Biomedical subjects

X L Liang

Publications and source records attributed to X L Liang.

8 recordsLinked to original sources

PubMed2004

Performing probe experiments in the SEM.

A four nanoprobe system has been installed inside a FEI XL30 F scanning electron microscope (SEM), and shown to be fully compatible with the normal functions of the SEM and also a Gatan cold stage (model C1003, -185-400 degrees C). With some selected examples of applications, we have shown that this nanoprobe system may be used effectively for gripping, moving and manipulating nanoobjects, e.g. carbon nanotubes, setting up electric contacts for electronic measurements, tailoring the structure of the nanoobject by cutting, etc. and even for making unexpected nanostructures, e.g. a nanohook. Applications in other areas have also been speculated, limitations or disadvantages of the current design of the probe system were discussed, and methods for possible improvement were suggested.

Journal Article↗

PubMed2001

Copper transportion of WD protein in hepatocytes from Wilson disease patients in vitro.

AIM: To study the effect of copper transporting P-type ATPase in copper metabolism of hepatocyte and pathogenesis of Wilson disease (WD). METHODS: WD copper transporting properties in some organelles of the cultured hepatocytes were studied from WD patients and normal controls.These cultured hepatocytes were incubated in the media of copper 15 mg x L(-1) only, copper 15 mg x L(-1) with vincristine (agonist of P-type ATPase) 0.5mg x L(-1), or copper 15 mg x L(-1) with vanadate (antagonist of P-type ATPase) 18.39 mg x L(-1) separately. Microsome (endoplasmic reticulum and Golgi apparatus), lysosome, mitochondria, and cytosol were isolated by differential centrifugation. Copper contents in these organelles were measured with atomic absorption spectrophotometer, and the influence in copper transportion of these organelles by vanadate and vincristine were comparatively analyzed between WD patients and controls. WD copper transporting P-type ATPase was detected by SDS-PAGE in conjunction with Western blot in liver samples of WD patients and controls. RESULTS: The specific WD proteins (M(r)155,000 lanes) were expressed in human hepatocytes, including the control and WD patients. After incubation with medium containing copper for 2 h or 24 h, the microsome copper concentration in WD patients was obviously lower than that of controls, and the addition of vanadate or vincristine would change the copper transporting of microsomes obviously. When incubated with vincristine, levels of copper in microsome were significantly increased, while incubated with vanadate, the copper concentrations in microsome were obviously decreased. The results indicated that there were WD proteins, the copper transportion P-type ATPase in the microsome of hepatocytes. WD patients possessed abnormal copper transporting function of WD protein in the microsome, and the agonist might correct the defect of copper transportion by promoting the activity of copper transportion P-type ATPase. CONCLUSION: Copper transportion P-type ATPase plays an important role in hepatocytic copper metabolism. Dysfunction of hepatocytic WD protein copper transportion might be one of the most important factors for WD.

Adenosine Triphosphatases↗

PubMed2001

[Study on syndrome pattern in insulin resistant model rats].

OBJECTIVE: To explore the Syndrome pattern in insulin resistant model rats. METHODS: Eight Sprague-Dawley (SD) rats were induced to insulin resistance (IR) by 60% high-sucrose forage. RESULTS: The correlative co-efficient of some biological and internal changes were clusterly analyzed and divided into 3 groups, which was closely related with phleg tubidity, blood stasis and internal toxin types respectively. The phlegm turbidity type was characterized by high content of blood lipid (triglyceride, total cholesterol) and high concentration of glycated serum protein; the blood stasis type was characterized by tendency of high viscosity and high coagulant state, the blood pressure increased, prothrombin time shortened, fibrinogen content raised and RBC and platelet count increased; while the internal toxin type was characterized by high content of glucose, insulin and the elevation of tumor necrosis factor. CONCLUSION: The combined Syndrome of phlegm turbidity, blood stasis and internal toxin is the Syndrome-pattern in insulin resistant model rat. This observation provides theoretic basis for clinical and experimental studies of TCM.

Animals↗

PubMed2001

[Effect of stilbene polymer (Gn-3) on experimental liver injuries in mice].

AIM: To study the protective effect of Gn-3 (a stilbene polymer isolated from Gnetum parvifolium) against liver injury induced by CCl4, N-acetyl-p-aminophenol (APAP) and Bacillus Calmette-Guerin (BCG) plus bacterial lipopolysaccharide (LPS) in mice. METHODS: The experimental model of liver injury were induced by 0.1% CCl4 i.p. (10 mL.kg-1.d-1 for 3d), APAP i.p. (150 mg.kg-1) or BCG (5 mg) plus LPS (7.5 micrograms) in mice. The levels of ALT in serum, MDA and GSH in liver tissues were detected. The histopathologic changes were observed by light microscope. RESULTS: Gn-3 was shown to markedly reduce the elevated serum ALT levels, liver tissue MDA and improve the histopathological changes in all the three experimental liver injury models. No effect of Gn-3 was observed on the liver GSH level in liver injury mice. CONCLUSION: Gn-3 was found to inhibit the development of liver injury caused by CCl4, APAP, or BCG plus LPS. This means that Gn-3 has liver protective effects.

