Biomedical subjects

D Liu

Publications and source records attributed to D Liu.

At least 505 records · Page 28Linked to original sources

PubMed1997

[The vascular basis of pedicled adrenal transposition and its usage in the treatment of Cushing's disease].

To treat Cushing's disease, we studied the length and exterior diameter of the inferior phrenic and superior adrenal artery and vein, and the reflow of the adrenal vein. The length and exterior diameter of those blood vessels were divided and measured by veiner calipor. Six patients with Cushing's disease were treated by pedicled adrenal transposition to the musculus of the back. The right inferior phrenic artery was 75-110 mm from the exterior edge of the vena cava to the distant branch of the superior adrenal artery, while the left inferior phrenic artery was 70-90 mm from the left edge of the aorta to the distant branch of the superior adrenal artery, both of which have veins to accompany them. The superior adrenal artery came from the inferior phrenic artery relatively common and was divided into six branches. The exterior diameter of the distal superior adrenal artery was 1.5-2.5 mm and could be freed for 40-80 mm. Lateral veins could complete the adrenal blood drainage after the left central adrenal vein was ligated. The transpositioned blood vessel pedicle consisted of the distant inferior phrenic artery and vein, the distant branches of the superior adrenal artery and vein. The patient who had received the transposition treatment had neither hypocortisolism nor recurrence after 4 to 35 months. The length of the inferior phrenic, superior adrenal gland vessels could content the remained adrenal gland to reach their transposition bed when freed. The pedicled adrenal transposition to the musculi is an ideal method in the treatment of Cushing's disease.

Adrenal Glands↗

PubMed1997

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

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

Blood Chemical Analysis↗

PubMed1997

[Reconstruction of larynx with epiglottis and strip muscular flap after extended partial laryngectomy with T3 category].

Fourty patients with T3 glottic cancer were treated by extended partial laryngectomy with reservation of epiglottis and posterior part of thyroid cartilage. The operative defect was covered by bilateral strip muscular flap to reconstruct the sphincter function of the glottis. The 3-year survival rate was 82.5% (32/40) and 5-year survival rate 72.9%(27/37). The function of the reconstructed laryngx was satisfactory. The authors believe that the strip muscular flap is a good material for the reconstruction of the new laryngx because of its good blood supply and wide-range repairing capability.

Adult↗

PubMed1997

Potassium channels on cardiomyocytes of selenium iodine deficiency rats and iodine deficiency rats.

Using diet control method to feed the weaning male Wistar rats with selenium and iodine deficiency Keshan endemic area food for 8 weeks to set up animal model. Singal channel recording in cell attached model was used to measure cardiac cell membrane potassium channel conductances, which coincide with the cardiac cell membrane potassium channel conductances in normal Wistar rats. The potassium channel conductance on selenium and iodine deficiency rat cardiac cell membrane is showing current-voltage increasing lineally in the range of clamping voltage 0 +/- 30 mV with channel conductance of 43.4 pS. The channel current does not increase depending on the clamping voltage that is showing the rectifying characteristic and the channel current amplitude can be augmented by added KIOa 5 mmol/L in bath solution. A kind of inward rectifying potassium channel activity was recorded, but this channel activity disappeared after lasting 6-10 minutes only. Then an inward rectifying potassium channel with the conductance of 14.2 pS was activated by KIOa 5 mmol/L introduced to bath solution. Both conductances are less than that of normal Wistar rats.

Animals↗

PubMed1997

[The effect of hypertonic saline solution on the rheology after burn-blast combined injury].

