Biomedical subjects

Z Liu

Publications and source records attributed to Z Liu.

At least 307 records · Page 17Linked to original sources

PubMed2001

[Ultrasonic measurement of fetal liver length and its clinical significance].

OBJECTIVE: To establish the normal growth velocity of fetal liver length and compare them with those of intrauterine growth retardation, pregnant diabetes and maternal-fetal blood types imcompatible. METHOD: Three hundred and five normal pregnant women and 24, 10, 16 pathological pregnant women of intrauterine growth retardation (IUGR), gestational diabetes and maternal-fetal blood types incompatible respectively had ultrasonographic measurement of fetal liver length at 18 to 42 weeks' gestation. RESULTS: Normal fetal liver length has a linear relation to gestational age, and showed a significantly rapid increase after 28th week with a growth rate of 1.76 mm per week, and 1.00 mm per week before 28th week (P < 0.05). The growth rate of IUGR group before and after therapy were 1.19 mm and 1.23 mm per week, significantly lower than those of normal group (P < 0.05). The growth rate of pregnant diabetes group before and after therapy were 1.63 mm and 1.63 mm per week, no statistical significance with normal group (P > 0.05). The growth rate of maternal-fetal blood types incompatible group before therapy was 1.98 mm, showed no difference with normal group (P > 0.05), but after therapy, the growth rate of fetal liver was 1.38 mm per week, significantly lower than normal group (P < 0.05). CONCLUSION: Dynamic measurement of fetal liver length can help us to understand whether the fetus grow well in uterus and whether the treatments are effective.

Female↗

PubMed2001

Study on action of acupuncture on ventromedial nucleus of hypothalamus in obese rats.

Effects of acupuncture on the spontaneous discharge of nerve cells and levels of monoamine neurotransmitters in ventromedial nucleus of hypothalamus (VMH) of the obese rats were investigated. Results indicated that the levels of tyrosine (Tyr) and dopamine (DA) were lowered, the levels of 5-hydroxytryptamine (5-HT) and 5-hydoxyindole acetic acid (5-HIAA) increased, and the frequency of the spontaneous discharge of nerve cells in VMH lowered in the obese rat group as compared with the normal group. When acupuncture obtained the effect of weight reduction, the frequency of spontaneous discharges of nerve cells in VMH were markedly increased, and the levels of Tyr, DA and tryptamine (Typ) and 5-HT/5-HIAA ratio elevated, and the 5-HT level lowered. It is suggested that the virtuous regulative action of acupuncture on VMH might be one of the key factors in acupuncture for weight reduction.

Acupuncture↗

PubMed2001

The distribution and significance of renal infiltrating cells in patients with diffuse crescentic glomerulonephritis.

OBJECTIVE: To study the significance and distribution of renal infiltrating cells, including monocytes (CD68+ cells), proliferative cell nuclear antigen positive cells (PCNA+ cells), CD4+ and CD8+ cells in diffuse crescent glomerulonephritis (DCGN). METHODS: Fifty-six patients with DCGN were studied, including 10 cases of anti-glomerular basement membrane (GBM)--type I DCGN, 26 immune complex--type II DCGN, and 20 cases of pauci-immune--type III DCGN. Glomerular and interstitial infiltrates of CD68+ and PCNA+ cells, and interstitial infiltrates of CD4+ and CD8+ cells were detected by using four-layer PAP methods. RESULTS: There was a significant increase of renal infiltrating CD68+, PCNA+, CD4+ and CD8+ cells in patients with DCGN compared with that in normal controls. In patients with type I DCGN, there was a higher number of renal infiltrating CD68+ and PCNA+ cells than that in patients with type II and III DCGN. A glomerular infiltrates of CD68+ and PCNA+ cells correlated with the interstitial infiltrates of CD4+ cells in type I or III DCGN patients. In lupus DCGN patients, the numbers of renal infiltrating CD68+ and PCNA+ cells were similar to vasculitis or type III DCGN patients. CONCLUSION: These findings demonstrate that the renal infiltrates of CD68+ and PCNA+ cells play an important role in patients with DCGN, that the infiltrates of CD4+ cells correlate with the infiltrates of CD68+ and PCNA+ cells may be an active marker of DCGN, and that cell-mediated immunity may contribute to crescent formation in lupus DCGN patients.

