Biomedical subjects

Jia Liu

Publications and source records attributed to Jia Liu.

101 records · Page 6Linked to original sources

PubMed2003

[Preparation of liposome containing bacteriorhodopsin with natural preferred orientation of its transient photoresponse].

Bacteriorhodopsin is a membrane protein of halobacteria and functions as a light-driven protein pump. After we isolated bR from cultured halobacteria, bR was mixed with amphiphilic DPPC under different pH. The liposomes were formed after sonication. The remaining biological activity of bR as a proton pump was then verified and pulsed-light-induced proton movement was detected, while liposomes were observed via TEM and light scattering. Although there was no noticeable difference in morphologies of both vesicles formed at pH=2.5 and pH=7.0, the orientations of bR in both liposomes were found to be opposite under these two conditions. This experiment confirmed that the protein bR, when self-assembling into liposomes under acid medium, kept the similar orientation as in the natural plasmid membrane. Such a normal-orientation was, however, different from most of reports in the literature about liposomes prepared under normal neutral conditions.

1,2-Dipalmitoylphosphatidylcholine↗

PubMed2003

Combination of nucleic acid and protein isolation with tissue array construction: using defined histologic regions in single frozen tissue blocks for multiple research purposes.

Precise dissection of defined histological regions for nucleic acid and protein isolation is a precedent step in finding out cancer-related alterations, and high quality tissue microarrays are demanded in the validation of screened genetic alterations by multiple in situ approaches. In this study, a combined technique was developed by which sample isolation and tissue array construction could be performed on the defined morphological region(s) in single tissue block. The RNA and protein samples generated from the selected portions were of good quality and sufficient for multiple experimental purposes. The frozen tissue arrays constructed on a novel recipient are suitable for multiple in situ evaluations including immunohistochemical staining and mRNA hybridisation. In most cases, the data obtained from in situ assays coincided well with the ones revealed by RT-PCR and Western blot hybridisation. The potential experimental bias caused by cell contamination can be amended by tissue array-based retrospective examination. The combination of tissue-selective sample preparations with tissue array construction thus provide a tool by which comprehensive cancer research can be performed on defined histological regions in a series of single frozen tissue blocks.

Animals↗

PubMed2003

[A randomized, double blind, and controlled clinical trial of the non-addictive propacetamol in postoperative analgesia].

OBJECTIVE: To compare the postoperative analgesic efficacy and safety of the non-addictive propacetamol hydrochloride (Pro-Bufferin) injection and dolantin in a prospective, randomized, double blind and controlled clinical trial. METHODS: After the pain intensity was assessed when the patients were undergone thoracic and abdominal selective surgery became fully conscious, 40 consecutive patients with moderate to severe postoperative pain (equivalent to Pain Grade I and II of American Anesthesia Association classification) were randomized into the study against the control groups. The two groups were similar for age, sex, height/weight, disease categories, operation categories, anesthesia methods and duration, vital signs, hepatorenal function, and blood cell count (P = 0.06-0.93). In the study group, 2 g propacetamol in 100 ml normal saline (NS) intravenously with 1.0 ml NS intramuscularly as the placebo control to dolantin were administered. In the control group, 1.6 g mannitose in 100 ml NS intravenously as the placebo control to propacetamol with 50 mg dolantin (1.0 ml) intramuscularly as the positive control to propacetamol were administered. The intensity change of postoperative pain was then evaluated 10 times with visual analog scale and verbal describing scale during 6 h from the beginning of propacetamol infusion. Vital signs and adverse reactions were also documented. After all data were put into the computer, the blinding codes were decoded and the statistic analysis was then made. RESULTS: There was no significant difference (P = 0.93) about the area under the curve of "Pain Relieve Score vs. Time". The "starting to effect" time (15-30 min), analgesic duration (6 h) and the percentage of excellent or good analgesic effect (90%) in the two groups were the same. Adverse reactions didn't reached the statistic different level (P = 0.35). CONCLUSIONS: Propacetamol HCL injection 2 g intravenously could be an alternative to dolantin 50 mg intramuscularly for moderate to severe postoperative pain with its advantage of being non-addictive.

Acetaminophen↗

PubMed2003

[Construction and characterization of frozen tissue microarray with defined histological regions of gastric specimens].