To study the effect of hypertonic saline solution on the rheology and putative mechanism, we investigated the changes of plasma viscosity, blood viscosity and reduced viscosity in dogs treated with hypertonic saline solution after burn-blast combined injury and observed the effect of hypertonic saline solution therapy on the viscoelastic property of erythrocyte membranes measured by micropippette aspiration technique in rats with burn. The results showed that the blood viscosity and reduced viscosity increased significantly in dogs after injury, and plasma viscosity also increased significantly at 24 h after injury. Elastic moduli and viscous coefficients of erythrocyte membranes increased obviously in rats after burn. The hypertonic saline solution therapy could significantly improve blood viscosity and reduced viscosity, but it did not significantly improve elastic moduli and viscous coefficients of erythrocyte membranes. These suggested that the hardness of erythrocyte membranes increased, the deform property of erythrocyte membranes decreased, and the blood rheology became worse after burn blast combined injury. Hypertonic saline solution therapy could significantly improve the blood rheology. The effect did not bear a significant relationship with the change of single biomechanics property of erythrocyte membranes. It might be related with other factors.

Animals↗

PubMed1997

[An inquiry on the normal value of Chinese' ENoG and the influencing factors].

The normal value of the ENoG of 172 facial nerves from 86 Chinese has been estimated with the method of regulating the strength of stimulating current. It showed that the CAPs of the Chinese' ENoG were of normal distribution. The mean of ampitudes was 3.94 +/- 1.02 mV. The coefficient of variation was 25.8%; The mean of latencies was 3.18 +/- 0.42 ms. The coefficient of variation was 13.2%. The variance from age to age, sex to sex and side to side were not significant. It was concluded that the interpretation of ENoG should be based on the fact that the CAP obtained from one certain subject was symmetrical between the opposite sides. The effecting factors which influenced the ENoG of normal facial nerve were also discussed in this paper.

Action Potentials↗

PubMed1997

[Studies on chemical structures of two iso-acetogenins from Annona reticulata].

Two annonaceous acetogenins: squamone (1) and isoannonareticin (2) have been isolated from the seeds of Annona reticulata L. (Annonaceae). 1 and 2 were shown to be mixtures of 2-epimers by the successful separation of their acetates with preparative TLC, giving: 2,4-cis-squamone diacetate (1a-1), 2,4-trans-squamone diacetate (1a-2), 2,4-cis-isoannonareticin diacetate (2a-1) and 2,4-trans-isoannonareticin diacetate (2a-2). The 2,4-cis-squamone (1-1) and 2,4-trans-isoannonareticin (2-1) are new annonaceous acetogenins. Their structures and relative stereochemistry were elucidated on the basis of spectral analysis (1H-1H COSY and NOE).

Drugs, Chinese Herbal↗

PubMed1997

[Transcription of antisense RNA of hepatitis B virus through retroviral mediated gene transfer].

To probe the ways by which the antisense gene of hepatitis B virus (HBV) can be transferred and transcripted in eukaryotic cells to inhibit HBV replication and expression. Two retroviral vectors that carried antisense gene of hepatitis B virus (HBV) PreC/C or PreS/S region were constructed. The HBV ayw PreC/C and PreS/S fragments were inserted into the vector pDO. R cloning site in the sense or antisense orientation and the recombinant retroviral vectors were then transfected into PA317 packaging cells by calcium phosphate coprecipitation, respectively. The stably transformed G418-resistant PA317 cells were selected and the recombinant retroviruses released from transfected G418-resistant PA317 cells were assayed by G418 selection method, using NIH 3T3 cells as target cells. Southern blot and RNA Dot blot analysis showed that the recombinant retroviral vector sequences were stably integrated into the chromosome of transfected PA317 cells and the antisense RNA of HBV PreS/S or PreC/C gene also transcripted in the transduced NIH 3T3 cells. These results suggested that antisense gene of HBV can be successfully transferred and transcripted in target cells through retroviral vector mediated gene transfer and the antisense retroviral vectors may be potentially useful for anti-HBV gene therapy.

Animals↗

PubMed1997

[Anti-virus effect of hepatocyte stimulating substance (HSS) on duck hepatitis B virus in vivo].

