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Biomedical subjects

X J Liu

Publications and source records attributed to X J Liu.

At least 91 records · Page 5Linked to original sources
PubMed1993

99mTc-antimyosin antibody imaging for the detection of acute myocardial infarction in human beings.

111In-antimyosin imaging is a highly sensitive and specific technique for the detection of myocardial necrosis. Two new methods of labeling antimyosin with 99mTc have been developed, and were compared with the standard 111In-antimyosin imaging technique in 29 patients with acute myocardial infarction. Fourteen patients (group I) received directly labeled 99mTc-antimyosin, and 15 (group II) were given RP-1 conjugated 99mTc-antimyosin. 99mTc-antimyosin imaging was performed at 6, 12, and 24 hours, and 111In-antimyosin imaging was done at 24 and 48 hours following injection. The images were interpreted by three blinded observers. In group I, 99mTc-antimyosin uptake could be detected in 3, 6, and 12 cases at 6, 12, and 24 hours, respectively, compared with only 8 cases at 24 hours with 111In-antimyosin. At 48 hours all patients showed 111In-antimyosin uptake. In group II, 99mTc-antimyosin uptake could be detected in 2, 3, and 6 cases at 6, 12, and 24 hours, respectively, compared with 8 and 12 cases at 24 and 48 hours, respectively, with 111In-antimyosin. Gated blood pool studies could be obtained in all patients following 99mTc-antimyosin injection and could be used to identify regional wall motion abnormalities. The plasma half-lives of 99mTc-antimyosin in group I and group II were 2.67 +/- 0.3 hours and 4.23 +/- 0.3 hours, respectively, and the plasma half-life of 111In-antimyosin was 6.3 +/- 0.4 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Rate of change of left ventricular ejection fraction during exercise is superior to the peak ejection fraction for predicting functionally significant coronary artery disease.

OBJECTIVE: To detect and characterise rapid temporal changes in the left ventricular response to exercise in patients with ischaemic heart disease and to relate these changes to the functional severity of coronary artery disease. BACKGROUND: The gamma camera does not allow the detection of rapid changes in cardiac function during exercise radionuclide ventriculography, the monitoring of which may improve the assessment of patients with ischaemic heart disease. METHODS: A miniature nuclear probe (Cardioscint) was used to monitor continuously left ventricular function during exercise in 31 patients who had coronary angiography for suspected coronary artery disease. A coronary angiographic jeopardy score was calculated for each patient. RESULTS: The coronary jeopardy score ranged from 0 to 12 (median 4). Ejection fraction fell significantly during exercise from 46% to 34%. Patients were divided into two groups based on the response of their ejection fraction to exercise. In 14 patients (group I), the peak change in ejection fraction coincided with the end of exercise, whereas in the other 17 patients (group II) the peak change in ejection fraction occurred before the end of exercise, resulting in a brief plateau. The peak change in ejection fraction and the time to its occurrence were independent predictors of coronary jeopardy (r = -0.59, p < 0.001 for peak change and r = -0.69, p < 0.001 for time to that change). The rate of change in ejection fraction was the strongest predictor of coronary jeopardy (r = -0.81, p < 0.001). In group I the peak change in ejection fraction was a poor predictor severity of coronary disease (r = -0.28, NS), whereas the time to peak and the rate of change in ejection fraction were good predictors (r = -0.65 and r = -0.73, p < 0.01). In group II the peak, the time to the peak, and the rate of change in ejection fraction were good predictors of coronary jeopardy (r = -0.75, r = -0.61, and r = -0.83, p < 0.01). CONCLUSION: The rate of change of ejection fraction during exercise can be assessed by continuous monitoring of left ventricular function with the nuclear probe, and is the best predictor of functionally significant coronary artery disease.

Adult↗
PubMed1993

Development of specific antibodies to rat insulin-like growth factor-binding proteins (IGFBP-2 to -6): analysis of IGFBP production by rat granulosa cells.