BACKGROUND & OBJECTIVE: In the genome-wide investigation of cancers, high-throughput downstream approach is in urgent need to validate the candidates of cancer associated genes screened by cDNA microarrays. To meet this need, frozen tissue microarrays were constructed using defined histological regions of gastric tissues and their general features were characterized by multiple parameters. METHODS: By the use of self-designed tissue arraying system, 0.7 mm tissue spots were cored from defined histological regions of gastric tissues and orderly filled into the array-recipient OCT(optimal cutting temperature compound) block in the density of 30 spots/0.7 cm(2) or 49 spots/cm(2). The spots of tissue array was characterized histologically, and then by the methods of immunohistochemistry(IHC) and mRNA-in situ hybridization(RISH) for casepase-3. RESULTS: The spot sampling was performed accurately, and the morphology of most tissue spots was kept well after multiple steps of processing. Immunohistochemical staining revealed that casepase-3 was produced in 100.0% of noncancerous gastric mucosa, 66.7% of neoplastic mucosa and 20.0% in cancer tissues. The results of RISH were well coincided with that of ICC in the rates of 90.0%, 60.0%, and 15.4%. CONCLUSION: The frozen tissue array described in this study allows rapid and precise molecular analyses of various gastric lesions in the same experimental conditions. It would be a novel downstream tool in genome-wide study of gastric cancers both in screening and functional elucidation of candidate gastric cancer associated genes.

Freezing↗

PubMed2002

Stages of processing in face perception: an MEG study.

Here we used magnetoencephalography (MEG) to investigate stages of processing in face perception in humans. We found a face-selective MEG response occurring only 100 ms after stimulus onset (the 'M100'), 70 ms earlier than previously reported. Further, the amplitude of this M100 response was correlated with successful categorization of stimuli as faces, but not with successful recognition of individual faces, whereas the previously-described face-selective 'M170' response was correlated with both processes. These data suggest that face processing proceeds through two stages: an initial stage of face categorization, and a later stage at which the identity of the individual face is extracted.

Adolescent↗

PubMed2002

Cytopathological evaluations combined RNA and protein analyses on defined cell regions using single frozen tissue block.

The co-existence of multiple cell components in tissue samples is the main obstacle for precise molecular evaluation on defined cell types. Based on morphological examination, we developed an efficient approach for paralleled RNA and protein isolations from an identical histological region in frozen tissue section. The RNA and protein samples prepared were sufficient for RT-PCR and Western blot analyses, and the results obtained were well coincident each other as well as with the corresponding parameters revealed from immunohistochemical examinations. By this way, the sampling problem caused by cell-cross contamination can be largely avoided, committing the experimental data more specific to a defined cell type. These novel methods thus allow us to use single tissue block for a comprehensive study by integration of conventional cytological evaluations with nucleic acid and protein analyses.

Blotting, Western↗

PubMed2002

Effect of tubule orientation and dentin location on the microtensile strength of bovine root dentin.

To investigate the mechanical properties of root dentin and to further clarify the cause of vertical root fracture (VRF), this study evaluated the effect of tubule orientation (parallel, perpendicular and oblique to the cross-section of dumbbell specimens in microtensile tests) and dentin location (cervical, middle, and apical location of the root) on the microtensile strength of bovine root dentin. Each specimen was stressed in tension at a crosshead speed of 1.0 mm/min. The results of the microtensile strength measurements were statistically analyzed with one-way ANOVA and the Fisher PLSD. The oblique group (95.18+/-23.80 MPa) was significantly (p<0.01) higher than the parallel group (38.93+/-5.28 MPa) or the perpendicular group (32.64+/-4.69 MPa). There were no significant differences among the different dentin locations within the parallel group (p>0.05). It was clarified that the VRF occurs frequently in practical situations due to the tubule orientation of root dentin.

Analysis of Variance↗

PubMedDate not supplied

CYP1A1 and CYP1B1 expressions in medulloblastoma cells are AhR-independent and have no direct link with resveratrol-induced differentiation and apoptosis.