Adolescent↗

PubMed2001

Cyclosporin A treatment for idiopathic membranous nephropathy.

OBJECTIVE: To evaluate the efficacy of cyclosporin A (CSA) in the treatment of idiopathic membranous nephropathy (IMN), a prospective controlled clinical study was performed. METHODS: This study included a group of 30 IMN patients, among them 15 were treated with CSA and 15 with captopril (CAP). The diagnosis of IMN was made with exclusion of secondary forms of membranous nephropathy by extensive clinical and pathological studies. No patients received steroids or cytotoxic agents for six months prior to enrollment. In the CSA group, CSA was given at an initial dosage of 5 mg.kg-1.d-1, gradually tailed off over the first three months and maintained at 2 mg.kg-1.d-1 for 12 months. In the CAP group, CAP was given at a dosage of 37.5 mg/day. RESULTS: In the first three months, 6 (6/15) complete remissions (CR) and 2 (2/15) partial remissions (PR) were observed in the CSA group while only 2 (2/15) PRs were observed in the CAP group. Before the end of the 15-months, 8 patients in the CSA group experienced CR and 4 patients experienced PR. One CR patient relapsed as the dosage of CSA was reduced, so 7 patients remained in CR at the end of the first 15-months. No additional CR or PR was observed in the CAP group during late follow-up. At the last visit (an average follow-up time of 44 months) in the CSA-group, another 2 CR patients had relapsed and 1 CR patient shifted to PR after stopping the CSA treatment, so 4 CR and 5 PR remained in the CSA group. In the CAP group, 3 spontaneous CRs occurred beyond 1.5 year's follow-up, with 3 CR and 2 PR at the last visit. No difference was found between the averages of the initial and the last serum creatinine levels in either group. No serious adverse effects were found during CSA treatment. Re-biopsy data of three patients responsive to CSA treatment showed that no pathological improvement of glomerular basement membrane was observed, even in cases at remission. Tubulointerstitial fibrosis was found in 1 relapsed CR patient, whose serum creatinine increased above the normal range, but not in the other 2 patients whose serum creatinine remained in the normal range. CONCLUSIONS: CSA therapy at a dosage of 5 mg.kg-1.d-1 is effective in inducing remission of nephrotic syndrome in adult IMN patients within three months, with a response rate of 80%. A relatively high rate of relapse (50%) was observed within 2 years after the withdrawal of CSA treatment.

Adult↗

PubMed2001

Gene polymorphism in IL-1 receptor antagonist affects its production by monocytes in IgA nephropathy and Henoch-Schonlein nephritis.

OBJECTIVE: To define the functional significance of IL-1 receptor antagonist (IL-1ra) gene polymorphism and to investigate, the production of IL-1ra by monocytes from individuals with different genotypes of IL-1. METHODS: The genotype of IL-1ra was detected by polymerase chain reaction (PCR). Peripheral monocytes obtained from patients with immunoglobin A nephropathy (IgAN), Henoch-Schonlein purpura nephritis (HSPN) and normal subjects were matched in sex and age between the IL1RN-2 allele carriers and non-carriers. The secretion of IL-1ra, IL-1 alpha and IL-1 beta in the supernatant of GM-CSF (10 ng/ml) treated and untreated monocytes were measured by ELISA. RESULTS: The secretion of IL-1ra by monocytes stimulated with GM-CSF was significantly higher in the IL1RN-2 allele non-carriers than those of carriers both in IgAN (21.55 +/- 3.08 vs 13.85 +/- 2.24 ng/ml, P < 0.001) and HSPN (23.72 +/- 6.68 vs 12.67 +/- 2.24 ng/ml, P < 0.01) as well as in normal controls (20.29 +/- 1.45 vs 10.51 +/- 2.3 ng/ml, P < 0.001). All showed no significant differences in monocyte secretion of IL-1 alpha and IL-1 beta by GM-CSF stimulation between the IL1RN-2 allele carriers and non-carriers. CONCLUSIONS: These results indicate that a functional correlation of the IL1RN-2 allele and IL-1ra production is present in patients with IgAN and HSPN. This gene polymorphism control of IL-1ra production may contribute to the variety of clinical responses to inflammatory stimulation in individuals with different genotype of IL-1ra.