Six insulin-like growth factor-binding proteins (IGFBPs) have been isolated and their cDNAs cloned in the rat and human species. The next step is to develop antibodies to each IGFBP. Toward this goal, we generated rabbit polyclonal antibodies to rat IGFBP-2, -4, -5, and -6, using synthetic peptide fragments of the IGFBPs. A rat IGFBP-3 polyclonal antibody was prepared in a previous study using the native protein. Western immunoblotting demonstrated that the IGFBP-2, -3, -4, -5, and -6 antibodies were highly specific for their respective antigens. The elicited antisera were used to study IGFBP production in primary cultures of rat granulosa cells grown in serum-free medium for 72 h. Ligand blotting with 125I-labeled IGF-I and IGF-II revealed two bands migrating at 29 and 24 kilodaltons (kDa) in the medium of untreated control cells, whereas no bands were detectable in medium from cells incubated with 100 ng/ml FSH. Western blotting of control medium with all of the IGFBP antibodies revealed that the IGFBP-4 antibody stained two bands at 28 and 24 kDa, and the IGFBP-5 antibody stained two bands at 30 and 29 kDa. By contrast, these bands were absent in medium from FSH-stimulated cells; instead, two lower molecular mass bands of 21.5 and 17.5 kDa were detected with the IGFBP-4 antibody, and a 21-kDa band was seen with the IGFBP-5 antibody. The same 21.5- and 17.5-kDa bands were seen when exogenously added IGFBP-4 was incubated with the FSH-conditioned medium, whereas untreated medium did not degrade the added IGFBP-4. Incubation with the conditioned medium also degraded exogenous IGFBP-5 to yield a 21-kDa band. By contrast, medium from control cells did not degrade the exogenous IGFBP-5. This finding indicates that FSH induced the production of a protease from granulosa cells that degraded IGFBP-4 and -5 in the culture medium. No IGFBPs were detectable in medium from control or FSH-treated cells using the IGFBP-2, -3, and -6 antibodies. Northern blotting analysis of the same control granulosa cell cultures revealed a 2.6-kilobase and a 6.0-kilobase transcript for IGFBP-4 and -5, respectively; however, the IGFBP-4 and -5 mRNAs were essentially undetectable in FSH-treated cell cultures. To determine the effects of the IGFBPs on steroidogenesis, dose-response experiments were performed with IGFBP-4 and -5.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1993

[An observation on the regularity of mould invasion into sugarcane and its prevention].

The factors that influence mould invasion into sugarcane were investigated. Results showed sales pattern, storage condition, and duration of storage for sugarcane were the major influential factors to its mildew. Antiseptic agents had no obvious protective effects on mould invasion. According to authors' experiments, sugarcane can be stored for no more than 3 weeks to prevent from mildew. The outward appearance of sugarcane changed with its contamination of 3-NPA. A simple method for detecting mildew in sugarcane was also described in the paper.

Food Microbiology↗
PubMed1993

Effects of triptonide on mouse immune functions.

Triptonide (Tri) extracted from Tripterygium wilfordii Hook inhibited the proliferation of mouse splenocytes induced by suboptimal concentration of concanavalin A or lipopolysaccharide at concentrations of 0.02, 0.1, and 0.5 microgram.ml-1. It showed a suppressive effect on one way mixed lymphocyte culture (MLC) at 0.1-0.4 microgram.ml-1. The lymphocytes harvested from the first Tri (0.4 microgram.ml-1)-containing MLC inhibited the second MLC after being washed and irradiated with 60Co source (30 Gy). Serum anti-sheep red blood cell antibody (hemolysin) formation and clearance of charcoal particles were also suppressed by Tri in vivo. Although delayed hypersensitivity (DH) reaction to dinitrofluorobenzene (DNFB) was inhibited by Tri 1.2, 2.5, and 5.0 mg.kg-1 (ip, qd x 5 d), the spleen cell interleukin-2 secretion activities of these mice were not suppressed. Graft vs host reaction (GVHR) was not inhibited by Tri 2.5 and 5.0 mg.kg-1 (ig, qd x 5 d). Helper T cells (Th)/suppressor T cells (Ts) ratio was reduced at 2.5 mg.kg-1. The effects of Tri on mouse thymus and spleen weight were related to the age. Tri (1.2, 2.5, 5.0 mg.kg-1) had no effect on thymus and spleen weights in 8-wk-old mice. However, it increased the thymus and spleen weights in 12-wk-old mice at doses of 1.2 and 2.5 mg.kg-1. The data indicated that Tri had extensive suppressive effects on mouse immune function and its mechanism may be related to the reduction of Th/Ts ratio and the induction of Ts cells.

Animals↗
PubMed1993

[Effect of Equisetum hyemale on experimental hyperlipemia in rats and its toxic test].

The results of an experimental study in rats fed with Equisetum hyemale and hyperlipid food have proved that inhibiting effects on the elevation of triglyceride and cholesterol can be obviously observed in both high and low doses of Equisetum. The study also shows that Equisetum hyemale can antagonize the hyperlipemia in rats. The acute toxic test has proved its low toxicity.