Resveratrol induces apoptosis and regulates CYP1A1 and CYP1B1 expression in human medulloblastoma cells. To elucidate the potential correlation of their expressions with the anti-medulloblastoma effects of resveratrol, human medulloblastoma cells, UW228-3, were treated with CYP1A1 selective inhibitor (alpha-naphthoflavone, alpha-NF), selective CYP1A1/1A2 inducer (beta-naphthoflavone, beta-NF) and their combination with resveratrol, respectively. The influences of those treatments on the expressions of CYP1A1, 1A2 and 1B1 as well as the cell growth, differentiation and death were analyzed. It was found that neither alpha-NF nor beta-NF had any effect on cell growth. alpha-NF inhibited resveratrol-induced CYP1A1 expression without interfering cell differentiation and apoptosis. beta-NF could up-regulate resveratrol-induced CYP1A1 expression but not enhance the anti-cancer effects of resveratrol. CYP1A2 was undetectable in the cells irrespective to the treatments. Aryl hydrocarbon receptor (AhR) was absent in UW228-3 cells under normal culture and treated with resveratrol but induced by both alpha- and beta-NF. Immunohistochemical examination performed on 11 pairs of human medulloblastoma and noncancerous cerebellar tissues revealed that AhR was undetectable in either of them, whereas CYP1A1 was expressed in cerebellum but down-regulated or diminished in their malignant counterparts. Our data suggest for the first time that CYP1A1 and 1B1 expressions in human medulloblastoma cells are AhR-independent and have no direct links with resveratrol-induced differentiation and apoptosis. Appearance of CYP1A1 expression may reflect a more maturated status and a better prognosis of medulloblastomas.

Apoptosis↗

PubMedDate not supplied

Lipid abnormalities associated with end-stage renal disease.

Patients undergoing chronic renal replacement therapy have a high incidence of dyslipidemia. In general, there are increased concentrations of triglyceride-rich apolipoprotein B-containing particles. These elevations lead to increased levels of non-high-density lipoprotein (HDL) levels. This pattern is further modified by the method of dialysis (peritoneal versus hemodialysis) and comorbidities such as diabetes. End-stage renal disease patients also demonstrate increased levels of lipoprotein(a) (Lp(a)) and oxidized low-density lipoprotein (LDL)both of which are highly atherogenic. This review focuses on the pathogenesis of these lipid abnormalities and their role in the atherosclerotic process.

Dyslipidemias↗

PubMedDate not supplied

Management of lipid abnormalities associated with end-stage renal disease.

The management of lipid abnormalities in patients with end-stage renal disease (ESRD) remains controversial. Large, well-designed studies investigating the effects of dyslipidemia on cardiovascular (CV) morbidity and mortality and the role of cholesterol lowering drugs in reducing mortality in ESRD patients are lacking. While it seems reasonable to suspect that dyslipidemia and its treatment in ESRD patients will affect CV morbidity and mortality similar to that in the general population, recent studies have suggested that this may not be the case. Furthermore, the pharmacokinetics of lipid lowering drugs are altered in patients with ESRD and must be considered when treating this group of patients. This article reviews the major classes of drugs used to treat dyslipidemia, emphasizing their role in patients with ESRD.

Antioxidants↗

PubMedDate not supplied

Differential expression patterns of hyaluronan receptors CD44 and RHAMM in transitional cell carcinomas of urinary bladder.

Recurrence due to invasive growth is the major risk factor of transitional cell carcinoma (TCC) of urinary bladder. The interactions of hyaluronic acid (HA) and its receptors, CD44 and RHAMM, on cancer cells can promote invasion and metastasis but parallel study on these two genes in TCCs has not been available. The current work is aimed to address this issue by frozen tissue array-based immunocytochemical staining and Western blot hybridization. The results revealed that 19 out of 28 non-cancerous mucosa (68%) expressed CD44, in which 9 (33%) harbored variant exon 6 (v6). CD44 and v6 were both 5/11 (46%) in papillary, non-invasive carcinomas (pTa) and 6/14 (43%) in the tumors remained in sub-epithelial layer (pT1), while 5/29 (17%) and 3/29 (10%) in pT2-4 invasive tumors. RHAMM expression was uncommon in non-cancerous mucosa (5/28) but became frequent in pTa (9/11), pT1 (12/14) and pT2-4 (24/29) tumors. RHAMM proteins were labeled intracellularly and showed more than one isoforms. Our data further confirm the promising prognostic value of CD44 for TCC patients and demonstrate, for the first time, the correlation between RHAMM expression and malignant transformation of urothelial cells.

Adenocarcinoma↗