Biomedical subjects

B Liu

Publications and source records attributed to B Liu.

At least 451 records · Page 25Linked to original sources

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

[DNA polymorphisms of apolipoprotein A I gene in Chinese endogenous hypertriglyceridemics].

The restriction fragment length polymorphisms (RFLPs) of apolipoprotein(apo) A I gene were studied using polymerase chain reaction (PCR) in 69 endogenous hypertriglyceridemics (HTG) and 74 healthy subjects from a population of Chinese Han nationality in Chengdu area. The loci studied included Msp 1 within intron 3 of the apo A I gene; Xmn I, 5' to the apo A I gene; and Pst I, 3' to the apo A I gene. The results showed that both in HTG group and control group M1, X1 and P1 alleles were the major alleles and homozyous M1M1, X1X1 and P1P1 genotypes were the most frequent ones. The frequencies of rare M2 and X2 alleles in Chinese were significantly higher than those in European Caucasians (0.293 vs 0.111, P < 0.0006, 0.286 vs 0.130, P < 0.004), but no differences were found in the frequency of rare P2 allele (0.071 vs 0.046, P > 0.05). The frequency of rare M2 tended to increase in the HTG group when compared with the control group (0.353 vs 0.275, P > 0.05). Both in the HTG group and control group, subjects with genotype M2M2 had a higher serum mean concentration of TC, apo C II and higher serum TG/HDL-C ratio compared with the subjects with the genotypes M1M1 and M1M2 (P = 0.05, P < 0.03, P < 0.04), and the serum TG, apo C II and apo E levels had a tendency to increase. The subjects with the genotypes P1P2 and P2P2 had a higher serum apo A II levels compared with the subjects with the genotype P1P1 (P < 0.04). The data show that the only Msp I RFLP within the intron 3 of apo A I gene is associated with endogenous hypertriglyceridemia to some extent in Chinese population.

Adult↗

PubMed1997

[Oxidative modification of serum LDL, VLDL and HDL induced by fed on high cholesterol diet in vivo in rabbits].

Many lines of evidence suggest that LDL is oxidized in vivo and that ox-LDL is present in the artery wall. But the oxidation of VLDL and HDL in vivo has not been reported yet. A study on effects of high cholesterol diet on oxidative modification of LDL, VLDL and HDL in rabbits was made. The control group (n = 8) was fed on routine diet, and the experimental group (n = 8) on high cholesterol diet (routine diet supplemented with 5% lard, and 0.5 g cholesterol a day for each rabbit) for 12 weeks. The serum LDL, VLDL and HDL were isolated by the density gradient ultra centrifugation. The oxidative modification of LDL, VLDL and HDL was identified by agarose gel electrophoresis, absorbance at 234 nm and fluorescence of TBARS. The results showed that serum TC, TG and TBARS in the experimental group were significantly higher than these of the control group (P < 0.01). The electrophoretic mobility of LDL, VLDL and HDL was increased, and absorbance at 234 nm and TBARS of LDL, VLDL and HDL in the experimental group were significantly higher than these of the control group (P < 0.01). These results suggest that not only LDL but also VLDL and HDL were oxidatively modified in vivo in rabbits after fed on high cholesterol diet.

Animals↗

PubMed1997

[Serum apolipoprotein C II, C III and E levels in 437 male healthy subjects aged 40-70 in Chengdu area].

Apolipoprotein (apo) C II, C III and E levels of 437 male healthy subjects aged 40-70 [with fasting serum triglyceride (TG levels < 2.26 mmol/L, total cholesterol (TC) levels < 6.21 mmol/L and plasma glucose levels < 6.10 mmol/L] in Changdu area were determined by radial immunodiffusion assay (RID). The results showed that the concentrations of apoC II, C III and E were 41.6 +/- 13.1, 112.8 +/- 31.0 and 38.7 +/- 8.2 mg/L (mean +/- s) respectively. No difference in the serum levels of apoC II, C III and E was noted between the men of different ages. The results of the linear correlation showed that there was a positive correlation of apoC II, C III, E with TG, TC, LDL-C; of apoC II, C III with BMI; and of apoE with ages.

