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Biomedical subjects

L Liu

Publications and source records attributed to L Liu.

At least 451 records · Page 25Linked to original sources
PubMed2000

[Toxic effects of aluminum on human embryonic cerebral neurocytes in vitro studies].

OBJECTIVE: To study the toxic effect of aluminum on human embryonic cerebral neurocytes in vitro studies. METHODS: Human embryonic cerebral neurocytes were divided into three groups (control, low Al and high Al groups). The growth, development and morphology of neurocytes were observed by light and electron microscopy. The protein, DNA, lipid peroxide (LPO) contents and the activity of neuron-specific enolase (NSE) and cholinesterase (CHE) of neurocytes were detected. RESULTS: The number of viable cells in high Al group was significantly lower than that in the control group (P < 0.05). The number of swelling, degenerated and necrotic cells was significantly increased in high Al group. The DNA content and the activity of NSE and CHE of neurocytes were significantly decreased with the increase of Al concentrations (P < 0.05). The LPO content of neurocytes in the high Al group was significantly higher than that in the control group (P < 0.05). There was a positive correlation between the Al dose and LPO content of neurocytes (P < 0.05). The electron microscopy study showed that the membrane structure of cell was damaged in the high Al group and the arrangement of microtubules in the processes was disordered. CONCLUSIONS: The growth, development and function of human embryonic cerebral neurocytes was inhibited in the high Al group. The neurotoxicity of Al may be caused by lipid peroxidation and the damage of cell membrane.

Aluminum↗
PubMed2000

[Study on the needle biopsies of 100 prostatic adenocarcinoma].

OBJECTIVE: To study the morphological diagnostic criteria of prostatic adenocarcinoma in needle biopsy. METHODS: 250 cases of prostatic needle biopsy including 100 cases of adenocarcinoma were observed retrospectively. The diagnostic significance of 20 parameters of morphological criteria including the architectural changes, cytologic features, invasion and some additional histologic features (intraepithelial neoplasm, intraluminal crystelloid body, intraluminal basophilic mucin secretion, collagen nodule and coagulative necrosis) were analyzed. RESULTS: All 20 parameters of morphological criteria had practical significance in pathologic diagnosis, the most significant ones being architectural changes, prominent nucleoli, perineural and stromal invasion. CONCLUSION: The diagnosis of prostatic adenocarcinoma is based on a constellation of cytologic and architectural features.

Adenocarcinoma↗
PubMed2000

[Histological diagnosis of regional lymph node micrometastasis with or without stromal reaction in gastric carcinoma].

OBJECTIVE: To define lymph node micrometastasis and to investigate the difference between micrometastasis and microinvolvement. METHODS: A total of 1,087 regional lymph nodes were collected from surgical specimens of 17 patients with gastric carcinoma. 71 nodes were found to contain microlesions, 60 sections per node) and immunohistochemistical staining for CK18, EMA and SAM. Another 20 nodes containing macrometastasis were also studied. RESULTS: After serial sections, the microlesions disappeared in 34% (24 nodes), increased in 49% (35 nodes), microlesions transformed into macrometastasis in 17% (12 nodes). Microlesions presented as a cluster of tumor cells (<or= 0.5 mm) or scattered single cells (<or= 50 cells). Stromal reactions surrounding the clustered tumor cells were found in 50.0% of nodes while stromal reactions surrounding scattered cells were found in 10.5% of nodes. There was no consistent stromal reaction either in nodes with micrometastasis or nodes with macrometastasis, not even within a same node. Stromal reaction was more often found in the higher differentiated group. CONCLUSION: (1) A few sections per node cannot define the nodal micrometastasis and nodal macrometastasis may be misjudged as micrometastasis without serial sections, leading to undestaging of pN. (2) The use of stromal reaction to differentiate nodal micrometastasis from nodal microinvolvement, as suggested by Siewert, is not substantiated.

Actins↗
PubMed2000

[A comparative study on the expressions of IL-4, IFN-gamma and TNF-alpha in BMMNC of acute and chronic aplastic anemia patients].