DNA↗

PubMed2001

[Expression of Fas on monocytes and the level of plasma soluble FasL in patients with chronic renal failure].

OBJECTIVE: The dysfunction of monocytes in uremic patients has been demonstrated to be associated with monocyte accelerated apoptosis. The study was conducted toelucidate the mechanisms by which monocyte apoptosis was induced. METHODS: Seven non-dialyzed chronic uremic patients and 18 hemodialysis (HD) patients were enrolled in the study. Fifteen healthy volunteers were selected as controls. The expression of Fas and Fas ligand (FasL) was examined by immunofluorescent staining and flow cytometer analysis. The levels of soluble FasL (sFasL) in plasma were analyzed by enzyme-linked immunosorbent assay (ELISA). The percentage of apoptotic cells in monocytes cultured in vitro with recombinant human FasL (rHu-FasL) was quantitated by DNA content analysis after extraction of the degraded DNA. Monocyte survival rate was analyzed by 5-diphenyl tetrazolium bromide (MTT) staining. RESULTS: Expression of Fas on monocytes was significantly higher in uremic and HD patients than that in healthy subjects. Higher levels of Fas expression were demonstrated on monocytes from HD as patients compared with those from non-dialyzed patients. There was no difference in monocyte Fas expression between pre- and post-dialysis session and between patients using polysulfone and cellulose dialyzer. There was no detectable FasL expression on monocytes from both uremic patients and healthy controls. Plasma sFasL could be detected in uremic and HD patients, but not in healthy controls. There was no significant difference in levels of plasma sFasL between non-dialyzed and HD patients, pre- and post-dialysis session, and patients treated with polysulfone and cellulose dialyzer. When monocytes were cultured in vitro with rHu-FasL for 2 hours, higher levels of apoptosis and lower survival rate were found in monocytes from HD patients as compared with those from healthy controls. CONCLUSION: The up-regulated expression of functional Fas on monocytes and the presence of sFasL in plasma may contribute to the accelerated apoptosis of monocytes seen in uremic patients.

Adult↗

PubMed2001

Ground simulation of the G-excess illusion.

Objective. To observe the subjects' perception of orientation following certain head movements or change of simulator cab attitude in hypergravity (HG), and assess the feasibility of simulating G-excess illusion on the ground by a centrifuge-like Spatial Disorientation (SD) simulator. Method. 1.6 G force field was generated by planetary rotation of the simulator. Perception of orientation of the cab were collected from twelve male pilots' report following their heads pitch movements in pitch plane or cab attitude changes in roll plane under 1.6 G. Result. While making a pitch-up head movement, the pilots experienced a 63.8 degrees +/- 48.3 degrees pitch-up attitude change of the cab in pitch plane, and when the cab was tilted left 20 degrees, pilots experienced a tilt-left perception of 48.6 degrees +/- 39.4 degrees in roll plane. Conclusion. Although there's strong Coriolis effects onboard the SD simulator under 1.6 G, most pilots experienced the G-excess illusion. It demonstrated that it was feasible to use the centrifuge-like device to generate this kind of illusion on the ground.

Adult↗

PubMed2001

[The biological effects of transforming growth factor-beta on human periodontal ligament fibroblasts].

OBJECTIVE: To evaluate the biological effects of transforming growth factor-beta (TGF-beta) on human periodontal ligament fibroblasts (HPDLFs). METHODS: HPDLFs were primary cultured and examined for the effects of TGF-beta on its proliferation, alkaline phosphatase (ALP) activity, osteocalcin (OC) synthesis and formation of the mineralized nodules. RESULTS: TGF-beta(0.0050-0.1000 mg/L) significantly stimulated the proliferation of HPDLFs. The ALP activity of HPDLFs was elevated evidently by 0.0050 mg/L TGF-beta. TGF-beta (0.0005-0.1000 mg/L) had no effects on OC synthesis and formation of the mineralized nodules of HPDLFs. CONCLUSIONS: The effects of TGF-beta on HPDLFs are dose-dependent. TGF-beta can stimulate HPDLFs to express some of osteoblastic phenotype, and it lacks the abilility to promote maturation of the osteogenic phenotype.