Acetaminophen↗

PubMed1999

Embryonic hemoglobins are expressed in definitive cells.

Human embryonic zeta and epsilon globin chains are synthesized in yolk sac-derived primitive erythroid cells, and decrease rapidly during definitive erythropoiesis. Examination of zeta and epsilon globin expression at the cellular level using dual-color immunofluorescence staining with specific monoclonal antibodies showed that embryonic globin proteins are present in definitive erythroid cells. More than half of fetal erythrocytes were positive for zeta and approximately 5% for epsilon globin. Approximately one third of newborn red blood cells were zeta-positive and less than 1% epsilon-positive. Adult erythrocytes did not have embryonic globins. Erythroblasts that developed in liquid cultures also contained embryonic globin in amounts which declined with ontogenic age, and the proportion of positive cells in vitro was less than in the comparable erythrocytes that developed in vivo. Thus, embryonic globin chains are synthesized in definitive erythroid cells and decrease with ontogeny. Modulation of embryonic globin gene expression is not solely due to a switch from primitive to definitive erythropoiesis.

Adult↗

PubMed1996

Cloning and characterization of the mouse alpha globin cluster and a new hypervariable marker.

A 95-kb region of the mouse genome spanning the entire alpha-globin gene cluster was isolated as overlapping cosmid clones and characterized. In addition to the embryonic (zeta) and adult (alpha) genes, the cloned contig contains the complete N-methylpurine-DNA glycosylase (MPG) gene, the alpha-globin-positive regulatory element (mHS-26), and a previously unidentified hypervariable region (named the mouse alpha-HVR). In mice, the distance between the MPG gene and mHS-26 is approximately 18 kb; between the mHS-26 and the zeta-gene, approximately 26 kb; from the zeta-gene to the 5' end of the alpha-gene, approximately 16 kb; and the two alpha-genes are separated by approximately 12 kb. In human, the corresponding distances are approximately 27 kb, approximately 40 kb, approximately 19 kb, and approximately 3 kb respectively. The alpha-HVR is located approximately 18 kb upstream of the mouse zeta-globin gene transcription start site and contains a variable copy number tandem repeat (VNTR) array of a 35-bp sequence rich in (G+C) content. The unit sequence of the HVR shares the short core sequence with the HVRs identified in the human alpha-gene cluster. Thus, this HVR may be a valuable evolutionary marker, as well as a useful genetic marker for the mouse.

Animals↗

PubMed1987

Environmental factors in the etiology of Parkinson's disease.

Parkinson's disease (PD) has been proposed to result from the interaction of aging and environment in susceptible individuals. Defective metabolism of debrisoquine, inherited as an autosomal recessive, has been associated with this susceptibility. In 35 PD patients and 19 age-matched controls, no significant differences in debrisoquine metabolism were found, although a trend to impaired metabolism was noted in patients with disease onset less than or equal to 40. Foci of PD patients were associated with rural living and well water drinking, or rural living coupled with market gardening or wood pulp mills. In a questionnaire survey, patients with PD onset less than or equal to age 47 were significantly more likely to have lived in rural areas and to have drunk well water than those with onset greater than or equal to age 54 (p less than or equal to 0.01). Because of population mobility in North America, a case-control study designed to test environmental, occupational, dietary and other proposed risk factors for PD was conducted in China, where the population is more stationary and the environment more stable. No significant differences in incidences of head trauma, smoking or childhood measles were found between patients and controls.

Adult↗

PubMed1986

[Serum beta 2-microglobulin and carcinoembryonic antigen in patients with bronchogenic carcinoma].

In patients with bronchogenic carcinoma of various types and stages, serum beta 2-microglobulin (beta 2-M) and carcinoembryonic antigen (CEA) were assayed simultaneously. The concentrations of serum beta 2-M and CEA were found to be statistically related to complete remission of the tumor (P less than 0.01). But it was also found that there was no correlation between the levels of beta 2-M and CEA (r = 0.0621). In follow-up, the CEA was found to be increasing incessantly as the disease progressed. For the level of serum beta 2-M, as the patients' condition got worse, it first rose, then dropped and became markedly lower before the patient died. The serum beta 2-M was often elevated 3-5 months earlier than CEA, and frequently resumed the normal level later than CEA after the carcinoma had a complete remission. With the progression of the bronchogenic carcinoma, elevation of beta 2-M was not necessarily a sign of poor prognosis. In contrast, with the serum beta 2-M markedly lowered after an initial elevation, the serum CEA became elevated, the prognosis was usually poor. The authors believe that, in patients with lung cancer, CEA produced from the lung cancer cells would give a level fluctuating with the size of the primary focus and the extent of the metastasis. But its positive rate is rather low. The serum beta 2-M is produced indirectly by certain immunologic function against bronchogenic carcinoma or its metabolites and not by the cancer cells directly. The positive rate of beta 2-M is high, so slightly is its false positive rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