OBJECTIVE: To detect the induced levels of IL-4, IFN-gamma and TNF-alpha in the supernatant of bone marrow mononuclear cells (BMMNC) and compare the difference of immune status between acute (SAA) and chronic (CAA) aplastic anemia patients. METHODS: Concentrations of IL-4, IFN-gamma and TNF-alpha in PHA-P-induced BMMNC supernatants were determined by ELISA assay in 11 SAA and 13 CAA patients as well as 16 controls. Concentration differences between the two groups were compared. RESULTS: (1) The IFN-gamma and TNF-alpha levels in AA patients studied were much higher than that in controls, and IL-4 levels were normal in SAA group but elevated in CAA group. (2) TNF-alpha levels were comparable between the two AA groups, but both IL-4 and IFN-gamma levels were significantly different between them. CONCLUSION: Enhanced cellular immunity seems to play an important role in the pathogenesis of SAA, and enhancement of both cellular and humoral immunity might contribute to the pathogenesis of CAA.

Acute Disease↗
PubMed2000

[Repair on the traumatic defect of metacarpophalangeal joint by the cartilage transplantation of metatarsophalangeal joint].

OBJECTIVE: To present a simple and reliable method for the reconstruction of metacarpophalangeal joint by the cartilage transplantation of metatarsophalangeal joint. METHODS: From 1990, nine cases (11 sides) with traumatic metacarpophalangeal joint defect were treated by the autogenous cartilage transplantation of metatarsophalangeal joint followed by modified treatment. Appropriate biological mechanics was provided by internal fixation and collateral ligament repair. RESULTS: Followed up 6 months to 7 years, the range of joint motion was increased 35.1 degrees. The fusion of donor phalanges was fine, and the range of joint motion was decreased, even ankylosis after plastic operation, but no pain and no effect on walk. CONCLUSION: The key to successful operation is better matching of cartilage, reliable internal fixation, ligament reconstruction, thin cartilage and little bone of the donor, appropriate biological mechanical surroundings.

Adult↗
PubMed2000

[A study on quality standard for herba cistanches].

OBJECTIVE: To establish the quality standard for Herba Cistanches. METHOD: A qualitative identification method by TLC was established for five kinds of active components(acteoside, echinacoside, cistanoside A, betaine and mannitol) and RP-HPLC was used to quantify the acteoside contents. RESULTS: Qualitative and quantitative analyses were carried out for fourteen kinds of Herba Cistanches and eleven kinds of Yinpian. This method is accurate, reliable and of good separability and reproducibility. CONCLUSION: This method can be applied as standard for the quality control of cistanche deserticola.

Betaine↗
PubMed2000

[Studies on metal porphyrins as two-functional mimic of enzyme].

In this study, four metal porphyrins (tetraphenylporphyrinesulfonatoiron, tetraphenylporphyrinesulfon-atocopper, tetraphenylporphyrinesulfonatomanganese, and tetraphenyl porrphyrinesulfonatocobalt) were used as dual function mimicry of superoxide dismutase (SOD) and catalase (CAT). The first function, scavenging O2.-, has been proved by using riboflavine-methionine photoreduction method in the concentration range of 10(-5)-10(-6) mol/L. The second function, scavenging H2O2, has been demonstrated by means of spectrophotometry, and the percentage of decomposing H2O2 increases with the concentration of the imitating compounds. Metal porphyrins, SOD and CAT were measured by the liver homogenate technique of mice and the results showed that they had obvious action of decreasing the lipid peroxidation. Tetraphenylporphyrinesulfonatomanganese was measured by isolated ischemia reperfusion heart of rats. The results indicated that the Mn-TPPS4 could reduce the damages of active oxygen and had evidently protective effects on isolated ischemia-reperfusion mocardium of rats.

Animals↗
PubMed2000

[Relationship between blood lead and free erythrocyte-protoporphyrin of female workers exposed to low concentration of lead operating environment].