Alkaline Phosphatase↗

PubMed2001

Temporal bone fracture and its complications.

OBJECTIVE: To explore the characteristics and treatment of temporal bone fractures and injuries in the medial-inner ear. METHODS: The clinical data of 48 cases of temporal bone fractures admitted to our hospital from January 1989 to November 1999 were retrospectively analyzed. RESULTS: Forty-eight patients with temporal bone fractures accounted for 17.00% of the homochronous craniofacial fractures. Of the 48 cases, temporal bone fractures induced by traffic accidents accounted for 66.67%, capillary fractures for 93.75%, medial inner ear injuries or craniocerebral injuries for 77.08% and hearing loss or tinnitus for 48.00%. The cerebrospinal fluid (CSF) otorrhea and facioplegia accounted for 36.70% and 3.00%, respectively, in the longitudinal fractures, while they were 25.00% and 37.50%, respectively, in the transversal fractures. Primary emergent operations were performed on 46 cases and neurosurgery accounted for 46.00%. Secondary procedures accounted for 16.70%. As a result, 43 cases survived (89.58%) and 5 died (10.41%). CONCLUSIONS: Traffic injury is the first high-dangerous factor for temporal bone fractures, which are often complicated with medial-inner ear or craniocerebral injury. The CSF otorrhea is common in the longitudinal fractures and facioplegia is common in the transversal fractures. The key step is to rescue the life, keep the airway unobstructed and maintain the circulation in the primary emergency treatment.

Adolescent↗

PubMed2001

[A novel Fe/AC desulphurizer at low temperature].

Activated coke was used to support Fe2O3(Fe/AC) for flue gas SO2 removal. Reaction conditions on DeSOx activity were investigated. The results show that Fe/AC had higher activity than AC or Fe2O3 at temperature of 120 degrees C-250 degrees C. H2SO4 and Fe2(SO4)3 were formed after Fe/AC sorbed SO2, H2O and O2 increased the amount of SO2 adsorption. Fe/AC derived from AC of higher BET surface area had higher DeSOx activity. Fe/AC was suitable to be used at GHSV below 800 L/(kg.h).

Air Movements↗

PubMed2001

[Studies on the manufacture and immunogenicity of purified rabies vaccines on humans Vero cell].

OBJECTIVE: Using Vero cell as basic cultural material to improve the quality of rabies vaccines and to produce rabies vaccines for humans. METHODS: CTN-1V10 strain were used for production. Vero cell of 150th generation were used for cultivation. Rotating cultivatal method with rotating bottle was used. Fluids with virus were collected at different time. Puritied rabies vaccine was produced on Vero cell after clarification, condensation, purification and extermination. A batch of vaccines made by this techniques were used for immunological observation. Sixty-three people were injected with this rabies vaccine according to the procedure of time of exposure. Thirty of them were injected with vaccines made in France (Verorab) while the others were injected with vaccines to be tested. Side effect and neutralizing antibody were recorded. RESULTS: The quality of this newly developed rabies vaccines has met the quality set by WHO. After all dosages of injection, the rates of positive antibody were both 100% in two groups. The neutralizing antibody among testing group was 11.94 IU/ml comparing with control as 11.69 IU/ml. CONCLUSION: Purified rabies vaccines on Vero cell for humans had reasonable manufacture technique and less little effect with good technological imnunogenicity.

Animals↗

PubMed2001

[Corneal topography and pachymetry in normal eyes].

