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Biomedical subjects

Q S Li

Publications and source records attributed to Q S Li.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Abdominal bipedicled subepidermal vascular-network flap in repair of degloving injury of hand].

OBJECTIVE: To evaluate the clinical result of repairing degloving injury of hand with abdominal bipedicled subdermal vascular-network flap in emergence. METHODS: From 1994 to 1997, 19 cases with degloving injury of hand were treated with two flaps, one flaps with the inferior epigastric artery as pedicle, another with superficial epigastric artery. The two skin flaps were designed oppositely to cover the injured hands. RESULTS: All the flaps survived. Followed up for 1 to 3 years, the contour of hands were fine. Extension of fingers was normal and opponers of thumbs was good. Range of flexion of metacarpo-phalangeal joints was from 45 to 60 degrees, and the proximal interphalangeal joints was from 10 to 25 degrees. CONCLUSION: For the subdermal vascular network, the bipedicled flaps of abdomen in repair of degloving injury of hand have sufficient blood supply, strong resistance to infection, high survival rate, and good contour.

Adolescent↗
PubMed1998

Polynucleotide phosphorylase is a component of a novel plant poly(A) polymerase.

We have isolated cDNA clones encoding a novel RNA-binding protein that is a component of a multisubunit poly(A) polymerase from pea seedlings. The encoded protein bears a significant resemblance to polynucleotide phosphorylases (PNPases) from bacteria and chloroplasts. More significantly, this RNA-binding protein is able to degrade RNAs with the resultant production of nucleotide diphosphates, and it can add extended polyadenylate tracts to RNAs using ADP as a donor for adenylate moieties. These activities are characteristic of PNPase. Antibodies raised against the cloned protein simultaneously immunoprecipitate both poly(A) polymerase and PNPase activity. We conclude from these studies that PNPase is the RNA-binding cofactor for this poly(A) polymerase and is an integral player in the reaction catalyzed by this enzyme. The identification of this RNA-binding protein as PNPase, which is a chloroplast-localized enzyme known to be involved in mRNA 3'-end determination and turnover (Hayes, R., Kudla, J., Schuster, G., Gabay, L., Maliga, P., and Gruissem, W. (1996) EMBO J. 15, 1132-1141), raises interesting questions regarding the subcellular location of the poly(A) polymerase under study. We have reexamined this issue, and we find that this enzyme can be detected in chloroplast extracts. The involvement of PNPase in polyadenylation in vitro provides a biochemical rationale for the link between chloroplast RNA polyadenylation and RNA turnover which has been noted by others (Lisitsky, I., Klaff, P., and Schuster, G. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 13398-13403).

Amino Acid Sequence↗
PubMed1998

Characterization of a cDNA encoding a novel plant poly(A) polymerase.

We have isolated cDNA clones encoding a novel factor (PAP-I) that is a component of a multi-subunit poly(A) polymerase from pea seedlings. The encoded protein, when isolated from appropriately engineered Escherichia coli, was active as a poly(A) polymerase, either with an associated RNA binding cofactor (PAP-III) or with free poly(A) as an RNA substrate. The latter observation indicates that PAP-I is in fact a poly(A) polymerase. PAP-I bore a striking resemblance to an as yet uncharacterized cyanobacterial protein. This observation suggested a possible chloroplast localization for PAP-I. This hypothesis was tested and found to be substantiated; immunoblot analysis identified PAP-I in chloroplast but not nuclear extracts. Our results suggest that PAP-I is a component of the machinery that adds poly(A) to chloroplast RNAs.

Amino Acid Sequence↗
PubMed1998

[Decrease of cAMP and increase of amino acids contents in mouse brain after dihydroetorphine tolerance].