We used one day old Beijing ducklings infected by duck hepatitis B virus as experimental model to observe anti-virus effect of HSS. Beijing ducklings hatched within one day were injected intravenously with duck hepatitis B virus (DHBV). Positive DHBV-DNA in ducklings' sera were detected 7 days later. Serum samples were obtained from all ducklings before, during and after drug treatment at different times and stored at -70 degrees C. The collected samples were detected DHBV-DNA by dot-blot hybridization test at the same time. The therapeutic effects were evaluated by OD value of dot-blot and by the inhibitory rate of DHBV-DNA. The results showed that HSS (with 50 mg/kg/day and 200 mg/kg/day) were effective in inhibition of DHBV-DNA during and after drug treatment, especially in the HSS group of large dosage. The inhibitory effect appeared early and high dynamic. The inhibitory rate of DHBV-DNA during and after drug treatment were higher than the NS group (P < 0.05). No inhibitory effect was observed in NS group. The hepatic biopsy showed HSS groups had milder damage than NS group, indicating that the HSS could inhibit the replication of DHBV-DNA in Beijing ducklings.

Animals↗

PubMed1997

[The inhibitory effect of Chinese herb Phyllanthus on hepatitis B virus in vitro].

Seven preparations of different species of Chinese herb Phyllarthus with different formulations and additives were studied for their ability to inhibit hepatitis B virus DNA replication, that is the HBsAg and HBeAg expression in a HBV DNA-transfected cell line (2.2.15 cell). The results showed that all the drugs were effectively against HBV replication in vitro. Capsule 1 and tuo cha zhen zhu cao were found to be the most potent anti-HBV extracts of those examined. Both extracts decreased HBaAg expression by nearly 100% at the concentration of 500 mg/L without toxicity on cell growth. Southern blot showed that Capsule 1 inhibited HBV DNA replication in a dose-dependent manner. We observed further, that under similar dosage the drug inhibition to HBsAg and HBeAg expression was lower than that to HBV DNA replication, suggesting that the production of progeny virus particles not only were inhibited at the level of HBV DNA synthesis, but also was affected probably at the level of translation of viral mRNA.

Cell Line↗

PubMed1997

[The enrichment of polycyclic aromatic hydrocarbons in water samples by solid-phase extraction].

Solid-phase extraction (SPE) is an emerging chromatographic sample preparation technique. The novel extraction technique can reduce the time and volume of organic solvents required, and alleviate problems associated with the formation of emulsions as compared to conventional liquid-liquid extractions. This study was designed to demonstrate the utility of SPE for trace enrichment of polycyclic aromatic hydrocarbons (PAHs) in water samples. The results showed that dichloromethane and benzene are the preferred elution solvents for the adsorbed PAHs. The recoveries of PAHs with SPE are in the range of 87% to 102%. When the elution solvent is selected, the variation of recoveries as a function of the volume of elution solvent used can be determined. Meanwhile, further studies showed that recoveries become worse as the number of rings of PAH increased. The decrease of solubility and adsorption onto container surface may be responsible for bad recoveries. The addition of 20% (V/V) methanol or ethanol into the sample prior to spiking can greatly improve the recoveries of larger PAHs. Recoveries of 89%-108% can be obtained.

Polycyclic Aromatic Hydrocarbons↗

PubMed1997

[A simple method for analyzing insect pheromone at the nanogram level by coupling headspace adsorption and thermal desorption injection by gas chromatography with a packed syringe].

This paper describes a simple device for analysis of insect pheromones by coupling headspace adsorption and direct nonsolvent thermal desorption injection by gas chromatography (GC). A microsyringe packed with Porapak Q as the adsorbent was mounted in the airway for enriching and collecting pheromones. After collection the microsyringe was inserted into a thermal desorption device which was coupled with a GC inlet port. The pheromone desorbed from the adsorbent was condensed on the cold head of the GC column and injected into the column by quickly increasing the temperature of the column oven. The synthetic compounds of insect pheromones, E-7-dodecyl acetate (E-7-DA) and Z-5, E-7-dodecadienyl acetate (Z-5, E-7-DDA), were used to determine the recovery of the method and to evaluate the utility of this device for GC analysis of insect pheromones at the nanogram level. The results demonstrated the potentials of this device for GC analysis of volatile components both on packed columns and capillary columns. The advantage of headspace collection is that it avoids interference from non-volatile contaminants and the advantage of nonsolvent thermal desorption injection is to avoid the loss of pheromone while concentrating the eluted solution. The reported method combines these two advantages. The author also discusses the ways to further improve the method.