OBJECTIVE: To evaluate the corneal topography and pachymetry on normal eyes. METHODS: The Orbscan corneal topography system was used to investigate corneal topography and pachymetry on 46 normal subjects. RESULTS: In normal eyes, island-shape was the most common type in the elevation topography of anterior corneal surface, followed by incomplete ridge, regular ridge, irregular ridge and unclassified type. For the elevation topography of posterior corneal surface, the most common type was also the island-shape, followed by regular ridge, incomplete ridge and irregular ridge. The thinnest point of cornea in normal eyes was located (0.90 plus minus 0.51) mm away from the visual axis with the thickness of (0.55 plus minus 0.33) mm, which was commonly seen at the inferotemporal quarter of cornea, followed by superotemporal, inferonasal and superonasal quarter. The mean corneal thickness was the least in corneal center and greatest in superior part of cornea. For the color-coded map of corneal thickness, oval shape was the commonest type, followed by round shape, eccentric oval shape and eccentric round shape. CONCLUSIONS: The normal parameters on pan-corneal thickness and corneal shape of both anterior and posterior surface will provide much more useful informations in finding abnormal cornea. Orbscan topography system is a useful instrument for the evaluation of corneal shape and thickness, which is helpful in corneal refractive surgeries.

Adult↗

PubMed2001

[The adherence of leukocytes mediated by L-selectin to endothelia activated by burn sera].

OBJECTIVE: To study the mediating effects of L-selectin on the adherence of rat PMNs to the endothelia activated by burn sera. METHODS: Pulmonary microvascular endothelial cells (PMEC) of rat were cultured by tissue block method. Rat PMNs were harvested by continuous perfusion. The samples were collected for the detection of the adhering rate of PMEC to the PMNs after being cultured with L-selectin monoclonal antibody (mAb), L-selectin ligand and sulfatide, respectively. RESULTS: The adhering rate of PMNs to PMEC was obviously lowered by the adding of L-selectin mAb and sulfatide. CONCLUSION: The adherence of PMNs to activated PMEC could be mediated by L-selectin.

Animals↗

PubMed2001

[Cloning and nucleotide sequencing of full length L segment cDNA of Hantavirus strain A9].

OBJECTIVE: Cloning and nucleotide sequencing of full length cDNA sequence of L segment of Hantavirus strain A9. METHODS: The L segment cDNA of Hantavirus strain A9 was amplified by RT-PCR. PCR products were cloned and sequenced. Full length cDNA clone of the L segment was obtained by subcloning. RESULTS: The L segment of strain A9 was 6 533 nucleotides in length and encoded a putative L polymerase that was 2 151 amino acids in length. Analysis of nucleotide and deduced amino acid sequences of the L segment of strain A9 showed a close relationship with the other Hantaviruses most notably the 76-118, Cl-1 and Cl-2 strains, with which they shared a 83.8% nucleotide identity. More distant similarity could also be seen with other Hantaviruses. Sequence comparison performed among the RNA-dependent RNA polymerases of 27 negative stranded RNA viruses revealed that the same existence of six conserved regions and several strictly conserved residues located at the deduced amino acid sequence of A9 L segment. CONCLUSIONS: The nucleotide sequence of L segment of strain A9 was similar to other Hantavirus L segments. Deduced amino acid sequence of A9 L segment shares 6 conserved regions with other RNA virus RNA polymerase. The conserved residues in these polymerases and their possible functions in light of the available structural information have been discussed.

Amino Acid Sequence↗

PubMed2001

Cyclohexylamino-demethoxy-hypocrellin B and photodynamic therapy decreases human cancer in vitro.

2-Cyclohexylamino-2-demethoxy-hypocrellin B (CHAHB) is a new photosensitizer synthesized by the mild reaction between hypocrellin B (HB) and cyclohexylamine, in which the peri-hydroxylated perylenequinone structure of the parent HB is preserved and the photoresponse is enhanced markedly. Electron paramagnetic resonance (EPR) spin trapping measurements and 9,10-diphenylanthracene (DPA) bleaching studies were employed to investigate the photodynamic action of CHAHB in the presence of oxygen. Singlet oxygen ((1)O2) and superoxide anion radical (O2*-) generated by illuminating CHAHB in aerobic solution have been observed. Compared with HB, CHAHB distinctly enhanced the O2(*-)-generating abilities, although (1)O2-generating abilities were lowered. The photodynamic action of CHAHB in the therapy of cancer was investigated in vitro. The results in vitro revealed a much more significant decrease in cancer cell growth than with HB. Laser or dye alone had no effect, indicating that intratumor CHAHB and laser therapy may prove useful in unresectable cancer.

