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Biomedical subjects

J Liu

Publications and source records attributed to J Liu.

At least 847 records · Page 47Linked to original sources

[The RYR1 genotype of Chinese inbred pigs].

OBJECTIVE: Porcine stress syndrome (PSS) is one kind of molecular genetics defect diseases of pig which will cause malignant hyperthermia syndrome (MHS) and is the first index should be excluded in screening of a pig species for xenotransplantation. It was reported that mutation of pig rynodine receptor(RYR1) gene is the main reason for PSS. In this study, RYR1 genotypes of the Chinese Banna mini pig inbred line and inbreeding closed colony Wuzhishan pig were investigated with polymerase chain reaction-restriction endonuclease fragment length polymorphism (PCR-RFLP) technique. METHODS: Antevenocaval whole blood samples were collected from 50 Banna mini-pig inbred-line(BMI), 15 inbreeding Wuzhishan pig (WZSP) and 25 Neijiang pigs (NJP) as negative control, the primer were designed and synthesized, PCR reaction was conducted following the sequence of 94 degrees C (1 min), 58 degrees C (1 min) and 72 degrees C (1 min) for 30 cycles. The PCR products were digested with restriction endonuclease HhaI and then electrophoresis check. RESULTS: A 659 bp DNA fragment was amplified with these two primers, the HALNN sample fragment was cut into fragments as 493 bp and 166 bp individually after the digestion, indicates no point mutation at site 1,843 in RYR1 gene in all tested BMI pig and WZSP. Namely, the RYR1 genotype of 50 cases of BMI and 15 cases of WZSP were HALNN, therefore their phenotype is PSS negative. CONCLUSION: It indicates that the genotype of Banna mini pig inbred line and inbreeding Wuzhishan pig are HALNN therefore PSS absolutely negative, the group penetrance is 0. This is consistent with experimental observation. It suggests that Banna mini pig inbred line and inbreeding Wuzhishan pig may be the alternative donor for xenotransplantation.

Animals↗

[Effect of estrogen on the expression of c-myc protein of bone in mice].

In order to study the mechanism by which estrogen effects on bone, the effect of estrone on expression of c-myc protein in the epiphyseal plate of fetal mouse long bone was detected by immunohistochemistry procedure in vitro. The result showed that the concentrations of estrone areas of positively staining cells increased significantly in proliferative zone at 10(-9) mol/L, in proliferative zone and resting zone at 10(-8) mol/L, and in resting zone, proliferative zone and hypertrophic zone at 10(-7) mol/L respectively. It was considered that estrogen might enforce endochondral bone formation by enhancing expression of c-myc in long bone.

Animals↗

[Evaluation of cariogenic potential of Streptococcus mutans isolated from caries-free and -active persons: abilities to synthesize water-soluble and -insoluble glucans].

OBJECTIVE: In this study, authors investigated abilities of Streptococcus mutans (serotype c) strains to synthesize water-soluble and water-insoluble glucans. METHODS: Streptococcus mutans strains were isolated from people with different carious experiences, which were divided into two groups: caries-free (DMFS = 0) group including 19 persons and caries-active group(DMFS > or = 6) including 40 persons. Totally 105 genotypes of Streptococcus mutans strains were obtained, including 22 strains from the caries-free group and 83 strains from the caries-active group. The differences of abilities to synthesize water-soluble and water-insoluble glucans between these two groups were compared in order to find the correlationship between the synthesis of glucans and caries experience. Then, Streptococcus mutans were cultured in TPY liquid medium containing 1% sucrose in an anaerobic incubator at 37 degrees C for 24 hours. Glucans synthesized by Streptococcus mutans was qualified by using infrared spectrophotometry. The amounts of water-soluble and water-insoluble glucans were measured by using the anthron method. RESULTS: According to the same absorption tops position analysed by infrared spectrophotometry, glucans samples were certified. The amounts of glucans synthesized by Streptococcus mutans strains were different between strains of different genotypes even isolated from the same person. Mostly, the amount of water-insoluble glucans was higher than that of water-soluble glucans between different genotype Streptococcus mutans strains. The oral environments of patients in the caries-active group harbored more Streptococcus mutans strains with higher water-soluble glucans producing ability than those of the caries-free group did (P < 0.05), and patients of the caries-active group also harbored more Streptococcus mutans strains with higher water-insoluble glucans producing ability than those of the caries-free group did(P < 0.01). CONCLUSION: 1. Glucosyltranferases of different genotype strains are different in glucans production, and different genotype strains relate to different cariogenic abilities. 2. Glucans was one of cariogenic factors, and water-insoluble glucans was more important than water-soluble glucans in cariogenic ability of Streptococcus mutans. 3. The differences in glucans production of isolated strains might relate to differences in carious experiences.