Adult↗

PubMed1997

[The serum lipid and apolipoprotein levels of middle-aged male hyperlipidemics in Chengdu district].

It has been evidenced that cardiovascular diseases (CVD) relate with many risk factors and serum lipids play and essential role in the development of CVD. In order to further study hyperlipidemia (HL) in the middle-aged males, we analysed the body mass index (BMI), fast blood sugar (FBS), serum lipids and apolipoproteins A I, A II, B100, C II, C III and E in 223 male HL patients aged 41-60 and 349 normal male subjects who matched the HL patients in age. The result showed that the increase of serum triglycerids (TG), was as might be expected, the major characteristic of the middle-aged male HL patients in Chengdu District. Besides the serum lipid and apolipoprotein B100, C II, C III and E levels, the BMI and FBS levels in the IIb, IV and V types of HL patients were significantly higher than those in the normal subjects. It also showed that in TG increased patients the increased percentages of serum lipids were significantly higher than those of apolipoproteins. The age distribution in HL patients revealed that only 25% of the HL patients were between 41 to 50 years old, while 50% in the 56-60 year-old group. The relationship between apolipoprotein levels and serum lipid metabolism is also discussed. The results suggest that the 51-60 year-old males should pay attention to diet and increase physical activities to reduce incidence of HL which is directly associated with CVD.

Adult↗

PubMed1997

[Relation of serum apolipoprotein B100 levels to lipids and apolipoproteins A I, A II, C II, C III and E levels in the middle and old age normal males in Chengdu area].

This study was conducted in 438 normal men aged 40-70. The age groups were: 40-44, 45-49, 50-54, 55-59, 60-64, and 65-70. The results showed that the serum apolipoproteins levels (mean+/- s, mg/L) were: B100 levels 742.5 +/- 165.8, A I 1301.2 +/- 219.9, A II 299.4 +/- 49.0, C II 42.7 +/- 21.4, C III 113.3 +/- 34.0 and E 38.7 +/- 8.2. The levels of serum apoB100 increased with age. The serum apoB100 levels in the 5th and 6th age groups were significantly higher as compared with the groups 1, 2, 3 and 4 (P < 0.05 and P < 0.05). The fasting serum mean TG (1.39 +/- 0.45 mmol/L), TC(4.79 +/- 0.82 mmol/L) and LDC-C(1.62 +/- 0.40 mmol/L levels in the groups 5 and 6 were significantly higher as compared with the groups 1, 2, 3 and 4 (P < 0.01). Serum apoC II, C III and E levels were significantly increased in the groups 5, 6 (P < 0.05). The correlation analysis indicated that there was a positive correlation of apoB100 with serum TG, TC, LDL-C, apoC II, C III and E respectively (P < 0.01); and a negative correlation with HDL-C levels (r = 0.1312); and apoB100 correlated negatively with apoA I (r = -0.0706). The results suggest that serum TG, TC, LDL-C, apoC II, C III and E are the main factors related with the serum apoB100 levels.

Adult↗

PubMed1997

[Quantitation of human apolipoprotein B100 by immunoturbidimetric assay].

An immunoturbidimetric assay(ITA) for quantification of human serum apolipoprotein B100 (apoB100) was developed. The assay is sensitive, rapid, specific, easily automatic and thus convenient for routine work. The minimu measurable concentration of apoB100 was 3.1 micrograms in each assay. The standard curve with a working range of 0.34-1.79 g/L was plotted. The between and within assay coefficients of variation were 1.13%-3.48% and 2.91%-4.48% respectively. The recovery was 99.23% +/- 3.57%. The mean serum concentration of apoB100 in 100 normal subjects was 0.821 +/- 0.165 g/L. The correlation coefficient of RID for apoB100 to ITA was 0.8626(P < 0.001).