AIM: To study the mechanism of dihydroetorphine (DHE) tolerance. METHODS: DHE tolerance was produced by repeated s.c. injections in progressively increased doses to mice for 8 d. The concentrations of amino acids and cAMP were detected by RP-HPLC/fluorescence assay and radioimmunoassay, respectively. RESULTS: The basal contents of glutamic acid (Glu), aspartic acid (Asp), and GABA in whole brain (cerebellum removed) were increased respectively from 14.1 +/- 2.1, 3.0 +/- 0.4, and 1.8 +/- 0.8 mumol/g tissue in control mice to 17.2 +/- 2.2, 4.1 +/- 0.6, and 3.2 +/- 1.0 mumol/g tissue in tolerant mice, and the rates of increase were 22.0% (P < 0.05), 36.7% (P < 0.01), and 77.8% (P < 0.05 vs control), respectively. There was no significant difference in the basal contents of Gln (5.1 +/- 1.0 vs 4.5 +/- 1.7 mumol/g tissue of control). The basal contents of cAMP in hypothalamus and striatum were decreased respectively from 271 +/- 38 and 189 +/- 31 nmol/g tissue in control mice to 96 +/- 15 and 65 +/- 21 nmol/g tissue in tolerant mice (P < 0.01), and the rates of decrease were 64.6% and 65.6%, respectively. There was no significant difference of cAMP in cerebral cortex (72 +/- 20 vs 55 +/- 15 nmol/g tissue of control). CONCLUSION: The increases of Glu, Asp, and GABA in brain and the decrease of cAMP in hypothalamus and striatum were involved in DHE tolerance.

Amino Acids↗
PubMed1996

A plant poly(A) polymerase requires a novel RNA-binding protein for activity.

We have purified a novel factor (PAP-III) that is a component of a multisubunit poly(A) polymerase from pea seedlings. This factor consists of one or more polypeptides with molecular masses of about 105 kDa and of a population of associated RNAs that can serve as substrates for polyadenylation. When these RNAs are separated from the 105-kDa polypeptides, polyadenylation becomes dependent upon exogenously added RNA. This RNA-dependent activity does not require the presence of a polyadenylation signal in the substrate, indicating that the activity under study is a nonspecific polyadenylation activity. One or more of the 105-kDa polypeptides could be cross-linked to the products of polyadenylation labeled with [alpha-32P]ATP and to exogenously added labeled RNAs. Cross-linking of the 105-kDa polypeptides to the products of polyadenylation was not affected by the presence of exogenously added competitors, whereas cross-linking to exogenous RNAs was diminished by excesses of RNA homopolymers. Exogenous RNAs could be polyadenylated by the combination of PAP-I + PAP-III, and this activity was diminished if the binding of the exogenous RNAs to PAP-III was prevented. We conclude from these studies that PAP-III is an RNA binding protein, that polyadenylation by the poly(A) polymerase occurs while the substrate RNAs are associated with this protein, and that the pea poly(A) polymerase can only polyadenylate those RNAs that are associated with PAP-III.

Cross-Linking Reagents↗
PubMed1995

Polyphenols from Eriosema tuberosum.

A dichloromethane extract of the roots of Eriosema tuberosum exhibited antifungal activity against Cladosporium cucumerinum and Candida albicans using TLC bioautography. Bioassay-directed fractionation led to the isolation of four new compounds, eriosemaones A-D, together with a known compound, flemichin-D, as the active constituents. Three inactive polyphenols were also isolated after methylation, together with one new chromone, eriosematin. Structures were determined by spectroscopic analysis and from chemical evidence.

Antifungal Agents↗
PubMed1994

Central mechanism of indomethacin analgesia.