Dental Caries↗

[Studies on thymidine kinase gene (TK) and GCV system for treatment of human retinoblastoma (RB)].

The antitumor effect of herpes simplex virus thymidine kinase (HSV-TK)/GCV system on human retinoblastoma (RB) was studied here. A retroviral vector with tk gene (pLXSN-TK) was transduced into packaging cell line PA317. Recombinant retroviral was obtained and employed to infect human RB cells. The in vitro efficacy of TK/GCV was evaluated by survival rate of RB cells with and without TK transduced 5 days after treated with GCV. A nude mouse model with heteroplantation of human RB was established to examine the in vivo efficacy. Mice with RB were given an in situ injection of retrovirus followed by treatment with GCV for 14 days (50 mg/kg). The RB/TK cells in tissue culture dish showed far more sensitive to GCV than RB cells. The tumors in RB mice with TK gene transduced were much smaller than those in control. The results indicate that HSV-TK/GCV system can suppress growth of RB both in vitro and in vivo. It could be a valuable method for treatment of RB patients.

Animals↗

[A study on the determination method of biological function of BRF].

This study was aimed to establish a method for determining the biological function of biological wave regulating factor (BRF). Proteus mirabilis was used to set up the experimental model. The biological function of the component obtained from wave growth media beneath the bacterial colony rings resulting from bacterial proliferation was determined in biological wave test by analytically microbiological method. The results indicated that BRF could enhance biological wave and shorten its period. The method is of some value in studying the regulative mechanism of biological wave.

Bacterial Proteins↗

[Alteration of free radical generation in pulmonary tissue after quick decompression].

The purpose of this experiment was to evaluate decompression-induced pulmonary injury by means of measurement of ascorbate free radical (Vc-.) alteration in pulmonary tissue of the rats which experienced rapid decompression. 29 male S-D rats were divided into 4 groups: A was executed at 45 min post-decompression; B was control for A; C was executed at 90 min; D was ontrol for C. Group A and group C were to compress up to 0.5 MPa(air) and stay for 60 min, then were decompressed smoothly to normbaric in 1 min. The 0.05 M N-tert-butyl-alpha-phenylnitrone (PBN) was given at 20 min after completion of decompression (groups A and B) or at 65 min (groups C and D). At 25 min after PBN injection the animals were killed by cutting arteria coeliaca, and 0.75 g pulmonary tissues were taken. These tissues were homogenized for electron paramagnetic resonance (EPR) assay. The results demonstrated that the ascorbate free radical (Vc-.) signals were obtained at all samples. The intensity of signals measured in group C rose markedly (P < 0.05) and that in group A was close to control's. So it can be concluded that rapid decompression would increase the generation of free radical in lung.

Animals↗

[The effect of artesunate in preventing the populations from Schistosoma japonicum infection during flood-control].

OBJECTIVE: To evaluate the prophylactic effect of artesunate in high-risk populations who had contacted the infested water. METHODS: From the 7th day post-exposure to infested water, a total of 17,031 people who had contacted the infested water for more than 20 days had been treated with artesunate at a dose of 300 mg once a week for three successive weeks. On day 17 after the last medication, they were examined for schistosomiasis and followed-up 60 days later. RESULTS: No acute schistosomiasis case was found. ELISA-positive was found in 204(1.20%) and COPT > 3% was found in 195 cases (1.14%). The side-effects were slight. CONCLUSION: Artesunate is highly effective and safe for the prevention of schistosomiasis.