Apolipoprotein B-100↗

PubMed1997

[Improvements of laryngectomy cricopharyngeal anastomosis laryngeal reconstruction (report of 27 cases)].

To alleviate the deglutition and increase decannulation rate in Arslan's operation, 27 patients who had undergone laryngectomy cricopharyngeal anastomosis reconstruction from 1989 to 1995 in our hospital were reported. There were T1bN0 8 cases, T2N0 17 cases, T3N0 2 cases according to UICC staging in 1987. All lesions located in vocale cords bilaterally. On the side of the mild lesion, over half of the vocale cord was invaded. The main points of surgical procedure were that the epiglottic and cricoid cartilage were restored. Hyoid bone and arytenoid cartilages were resected and cricoid cartilage anastomosis with the base of the tongue and submental muscles. Phonation was restored in all postoperative patients. Deglutition was alleviated significantly. Decannulation rate was 92.6% (25/27). The follow-up period of 14 cases was over 3 years. Of the 14 cases, 1 died. The 3 years survival rate was 92.86% (13/14). The follow-up period of 6 cases was over 5 years. Of the 6 cases, 1 was lost, the 5 years survival rate was 83.33% (5/6). The operation has great effects on alleviating deglutition and increasing decannulation rate.

Adult↗

PubMed1997

[The relation between trace element selenium and osseointegration of titanium implants].

Titanium implants were placed bilaterally in the proximal tibia of thirty-six adult male rabbits to demonstrate the relation between trace element selenium and titanium implants osseointegration. The animals were randomly divided into the control group and the selenium adding group. There were eighteen animals in each group. In experimental group, Na2SeO3 10 micrograms/kg body weight was given intramuscularly everyday for 6 days postoperatively, Measurement of trace element selenium contents, histologic findings and mechanical testing were applied to evaluate the effect. The results showed that trace element selenium contents of bones around implants were positively related to the strength of the implant fixation. Selenium could obviously speed up the formation of implant osseointegration and significantly improve the strength of the implants fixation compared with the control group at 1 week and 4 weeks after implantation.

Animals↗

PubMed1997

A comparative study of gut suture, human amnion collagen, bovine skin collagen and Vicryl suture implants in rats.

This study compares the persistence and histological characteristics of gut suture with those of human amnion collagen, bovine collagen, and Vicryl suture implants in rats. Gut suture and human amnion collagen more resembled living tissue than did bovine collagen and were characterized by their cellularity and the presence of numerous capillaries. The Vicryl suture implants were quickly absorbed. Picrosirius polarization revealed the synthesis of host collagen by rat fibroblasts which immigrated into the gut suture and human amnion collagen implants. The authors suggest the potential of gut suture as a soft tissue substitute to improve linear skin contour deficits.

Absorbable Implants↗

PubMed1997

Characteristic of facial muscle and efferent nerve on physiology and anatomy.

OBJECTIVE: To study the specialty of orbicularis oculi muscles, nerves and oris muscles, nerves and mechanism of difference of facial muscular injury in facial paralysis deeply. METHODS: The conductive velocity of the efferent nerves of orbicularis oculi and oris muscles of the health human beings and guinea pigs is measured with electromyogram (EMG) apparatus. RESULTS: The conductive velocity of orbicularis oculi nerve is quicker and oris muscles are controlled by facial nerves on both sides. Measuring the threshold of Strength-Duration (S-D) curves of the motor point of orbicularis oculi and oris muscles shows the threshold of the former is lower. Measuring the diameter of orbicularis oculi and oris nerve fibers on the guinea pigs and rabbits shows the diameter of orbicularis oculi nerve fiber is bigger. The area of secondary synapse space of orbicularis oculi motor end plate is larger than that of oris under scanning electron microscope. CONCLUSIONS: Orbicularis oculi muscles, orbicularis oculi nerves and oris muscles, oris nerves all have their own characteristic on physiology and anatomy. It elucidated the mechanism that orbicularis oculi muscle is easy to be injured.