The analgesic effect of indomethacin was investigated by using the visceral pain model in rabbits. After intravenous administration of indomethacin (2 mg/kg), the maximum increase of the visceral pain threshold was 0.42 +/- 0.31 mA (P < 0.05). The analgesic effect lasted 40 min. After intraventricular microinjection of indomethacin (50 micrograms), the maximum increase of the visceral pain threshold was 0.37 +/- 0.43 mA. After intravenous administration of indomethacin, the content of norepinephrine in perfusates of rabbit fourth ventricle was significantly increased from 18.10 +/- 8.05 to 32.16 +/- 6.15 mg/40 microliters (P < 0.05), compared with data for the control group. The content of beta-endorphin in the perfusate after indomethacin administration was decreased from 5-25 min and slightly increased from 25-35 min, compared with the data for the control group, but there was no significant difference (P > 0.05). Furthermore, intraventricular microinjection of phentolamine (50 micrograms) could block the analgesic effect of an intravenous injection of indomethacin, while naloxone could not. The results imply that prostaglandins of the central nervous system could induce hyperalgesia. Indomethacin injected centrally and peripherally has an analgesic effect on visceral pain. This analgesic effect is mediated by alpha-adrenoceptors. beta-Endorphin does not participate in the analgesic action of indomethacin.

Analgesics↗
PubMed1994

Combined traditional Chinese medicine and Western medicine. Relieving effects of Chinese herbs, ear-acupuncture and epidural morphine on postoperative pain in liver cancer.

In the evaluation of Chinese herbs (A), ear-acupuncture (B) and epidural morphine (C) to relieve postoperative pain and abdominal distension, sixteen male patients with primary liver cancer were observed. This study was conducted by means of orthogonal experiment and double blind, randomized design. The patients received various treatments according to the display of the orthogonal table L16(2)15 which corresponds to 2(3) factorial experiment design. C+ (morphine 2 mg) was given before the peritoneum was sutured. A+ (orally administered) and B+ were given 24 hours after operation. 50-100 mg of pethidine was given when the pain intensity VAS (0-100) exceeded 50-70. The observation parameters included plasma leucine enkephalin (LEK), postoperative total dosage of narcotics administered for 5 days, VAS for pain and pain reliever, abdominal distension, urinary retention, constipation, etc. The results were as follows: a. Patients who had received A (A+B+C+, A+B+C-, A+B-C-, A+B-C+); C (C+A+B+, C+A+B-, C+A-B+, C+A-B-), or B (B+A+C+, B+A+C-, B+A-C+, B+A-C-) produced better analgesic effects than those who had received placebo. The A, B, and C reduced narcotics 650, 450 and 550 mg respectively when compared with placebo. The effects of A and C were of statistical significance (P < 0.05), while AB, BC, and AC interactions were not found; b. A and B minimized abdominal distension and urinary retention, while C prolonged them. As compared with the placebo, A and B accelerated restoration of bowel peristalsis (P < 0.05, ANOVA). Both A and B decreased it for 165 hours, while epidural morphine prolonged it for 49 hours; and c.(ABSTRACT TRUNCATED AT 250 WORDS)

Acupuncture Points↗
PubMed1993

[Detection of CAg in CSF of 231 cerebral cysticercosis patients].

The results of detection of circulating antigen (CAg) in cerebrospinal fluids (CSF) of 231 cerebral cysticercosis patients with McAb (4F8)--based ELISA were reported and compared with the case histories, clinical manifestations and CT scans. No relationship was found between CAg detected in CSF of these cases and history of taeniasis. However, the positive rate of CAg in cerebral cysticercosis patients with subcutaneous nodules was found significantly higher than those in cases with simple cerebral cysticercosis and in cases with subcutaneous nodules disappeared after anti-Cysticercus therapy before CSF collection. The results of CAg detection in CSF were related with the CT findings as well as the stage of the disease. It is thus indicated that McAb (4F8)-based ELISA might be useful not only for diagnosis of neurocysticercosis, but also for the evaluation of efficacy of anti-Cysticercus therapy.

Adolescent↗
PubMed1991

[Hydroelectric shock wave in the treatment of complex urethra obstruction].

Twenty-one patients with traumatic complex urethral obstruction were treated by hydroelectric shock wave (HSW). In the 21 patients, anterior urethral stricture was noted in 3 and posterior urethral obstruction in 18. The length of obstruction was 0.5-6cm. 15 patients were cured by single hydroelectric shock wave, 3 by HSW and electric resection, 2 by HSW with open operation, and 1 failed. The follow-up of 19 patients for 3 to 43 months showed no recurrence of urethral obstruction. The classification of traumatic complex urethral obstruction and the points for attention during treatment of hydroelectric shock wave are discussed.