Cell Line↗

PubMed2001

[A study on transmission of pathogenic bacteria of rampant caries from mothers to children].

OBJECTIVE: In order to prevent rampant caries in children, the transmission from mothers to children of pathogenic bacteria of rampant caries will be investigated in this study. METHODS: By using fingerprint technique, the genetic diversities of Streptococcus mutans(S. mutans) were examined respectively in 10 children with rampant caries, 10 children without rampant caries S. mutans, 10 2-year-old caries-free children, and their mothers. The levels of S. mutans in saliva of mothers were also examined. For fingerprinting, chromosomal DNA of isolates obtained from plaques of these children and from saliva of their mothers were digested with restriction endonuclease HindIII and examined by electrophoresis on 0.7% agarose gel. DNA fingerprints were obtained and analyzed for genotypic similarities. RESULTS: The DNA fingerprint patterns showed that the proportion of children whose genotypes of S. mutans matched their mothers in the children with rampant caries was 70%, which is similar to that in the children without rampant caries and the caries-free children (60% respectively). The number of distinct genotypes of S. mutans harbored in children with rampant caries was, on average, greater than the number of genotypes present in children without rampant caries and caries-free children (1.7, 1.2 and 1.1 respectively, P < 0.05). Mothers of children with rampant caries had similar levels of S. mutans in saliva as those mothers of children without rampant caries and caries-free children. However, mothers of children with rampant caries had significantly higher DMFT scores and higher levels of Streptococcus sobrinus (S. sobrinus) in saliva than the mothers of caries-free children did. CONCLUSION: In all child groups, mothers were probably the main source of infection with S. mutans. Rampant caries in children is associated with DMFT scores and levels of S. sobrinus in saliva of mothers. In the initiation of rampant caries experienced by a child, the transmission of pathogenic bacteria from mothers to children may be the main source.

Adult↗

PubMed2001

[A comparative study of clinical application of two types appliances for maxillary molar distalization].

OBJECTIVE: The aim of this study is to evaluate advantages and disadvantages of two types of appliances for maxillary molar distalization. METHODS: Totally, 28 patients with class II malocclusion resulting from molars shifting mesially were treated using two different molar distalization methods, including using removable and fixed appliances. An intra-oral removable acrylic appliance with headgear for extra-oral traction resulted in tipping the maxillary first molars distally. The modified rapid helix expansion appliance (MRHEA), which consisted of bands, anchorage teeth, Nance palatine bases, helix bars and connecting rods, made the maxillary first molars move parallel distally. RESULTS: The desired efforts were gained in 7 or 9 months by using removable appliances, but only 2 or 2.5 months if using MRHEA. The treatment results of using removable appliances were dependent on patients' cooperation, however, the method of using fixed appliance overcame some shortcomings of other molar distalization techniques, and this appliance would not lead to the distal inclination of the crown of the shifted teeth. CONCLUSION: These two methods could convert the class II molar relationship to class I. The MRHEA can save much chair-side time, and shorten the period of treatment, move molars distally parallel.

Child↗

PubMed2001

[The isolation and identification of pathogenic bacteria from rampant caries in children].

OBJECTIVE: In order to prevent rampant caries in children, the predominant pathogenic bacteria of rampant caries in children were defined. METHODS: The pathogenic bacteria of rampant caries were isolated and identified in 30 children with rampant caries, aged from 2 to 5 years old. Samples were collected from the caries of labial surfaces of maxillary anterior deciduous teeth, including caries lesions and caries-free smooth enamel surfaces. Plaque were obtained from the cervical third areas of the maxillary labial anterior deciduous tooth surfaces in children without rampant caries and caries-free children and served as controls respectively. The isolates were identified by colony morphology, biochemical tests and DNA base contents (mol percent G + C). RESULTS: The prevalence of Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus) in the plaque of caries lesions and the proportions of S. mutans and S. sobrinus in the plaque of 2 sampling sites of children with rampant caries were all significantly higher than those of children without rampant caries and caries-free children (P < 0.05). CONCLUSION: S. mutans and S. sobrinus are predominant pathogenic bacteria in rampant caries in children.

Child↗