Animals↗
PubMed1992

Quantitative 111In antimyosin antibody imaging to predict the age of myocardial infarction.

To establish whether quantitative 111In antimyosin uptake can be used to predict infarct age, we studied the heart-lung ratio in 107 images from 90 patients at various intervals following a Q-wave infarction. Imaging was performed 24 hours following 111In antimyosin injection. The HLR was measured as the ratio of the maximum counts in the infarcted myocardium to the adjacent lung background. The ratio ranged from 1.26 to 3.87, and declined with increasing infarct age. Infarcts were classified on the basis of age as type I (less than 3 days old), type II (less than 14 days), and type III (less than 90 days). True positive and false positive rates (TPR and FPR), and test-likelihood ratio calculations were performed for HLR thresholds ranging from 1 to 4, for the three infarct types. A FPR of 0% and likelihood ratio of infinity was obtained at a HLR threshold of 2.3 for type I infarcts (TPR 40.8%); at a HLR threshold of 2 for type II infarcts (TPR 50.6%), and a threshold of 1.8 for type III infarcts (TPR 52.6%). The likelihood of each infarct type can be estimated directly from the HLR for values below the above thresholds. These results show that quantitative 111In-antimyosin imaging may be used to predict infarct age.

Antibodies, Monoclonal↗
PubMed1992

Spontaneous variability of left ventricular ejection fraction assessed with the Cardioscint.

A miniature, non-imaging caesium iodide nuclear probe optically coupled to a photodiode (the 'Cardioscint') has been developed which, in conjunction with a modified personal computer, is capable of continuous on-line monitoring of left ventricular function and ST-segment level at the bedside. The purpose of this study was to assess the variability in ejection fraction over periods of time and to compare this variability with that of equilibrium gamma camera radionuclide ventriculography. Ten normal volunteers (nine male) of mean (S.D.) age 49 (10) years underwent semisupine radionuclide ventriculography using both gamma camera and Cardioscint in randomized order. The gamma camera recorded four consecutive acquisitions (mean of 7.2 min each) and the Cardioscint, using a 20 s acquisition time, recorded left ventricular function over 35 min per subject. The mean ejection fraction of the group by gamma camera was 52 (7)% and by Cardioscint was 54 (5)%. When the variability in ejection fraction by gamma camera was compared with the Cardioscint averaged over corresponding time periods (i.e. an average of 7.2 min), the mean coefficient of variation of the camera was 5.0% versus 2.9% for the probe system. Individual 20-s probe acquisitions over the total study duration (reflecting the short-term variability of the system) had a coefficient of variation of 5.1%. Thus the Cardioscint provides a stable continuous recording of ejection fraction. These volunteer data provide a basis for interpretation of data acquired in the clinical situation.

Adult↗
PubMed1992

[Relation between left ventricular mass indexes and cardiac function in hypertensive patients: an approach with Doppler echocardiography].

73 age-matched hypertensive patients, 46 men and 27 women, were divided into the four groups according to left ventricular mass indexes (LVMI) and normal control groups were established correspondingly. Doppler and M-mode echocardiography were used to assess the systolic and diastolic functions of left ventricle (LV) and the alterations of heart construction. It was shown that when the LVMI increased slightly, the internal dimension and systolic function of LV had no significant change, but the diastolic function became abnormal and the left atrium enlarged. When the LVMI increased significantly, both the left atrium and left ventricle enlarged and the systolic and diastolic functions of LV were impaired. It is concluded that increase of LV mass may be present in the early stage of hypertension and left atrial enlargement is an early sign of left ventricular diastolic dysfunction, which occurs before systolic dysfunction in the patients with essential hypertension.

Aged↗
PubMed1992

Clinical evaluation of 99Tcm-MIBI SPECT in the assessment of coronary artery disease.

To evaluate the clinical efficacy of 99Tcm-MIBI myocardial tomography for detecting coronary artery disease (CAD) 115 consecutive patients who underwent both 99Tcm-MIBI single photon emission computed tomography (SPECT) and coronary arteriography were studied. Thirty-three patients without and 82 with significant coronary artery disease were documented by coronary arteriography. The overall sensitivity and specificity of 99Tcm-MIBI SPECT for detecting coronary artery disease were 96 and 87.9%, respectively. The sensitivity for identifying patients with CAD without myocardial infarction was 88%. The sensitivity of 99Tcm-MIBI SPECT for detecting individual coronary artery lesions was 86% for left anterior descending artery (LAD), 69% for left circumflex artery (Lcx) and 86% for right coronary artery (RCA), lesions respectively. In conclusion, 99Tcm-MIBI SPECT provides a reliable method for detecting CAD.