Adolescent↗

[Analysis of Amomun villosum species and some adulterants of zingiberaceae by RAPD].

Different Amomum villosum Lour. species and some their adulterants of Zingiberaceae were researched using RAPD. The PCR indicates favourable differentiation of the reaction. The Amomum villosum Lour. species have the similar DNA fingerprints while it is obviously differ from adulterants. There are 12.17 percent of primers which appear polymorphism. We can identify different species according to these dissimilarity. We also construct the tree of the molecular evolution through NJ software, the hereditary distance of the graph shows different relationships between Amomum villosum Lour. species and their adulterants. The result created by software is analogous the traditional methods.

Amomum↗

[The histological changes after preserved human amniotic membrane transplantation for conjunctival reconstruction of rabbits eyes].

PURPOSE: To investigate the histological changes after preserved human amnotic membrane transplantation of rabbit eyes. METHODS: The conjunctiva of 12 New Zealand albino rabbits' right eyes were excised partly. Then the preserved human amniotic membrane were transplanted on the sclera. Eyes were enucleated at 1 week, 3 weeks, 5 weeks and 12 weeks (n = 3 for each) after surgery, and they were examined histologically with staining of HE, PAS, and transmission electronic microscopy. RESULTS: At 1 week after transplantation, the human amniotic membrane firmly attached on the sclera, with the dead epithelial cells remaining on its surface. At 3 weeks, conjunctival epithelization was completed on the human amniotic membrane. Abundant PAS-positive goblet cells were recognized. The amnion began resolve. At 12 weeks, the amnion dissolved. On transmission electronic microscopy, the cell polarity is prominent. The epithelial cells contained a large number of mitochondria and endoplasmic reticulum. Microvilli were pronounced on the apical cell membrane. There are many intracellular desmosomes and hemidesmosomes. CONCLUSION: Preserved human amniotic membrane is a valuable conjunctival replacement material. After transplantation, the histology of new tissue is as same as normal conjunctive.

Amnion↗

[The role of mtDNA deletion in the sensitivity to aminoglycoside antibiotic induced deafness].

OBJECTIVE: To establish an animal model of mitochondrial DNA (mtDNA) deletion and investigate the possible role of mtDNA deletion in aminoglycoside antibiotic induced deafness. METHODS: Thirty wistar rats (4 months) were randomly divided into group A and B. Doxorubicin (DOX) was subcutaneously injected at doses of 2 mg/kg twice per week for 3 months in group A and then kanamycin (KM) was intraperitoneally injected 500 mg/kg per day for 10 consecutive days. The treatments of group B were identical to group A, except normal saline was substituted for DOX. The thresholds of auditory brainstem response (ABR) were measured before and after the drug administrations. The inner ear membranous labyrinthine tissue was harvested and mtDNA was amplified to identify 4,834 bp deletion by PCR technique. RESULTS: The elevation of the mean ABR thresholds in group A(67.08 +/- 8.59) dB peSPL was significantly higher than that in group B (12.71 +/- 4.42) dB peSPL after KM administration (P < 0.001). In group A, 9 of the 15 rats demonstrated 4,834 bp mtDNA deletion. However, mtDNA 4,834 bp deletion was negative in group B animals. CONCLUSION: DOX can induce mtDNA deletion in the inner ear tissue of the rat. mtDNA deletion in the inner ear may play an important role in the hypersensitivity to aminoglycoside antibiotic ototoxicity.

Animals↗

[Giant cell reparative granuloma of the skull].