Animals↗

PubMed1997

Lower eyelid tightening: a comparative study.

Tightening of the lower eyelid is often performed as an adjunct to various lower lid procedures, and many techniques are available. Herein the author describes a simple and effective surgical technique and compares its failure rate with that of full-thickness pentagonal lid resection and lateral tarsal strip technique. Over a 7-year period, the author has used this procedure on 121 patients (153 eyelids) requiring horizontal tightening of the lower eyelid. The average follow-up period is 19 months and the results have been excellent. Complications included three overcorrections, one undercorrection, three suture abscesses, two exposed sutures, and two suture breakages. The most common complication was a transient point tenderness over the orbital rim lasting 2 to 4 weeks. Comparison of these results with those obtained in 44 other patients (54 eyelids) whose lower eyelids were tightened with either the pentagonal lid resection or the lateral tarsal strip technique showed this procedure to be just as effective and versatile yet much easier to perform.

Aged↗

PubMed1997

Phosphorylation of beta-catenin and epidermal growth factor receptor by intestinal trefoil factor.

Intestinal trefoil factor (TFF3) is a member of the trefoil family of peptides, which are constitutively expressed in the gastrointestinal tract. TFF3 has been shown to promote migration of intestinal epithelial cells in vitro and to enhance epithelial restitution in vivo. In the present study, we show that the stimulatory effect of TFF3 on the migration of HT29 colonic carcinoma cells requires the perturbation of E-cadherin function, a calcium-dependent cell-cell adhesion molecule in epithelia. A rapid (< 1 minute) and specific tyrosine phosphorylation of beta-catenin and epidermal growth factor receptor was detected in cells treated with recombinant rat TFF3. No phosphorylation of E-cadherin or alpha-catenin was detected. Tyrosine phosphorylation of beta-catenin was associated with reduced membranous E-cadherin expression, perturbation of intercellular adhesion, and promotion of cell motility. These results suggest that TFF3 enhances cell migration through modulation of E-cadherin/catenin complex function. Tyrosine phosphorylation of beta-catenin and epidermal growth factor receptor seems to be involved in this process.

Animals↗

PubMed1997

[Transfection and expression of human thrombopoietin cDNA for treatment of thrombocytopenia in mice].

OBJECTIVES: To explore that COS-7 cells efficiently transfected with human thrombopoietin (hTPO) cDNA from fetal liver and hTPO potentially treated carboplatin-induced thrombocytopenia in mice. METHODS: Using molecular cloning technique, expression vectors PCIneo under the control of SV40 early. Applying liprofectin mediating method, recombinant plasmids PCIneo-hTPO were transfected into COS-7 cells in addition to effect of G418. After hTPO cDNA and mRNA in colony COS-7 cells were respectively identified by PCR-Southern and dot blot, hTPO was analysed with sandwich ELISA and administrated intraperitoneally to mice with thrombocytopenia. RESULTS: COS-7 cells transfected with constructed PCIneo-hTPO expressed and secreted hTPO up to 48.28 ng/ml in the supernatant. We kinetically observed that the number of megakaryocyte-colony-forming unit (CFU-MK) in bone marrow enhanced to threefold (P < 0.01), especially the number of small CFU-MK, accompanied by an increased mean megakaryocyte volume (P < 0.01) and circulating platelets returned to a normal level (80 +/- 26, x 10(9)/L, P < 0.01) in peripheral blood. CONCLUSION: Recombinant PCIneo-hTPO can efficiently be transfected into COS-7 cells and hTPO is an effective cytokine for treating carboplatin-induced thrombocytopenia in mice.