Adult↗
PubMed1991

Identification and structural characterization of further DNA elements in the potato and pepper genomes homologous to the transposable element-like insertion Tst1.

The molecular cloning and nucleotide sequence of elements from potato and pepper that are related to the recently identified Tst1 element are described. Sequence analysis reveals considerable conservation of sequences internal to both the Tst1 element and two of the related elements identified here. In six potato clones analysed, the 11 bp inverted repeat first identified in the Tst1 element is conserved. Several of the elements are flanked by an 8 bp direct repeat. DNA fragments which were amplified from several pepper genomes by polymerase chain reaction (PCR) amplification using the inverted repeat as sequence primers also display considerable conservation of sequences internal to the Tst1 element. These data further support the possibility that Tst1 is a non-autonomous transposable element and that Tst1 might be the first example of a transposable element which occurs in several genera of solanaceous plants.

Base Sequence↗
PubMed1991

111In antimyosin antibody uptake is related to the age of myocardial infarction.

The intensity of 111In antimyosin uptake is related to the type (Q wave or non-Q wave), size, and location of an acute myocardial infarction. To determine whether the uptake intensity is also related to the infarct age, and to establish the time frame during which 111In antimyosin uptake occurs postinfarction, we studied a quantitative measure of uptake intensity, the heart-lung (HL) ratio, in 90 consecutive patients at various intervals following a Q wave infarction. Imaging was performed 24 hours following 111In antimyosin injection. Uptake of antimyosin could be demonstrated up to 154 days postinfarction. The HL ratio was measured as the ratio of the maximum counts in the infarcted myocardium to the adjacent lung background, and was 1.93 +/- 0.51 (mean +/- SD) overall. The ratio declined exponentially with increasing age of infarct. Using nonlinear regression analysis, 47% of the total variance of the HL ratio could be attributed to age alone (p less than 0.001). Sequential antimyosin imaging was performed in nine patients, with the first study between 4 and 15 days, the second between 50 to 100 days, and the third between 125 to 270 days after the onset of chest pain. The HL ratios were (mean +/- SD) 1.77 +/- 0.25 for scans between 4 and 15 days, 1.54 +/- 0.12 for scans between 50 and 100 days (p less than 0.02), and 1.42 +/- 0.16 (p less than 0.05) for scans between 125 to 270 days, further establishing the progressive reduction in 111In antimyosin uptake with age of myocardial infarction.

Adult↗
PubMed1991

[Preparation of rotundine-chitosan gelled granules and their drug-release tests].

The paper described a delivery system prepared from granulation of a chitosan solution containing rotundine in a coagulating bath and examined the effects of the ratios of rotundine: chitosan, crosslinking agents and molecular weight of chitosan on the analgesic release rate. It was shown that the rotundine (56.7%)-chitosan (Mw:5.70 x 10(5) degree of deacetylation: 72.4%) gelled granules in an artificial gastroenteric juice (pH 1.0 and 7.2) have T50 of 40 and 180 min respectively, and the total release time sustained over 540 min.

Alkaloids↗
PubMed1991

Filariasis and its control in Fujian, China.

Epidemiological survey of filariasis in Fujian Province, China showed that malayan filariasis, transmitted by Anopheles lesteri anthropophagus was mainly distributed in the northwest part and bancroftian filariasis with Culex quinquefasciatus as vector, in middle and south coastal regions. Both species of filariae showed typical nocturnal periodicity. Involvement of the extremities was not uncommon in malayan filariasis. In contrast, hydrocele was often present in bancroftian filariasis, in which limb impairment did not appear so frequently as in the former. Hetrazan treatment was administered to the microfilaremia cases identified during blood examination surveys, which were integrated with indoor residual spraying of insecticides in endemic areas of malayan filariasis when the vector mosquito was discovered and with mass treatment with hetrazan medicated salt in endemic areas of bancroftian filariasis. At the same time the habitation condition was improved. These factors facilitated the decrease in incidence. As a result malayan and bancroftian filariasis were proclaimed to have reached the criterion of basic elimination in 1985 and 1987 respectively. Surveillance was pursued thereafter and no signs of resurgence appeared.

Animals↗