The thesis focused in the research on whether low-lead operation would have effects on female workers. Based on investigation of 82 female workers under an operation environment with lead concentration of 0.0315 mg/m3, the following report indicated that differences did exist in terms of free erythrocyte-protoporphyrin(FEP), lead-blood(Pb-B) and lead-urine(Pb-U) values between the exposure and control groups. Pb-B, FEP and Pb-U were found closely interrelated and comparatively sensitive. Dose-response relationship was discovered in the process, positive percentage of Pb-B and FEP were 20.73% and 21.95% respectively, 13.4% above the maximal standard in both cases. In consequence, it was concluded that exposure to the 0.0315 mg/m3 lead concentration (0.03 mg/m3 being the normal) was still harmful to the female workers. Apart from that, the article suggested that the upper limit of lead in blood for common women (in Changchun city) was properly defined at 1.46 mumol/L. With FEP as the standard, the article made repective comparisons on the female workers' intelligence quotient (IQ) and the symptom occurrence of the neural system. People with IQ value between 60 to 79, 80 to 89, 90 to 109 or 110 to 119, the rates of showing positive report with FEP > or = 0.90 mumol/L were 27.6%, 22.6% and 15.0% respectively. The general occurrence rate on various level of FEP was obviously higher than that of the control group. The highest occurrence rate of 208.32% and 58.74% appeared when the FEP value was between 0.36 mumol/L to 0.54 mumol/L. When we made the comparison according to different symptoms as headache, dizziness, hypomnesis, somnipathy, palpitation and ephidrosis, the occurrence rate of headache was distinctively highger than that of the somnipathy.

Adult↗
PubMed2000

[An experimental study on the relationship between early postmortem intervals and DNA content of spleen cells in rats by computerized image analysis].

15 rats were used in this experiment. After the rats were executed, spleen cells were collected and smeared in every hour within 24 hours, then fixed with formalin solution and stained with Feulgen's method. Mean and integral optical density and abnormal index of cell DNA were measured with a auto-TV-image system, and the data were statistically analyzed. Results showed that the DNA degeneration rate of rat spleen cells had a linear relationship with early postmortem intervals.

Animals↗
PubMed2000

[An experimental study on the relationship between the estimation of early postmortem interval and DNA content of liver cells in rats by image analysis].

15 rats were used in this experiment. After rats were killed, cells of liver were collected, smeared, fixed with Formalin in every hour within the first 24 hours then stained with Feulgen's method, With an auto-TV-image system, mean and integral optical density and abnormal index of cell DNA were measured and analyzed statistically. The results showed that the DNA degeneration rate of liver cells had a linear relationship to early postmortem period in rats.

Animals↗
PubMed2000

[Immobilization osteoporosis and fracture in children].

This study was intended to enhance the diagnostic vigilance of immobilization osteoporosis with fracture and explore its prevention and treatment. Thirteen children with the hip disease underwent one to nine months of plaster cast after operation. A retrospective analysis was made on these 13 patients with fracture and immobilization osteoporosis. The result showed that disuse fracture occurred in fifteen places of their femora. All of these cases were cured by non-operative and drug treatment. These data suggest that for the cases of immobilization osteoporosis it is important to prevent fracture by means of early diagnosis, proper drugs, early function exercise, appropriately shorter period of fixation and the avoidance of trauma.

Child↗
PubMed2000

[Cloning and expression of the gene encoding maltoologosyl trehalose synthase from Sulfolobus shibatae in E. coli].

2.2 kb DNA fragment encoding a novel enzyme, maltooligosyl trehalose synthase (MTSase) was amplified from Sulfolobus shibatae by using PCR technique. The amplified 2.2 kb DNA fragment was inserted into an expression vector, pBV220, to yield the recombinant plasmid pSBGT1. MTSase gene in pBSGT1 was expressed in E. coli. The molecular weight of expressed MTSase detected by SDS-PAGE was about 74 kD, which is conformed with that deduced from nucleotide sequence. The expressed MTSase protein accounted for about 4.4% of the total cell protein. The MTSase from transformants containing pBSGT1 is capable of decreasing DE value, forming non-reducing or less-reducing saccharides when allowed to act on reducing partial starch hydrolysates.

