exudate) and 1.58 +/- 0.30 microg/mL at 8.00 h (transudate), and Cmax for PBZ of 22.32 +/- 1.29 microg/mL at 9.50 +/- 0.73 h (exudate) and 22.07 +/- 1.57 microg/mL at 11.50 +/- 1.92 h (transudate), and a high mean tissue-cage fluids:plasma AUClast ratio obtained in the FM and PBZ groups (80-98%). These values are higher than previous reports in horses and calves using the same or higher dose rates. Elimination of FM and PBZ from exudate and transudate was slower than from plasma. Consequently the drug concentrations in plasma were initially higher and subsequently lower than in exudate and transudate.
Animals↗
[The LDL receptor activity of hepatocytes during cholesterol gallstone formation in rabbits].
In order to study the mechanism of cholesterol gallstone formation through rabbit model which was induced by high cholesterol diet, we investigated the LDL receptor activity of hepatocytes binding to 125I-LDL in different phases, namely 1, 2, 3 week group and 4 week, and in a control group besides. In this animal experiment, cholesterol gallstones were induced at 2 week, 3 week and 4 week groups in 4/10, 6/10, and 7/10 cases respectively. The Bmax values of LDL receptor of hepatocytes binding to 125I-LDL decreased significantly in 3 week and 4 week groups (vs 1 week and control groups, P < 0.05). The kd values became increased in 3 week and 4 week groups (vs 1 week and control group, P < 0.05), which suggested that the activity of LDL receptor decreased gradually. In conclusions owing to the intake of high cholesterol diet with the passage of time, the decreased activity of LDL receptor of hepatocytes would reduce the synthesis of bile acid.
Animals↗
[Ultrastructural pathologic research on the adult laryngeal papilloma].
In this paper, the ultrastructural features of laryngeal papillomas of 9 cases of adult patients were investigated by means of SEM. It showed that the polypoid surface of the papilloma is easily recognized; the surface cells are covered by microvilli of different size and shape; and the epithelium is bordered by an irregular and continuous basement membrane. In some areas, there is pseudopodium of basal cells stretching into connective tissue. The structure of interface between basement membrane and connective tissue varies with aggravation of tumor cell atypia. The significant variation of structural of basement membrane and semidesmosomes suggests the possibility of malignant change.
Aged↗