OBJECTIVE: To investigate the clinical course, histologic feature, diagnosis, differential diagnosis and treatment of giant cell reparative granuloma (GCRG). METHODS: Three cases of GCRG, which arose in the skull, were collected from 1987 to 1999 and analyzed clinicopathologically. RESULTS: Two patients had the lesion in the temporal bone and one in the orbit. One patient with GCRG had a recurrence after incomplete surgical resection. Histologically, all of three cases were characterized by fibroblastic proliferation with osteoclast-like giant cell rich areas, hemorrage, and newly formed bone or osteoid trabeculae. GCRG appeared as a typical bony lytic lesion on computed tomography (CT) and as low signal intensity on both T1 and T2 weighted images on magnetic resonance imaging (MRI). CONCLUSION: GCRG is an uncommon nonneoplastic lesion that typically arises in mandible and maxilla and its involvement in skull is rare. Although behaves benignly, GCRG may be locally aggresive. It is usually misdiagnosed for a giant cell tumor (GCT). Diagnosis of GCRG is based on typical histologic features as well as clinical information. Complete surgical resection is believed to be the most suitable treatment for GCRG and long-term follow-up by CT scanning is essential.

Adult↗

[Effect of alginate purity on microencapsulated hepatocyte overgrowth in peritoneal transplantation].

OBJECTION: To study the effect of alginate purity on microcapsule overgrowth in peritoneal transplantation. METHODS: Alginate was purified by filtration and chloroform/butanol extraction. Using purified and crude alginate to make two kinds of microencapsulated hepatocytes (MHs), we transplanted 5 ml of each kind of MHs into the peritoneal cavities of rats. After 2 weeks, 1, 2, and 6 months, MHs were washed out to study overgrowth of MH, histology, enzyme and albumin of hepatocytes. Human lymphocytes transformation was measured by 3H-TdR incorporation with two kinds of alginate solutions. RESULTS: The amount of retrieved MHs was larger in the purified than in the crude ( P < 0.01). In the purified groups, most hepatocytes had normal features of morphology, enzymatic histochemistry, and albumin immunohistochemistry staining after one month of transplantation, but were damaged in the crude groups only 2 weeks later. Microcapsules were smooth, regular and had no overgrowth during 6 months in the purified but overgrowth one month later after transplantation in the crude. The liquid scintillation counting (cpm) was lower in the purified than in the crude. CONCLUSION: The purified alginate could reduce the overgrowth of MH and improve the function of hepatocytes significantly.

Alginates↗

Effects of XW630 on bone formation in ovariectomized rats and in human osteoblast-like cells.

OBJECTIVE: To study the effects of XW630 on bone formation in overiectomized (OVX) rats and in human osteoblast-like cell line TE85. METHOD: Bone histomorphometric analysis was performed with undecalcified bone sections and tetracycline intraperitoneally labeling. RESULTS: Compared with that of OVX rats, the static data of trabecular bone volume (TBV)/total tissue volume (TTV), TBV/sponge bone volume (SBV) and mean trabecular plate density (MTPD) were enhanced while mean trabecular plate spacing (MTPS) decreased after treated with XW630 for 13w. The dynamic data of single-labeled surface [Sfract(s)], double-labeled surface [Sfract(d)], Sfract(d+1/2s), trabecular osteoid surface (TOS) and bone formation rate in tissue level (Svf) were increased and osteoid maturation period (OMP) shortened in XW630 group. In osteoblast-like cells, both 3H-thymidine incorporation and cell count increased after treated with XW630 for 48. Treated with XW630 for 12 approximately 18h, inducible nitric oxide synthase (iNOS) activity and cGMP content increased in time-dependent manners. CONCLUSIONS: XW630 enhanced bone activation frequency and increased trabecular connectivity, stability, and strength. The cellular mechanism related to effects of XW630 on bone formation in ovariectomized rats.

Animals↗

[A clinic analysis of 62 male patients with lupus nephritis].