Cloning, Molecular↗
PubMed2000

[Cloning and expression of the gene encoding novel alpha-amylase from Sulfolobus shibatae in E. coli].

A novel alpha-amylase gene was amplified from Sulfolobus shibatae by using PCR technique. The amplified 1.7 kb DNA fragment was inserted into an expression vector pBV220 to yield the recombinant plasmid pSBAM. The novel alpha-amylase gene in pSBAM was expressed in E. coli. The production of the novel alpha-amylase activity reached over 8 units/100 mL of the culture. The molecular weight of this enzyme was about 61 kD by SDS-PAGE. The expressed novel alpha-amylase protein in E. coli DH5 alpha accounted for about 20% of the total protein in the recombinant cell. The cooperative action of the novel alpha-amylase and the maltooligosyltrehalose synthase from Sulfolobus shibatae was investigated and trehalose was detected by using HPLC analysis when using amylose and partial starch hydrolysates as substrates.

Cloning, Molecular↗
PubMed2000

[Analysis of trace elements in liver, spleen and brain of rats infected with Toxoplasma gondii].

OBJECTIVE: To study the level of five trace elements(Fe2+, Cu2+, Zn2+, Ca2+, Mg2+) in the liver, spleen and brain of the rats infected with Toxoplasma gondii. METHODS: 20 rats were randomly and equally divided into two groups: normal group and experimental group. On the 64th day after injection of 1.5 x 10(6) T. gondii/2 ml, all of the rats were killed and the atomic absorption method were used. RESULTS: Compared with the normal group, the level of Cu2+ in liver in experimental group was significantly reduced (P < 0.01), and the amount of Fe2+ of sick rats were higher than that of the normal (P < 0.01). No differences in the content of Zn2+, Ca2+, Mg2+ between the experimental and control group were determined; the level of Fe2+, Cu2+ in spleen in experimental group was significantly altered (P < 0.01). The amount of Mg2+ of sick rats were higher than that of the normal (P < 0.01), and no difference on the content of Zn2+, Ca2+ between the experimental and control group were estimated; the level of Fe2+, Cu2+, Mg2+ in brain in experimental group was significantly reduced (P < 0.01). The amount of Ca2+ of sick rats were higher than that of the normal (P < 0.02). No difference on the content of Zn2+ between the experimental and control group were estimated. CONCLUSION: T. gondii infection might cause changes in trace elements in the liver, spleen and brain of rats.

Animals↗
PubMed2000

[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↗
PubMed2000

[Microsatellite instability in urine sediments from patients with transitional cell carcinoma of bladder and its clinical value].

OBJECTIVE: To investigate the expression of microsatellite instability in transitional cell carcinoma of bladder and to detect its diagnostic value. METHODS: Urine samples from 35 patients with transitional cell carcinoma of bladder (TCC) were analyzed by PCR method. 25 patients were followed up to detect microsatellite instability in their urine sediments. RESULTS: Microsatellite changes (including MSI and LOH) were detected in 88.6% of urine sediments (31 of 35 patients). Microsatellite changes were detected in urine sediments of 10 of 12 patients with tumor recurrence, in which the existence of tumor cells in the urine of 3 patients had been correctly predicted before cystoscopic evidence from 3 to 6 months. CONCLUSION Microsatellite analysis of urine sediment may be a novel and potentially clinical tool for the diagnosis and follow-up of bladder cancer patients.

Adult↗
PubMed2000

[The determination of ofloxacin by fluorescence spectrophotometry].

This paper reports the assay of ofloxacin by fluorescence spectrophotometry. The fluorescence strength of ofloxacin is proportional to its concentration within the range from 0.500-25.0 ppm. The linear regression coefficient equals to 0.9999, and the recovery ratio is 99.0%. The results of determination for the samples of ofloxacin capsule from China and Japan are very close to that determined by the ultraviolet spectrophotometry, there isn't any obviously difference which was examined by Student's test. This method is both simplicity and accuracy, also it needs only one kind of reagent. It's believable that this method would be suitable for the use in clinical medicine and pharmaceutical industry.

Anti-Infective Agents↗