Action Potentials↗

PubMed1997

[Establishment of immediate implant animal model in mongrel dog's fresh extraction socket].

The purpose of the study was to establish the animal models which had clinical characteristics in bone defect sizes around immediate implants. The mesial region of dogs' fresh extraction sockets were made with 3 mm x 3 mm x 5 mm size bone defects around implants with a round bur, then observed their osseous changes at 2 weeks, 4 weeks, 8 weeks, 12 weeks with and without demineralized freeze-dried bone allograft (DFDBA) filled. The results showed that the bone defects in DFDBA grafted group were substituted by new bone, but the defects in ungrafted group were only substituted to 3/5. Such animal models had the advantages of simple preparations and similar clinical characteristics, so they were beneficial to investigation of the immediate implantation.

Animals↗

PubMed1997

[The influence of basement membrane matrix on the attachment of human gingival epithelial cell to titanium: a scanning electron microscopic study].

In order to investigate the factors which could enhance the integrity of the biological seal between implant and epithelial cells, basement membrane matrigel was coated on the surface of smooth pure titanium. SEM observations showed that the spreading of primary cultured human gingival epithelial cells on Matrigel coated titanium surface was better than that of control groups on the third and the sixth day. This result suggests that the attachment of human gingival epithelial cells to titanium can be enhanced by the basement membrane matrigel.

Biocompatible Materials↗

PubMed1997

[Tolerance limit of human upper extremity with arm restraint plate on eject seat to simulated aerodynamic loads].

To obtain tolerance limit of human upper extremity with arm restraint plate on eject seat to windblast, impact was applied to the upper extremity of 13 human corpses and 7 living monkeys by a spring driven impact device. Relationship between impact load, moment of elbow joints and arm injuries with arm restraint plate were studied. Relationship between biomechanical characteristic curve of human elbow joint and clinical injuries was obtained. The results indicated that tolerance limit of human upper arm is higher than forearm. Safety limit of human anterior arm to simulated aerodynamic load is 1.26 kN.

Aerospace Medicine↗

PubMed1997

[Tolerance of human and rhesus monkey elbow joints].

In order to study tolerance transfer relationships between human and rhesus monkey elbow joints, torsional and bending tests were conducted on human and rhesus monkey elbow joints under the same condition, and the tolerance transfer relationships between their elbow joints were obtained by comparing and analysing their biomechanical properties. The results show that the mean load transfer ratios between human and rhesus monkey elbow joints were 3.65 and 4.28 for torsional and bending injury respectively.

Animals↗

PubMed1997

[A comparative study on chemical constituents in different processed products of Dioscorea opposita].

The quantitative comparisons of Water-soluble extract, alcohol-soluble extract and allantoin in crude and three processed products of Dioscorea opposita is carried out by the method recorded in Pharmacopoeia and TLCS respectively. As a result, the changes of water-soluble extract and alcohol-soluble extract during the four samples are similar. It is the hightest in the processed product stir-fried with soil and lowest in the crude. But for allantoin, it is the highest in the processed product stir-fried with wheat bran and lowest in that stir-fried with no material. It is suggested that the contents between water-soluble extract, alcohol-soluble extract and allantoin are not interrelated. It shall be considered to increase the content of allantoin as a quality control index to control the quality of the processed products.

Allantoin↗

PubMed1997

[Content determination of total coumarin of qian-hu].

The total content of coumarin in Qian-Hu was determined by UV spectrometry. The 25 samples which derived from different places of production were included eleven varieties. The results were found to have max = 322 nm, 99.18% of recovery rate and 2.08% of RSD.

Coumarins↗

PubMed1997

[Studies on the pharmacognosy of Cortex Illicii and its adulterants].

The traditional Chinese Medicine Cortex Illicii and its adulterants were studied on textual identification, botanical origin, morphological and histological characters. The TLC and UV spertra methods were established to separate and estimate Difengpin, Magnolol and beta-sitosterol in Cortex Illicii and its products.

Chromatography, Thin Layer↗