To study the difference between male and female patients with lupus nephritis(LN), we made a retrospective analysis. The clinical characteristics of 62 male patients with LN were compared with 62 female patients with LN. The result indicated the distribution of LN onset ages was different between male and female patients with LN. The incidence of LN was higher in the male than in female patients with SLE. Male patients were often misdiagnosed or diagnosed long after the onset of the disease. Arthritis and positive rate of ANA were less commonly occurred in female patients with LN. Other clinical and pathologic features of LN were similar in male and female patients. The response to treatment and prognosis of male patients with LN was relatively poor. So male patients with LN should be paid more attention to.

Adolescent↗

[Mechanisms of opioid receptor-induced elevation in intracellular calcium by confocal laser scanning microscopy].

OBJECTIVE: To determine the acute and chronic effects of opioid receptor agonists on the intracellular free calcium concentration ([Ca2+]i) in NG-LNCXiNOS cells, stably expressing iNOS gene, and regulation of G-protein on opioid-induced response in [Ca2+]i. METHODS: A single cell [Ca2+]i is measured by confocal laser scanning microscopy using Ca(2+)-sensitive dye Fluo-3 as an new calcium fluorescent probe. RESULTS: DPDPE(D-Pen2, D-Pen5-enkephalin), a delta-opioid receptor agonist, and morphine acutely induced the increase in [Ca2+]i of NG-LNCXiNOS cells. The elevation in [Ca2+]i by DPDPE could be abolished with naloxone. Pretreatment of the cells with pertussis toxin (PTX) at 100 ng/ml for 24 hours almost completely blocked morphine-evoked response. In contrast to acute effect of opioid agonists on [Ca2+]i, the cells exposed to 1 mumol/L DPDPE or 10 mumol/L morphine for 48 hours also appeared to raise [Ca2+]i. However, the elevation in [Ca2+]i was not greater than that caused by acute effect of DPDPE or morphine. After cell "withdrawal" was precipitated by the addition of 10 mumol/L naloxone, the increase in [Ca2+]i could further be intensified. CONCLUSIONS: The opioid agonist-induced increase in [Ca2+]i is mediated by opioid receptor and regulated though PTX-sensitive G-protein. The attenuation of this response in chronically treated cells with opioid agonist is associated with receptor desensitization.

Calcium↗

[Changes of AC/cAMP system and phosphorylation regulation of adenylate cyclase activity in brain regions from morphine-dependent mice].

OBJECTIVE: To further understand the changes of AC/cAMP system in the brain regions from morphine-dependent mice. METHODS: By inducing morphine dependence in mice, we observed changes in AC/cAMP signal system, the phosphorylation regulation of adenylate cyclase (AC) activity in brain regions and effect of protein kinase A (PKA) inhibitor on the development of morphine dependence. RESULTS: (1) In morphine-dependent mice, AC activity, cAMP contents, and cytosolic PKA activity in striatum, hippocampus, and cerebral cortex were significantly higher than those of control. But there were no similar changes in cerebellum, and PKA inhibitor injected intracerebroventricular 15 min prior to morphine injection could inhibit the changes of AC activity; (2) These changes described above were not observed in mice treated with naloxone 30 min prior to daily morphine injection; (3) In striatum and cerebral cortex of morphine-dependent mice, level of AC phosphorylation in vitro was apparently higher as compared to control group. It indicated that the level of AC phosphorylation in vivo was decreased in morphine-dependent mice; (4) PKA inhibitor was given to mice intracerebroventricular (i.c.v.) 15 min. prior to daily morphine injection could prevent the development of morphine dependence in mice. CONCLUSIONS: The up-regulation of AC/cAMP-PKA signal system in some brain regions occurred in the state of morphine dependence and the effect was mediated via specific activation of opiate receptors. Furthermore, that PKA affecting AC phosphorylated state and leading to the increase of AC activity suggest that the increase of PKA activities during chronic morphine treatment could lead to the positive feedback regulation in AC/cAMP system and further potentiate the AC/cAMP system, and these may be one of important mechanisms by which chronic opiate induce dependence in target neurons.

Adenylyl Cyclases↗