Animals↗

PubMed1997

[Comparison of stature growth curves in children and adolescents].

Growth charts of height in Chinese children and adolescents (excluding Taiwan and Hong Kong) in the 1980s and 1990s were fitted to JPA2 model to study their growth and developmental characteristics and their future trend and to compare them with the criteria for growth in the developed countries and areas. Results showed that fitted growth curves were comparable. The difference in body height of children in cities during puberty period was the most significant during the 1980s. Body height of boys and girls aged over seven to maturity period in Beijing during the 1990s was higher than that in Hong Kong and Japan, and reached basically the criteria set by the National Center for Health Statistics (NCHS), United States, but body height of adults was still three to four centimeters lower than that in criteria set by NCHS. Body height in adolescents in Beijing was kept in stable as compared with that in the 1980s.

Adolescent↗

PubMed1997

[Pedicled thoraco-abdominal skin flap applied in early repair of deep ulcer of upper extremity resulting from snake-bite injury].

The ulcer resulting from snake-bite injury was characterized by deep and wide tissue necrosis and secondary infection. The patient was at high risk of loss of function of his extremity. From 1989 to 1996, 16 cases with deep ulcer of the upper extremity resulting from snake-bite injury were treated with different types of axial thoraco-abdominal skin flaps, depending on the location of the ulcer. Thoraco-umbilical skin flap was used in 2 cases, lateral thoracoabdominal skin flap in 1 case, iliolumbar skin flaps in 5 cases, lower abdominal skin flaps in 6 cases, lower abdominal divided foliated skin flap in 1 case and Y-shaped hypogastric skin flap in 1 case. Reparative operation was carried out within 3 weeks after injury and primary repair were undertaken in 6 of them. The pedicles were divided in 17 to 24 days after operation. Twelve flaps survived. Three of the 6 flaps had mild signs of inflammation which disappeared after administration of antibiotics. One had necrosis of the distal part of the flap, and was healed with split skin graft. This type of skin flap was an ideal method for the treatment of snake-bite injury of the upper extremity.

Adolescent↗

PubMed1996

Source of transport site asymmetry in the band 3 anion exchange protein determined by NMR measurements of external Cl- affinity.

Flux measurements indicate that a far greater number of unloaded band 3 anion transport sites face the cytoplasm than face the external medium, but the reason for this striking asymmetry has remained obscure. To resolve this question, we have measured the apparent Cl- affinity of the transport site of human red blood cell band 3 protein under various conditions by analyzing the 35Cl NMR free induction decay (FID). The [Cl-] that half-saturates the transport sites with [Cli] = [Clo] (K1/2) in RBC membranes (ghosts) is 46 +/- 5 mM at 0 degree C, while the Ko1/2 (for half-saturation with [Clo] at constant [Cli]) of intact cells is 3.2 +/- 2.1 mM. When cells were pretreated with EM, an inhibitor of band 3 anion exchange that does not prevent Cl- binding to the external transport site, K1/2 and Ko1/2 are 41 +/- 14 and 46 +/- 12 mM, respectively. The EM-induced increase in Ko1/2 with little change in K1/2 can be most simply interpreted as meaning that EM abolishes the effects of the translocation rate constants on Ko1/2 so that Ko1/2 and K1/2 of EM-treated cells now both reflect the true dissociation constant for binding of Cl- to the external transport site, Ko. The fact that Ko for a slowly transported anion, iodide, is nearly the same in EM-treated as in control cells indicates that EM does not significantly affect Ko for chloride. Our results indicate that the true dissociation constants for Cl- at the inside and outside are very similar but that the rate constant for inward translocation is much larger than that for outward translocation. For this reason, both unloaded and Cl-loaded transport sites are asymmetrically oriented toward the inside, and Ko1/2 (in untreated cells) is much lower than Ko.

Anion Exchange Protein 1, Erythrocyte↗