Adolescent↗
PubMed1991

[Experimental replacement of the trachea by dacron-silicone rubber prosthesis].

Experimental results of trachea replacement by dacron-silicone rubber tube in rabbits and dogs were presented. The techniques for anastomosis of the prosthesis to the host trachea, prevention of obstruction by granulation and the dynamic effects of air current during cough reflex caused by the artificial trachea were also investigated. Experiments showed that the use of artificial trachea with right size (inner diameter) was the key to maintain expectoration mechanism. When the artificial trachea was constructed on proper selected cases, complications resulting from use of Nevilles are preventable.

Anastomosis, Surgical↗
PubMed1991

Tomographic myocardial perfusion imaging with technetium-99m-teboroxime at rest and after dipyridamole.

This study was done to determine whether the rapidly clearing myocardial perfusion agent 99mTc-teboroxime (SQ 30217, Cardiotec) could be combined with tomographic imaging to accurately quantify regional myocardial blood flow distribution in anesthetized dogs. Following stenosis of the anterior descending (LAD, n = 10) or circumflex (LCX, n = 5) coronary arteries, teboroxime was administered simultaneously with radioactive microspheres, at rest and following infusion of dipyridamole (0.15 mg/kg/min x 4 min). Tomographic imaging began 1 min after each teboroxime injection and continued for 12 min. For LAD stenosis, when the dipyridamole study was performed first, teboroxime activity in the center of the ischemic region was closely correlated with tissue microsphere content. However, the severity of the dipyridamole-induced flow deficit was underestimated by teboroxime when the rest study was performed first. Our results show that despite rapid myocardial clearance, tomographic imaging of 99mTc-teboroxime provides reasonably accurate quantitation of dipyridamole-induced anterior wall perfusion defects, but that the flow deficit is underestimated when a rest study is performed first or when the defect is located in the inferior wall.

Animals↗
PubMed1990

Myocardial redistribution of technetium-99m-methoxyisobutyl isonitrile (SESTAMIBI).

To determine whether technetium-99m-hexakis-2-methoxyisobutyl isonitrile (SESTAMIBI) remains fixed in the myocardium following its initial uptake or undergoes time-related redistribution, anesthetized dogs underwent occlusion of the anterior descending coronary artery for 6 min, followed by 3-hr reperfusion. Technetium-99m-SESTAMIBI and thallium-201 (201Tl) were injected intravenously after 1 min occlusion and regional myocardial blood flow was measured with radioactive microspheres. Tomographic imaging of Tc-SESTAMIBI revealed a perfusion defect with slight but definite filling in over 2 hr. Quantitative analysis indicated a significant rise in the nadir and decrease in the width of the defect in circumferential profile curves. After 3-hr of reperfusion, Tc-SESTAMIBI activity in the previously ischemic area was always greater than the activity of microspheres injected during coronary occlusion (mean normalized values, 0.32 versus 0.11, p less than 0.0001). Our results indicate that following transient ischemia and reperfusion, Tc-SESTAMIBI clearly undergoes myocardial redistribution, although more slowly and less completely than 201Tl.

Animals↗
PubMed1989

Parrot breeder's lung: first case report in China.

The authors report the first case of parrot breeder's lung in China and the study of its immunology, respiratory physiology, as well as pathology. The main characteristics of this disease are progressive dyspnea after contacting parrots, patchy or reticular shadows in the lower lung fields on chest X-ray, the presence of alveolitis, accompanied by pulmonary interstitial fibrosis as demonstrated in lung biopsy, restrictive or mixed ventilation disorders with reduction of diffusing capacity and lung compliance. The results of specific ring precipitation test and counter immunoelectrophoresis were helpful in diagnosis. The importance of early diagnosis and treatment is also discussed.

Adult↗
PubMed1989

[Fluidity of erythrocyte membranes in patients with ischemic cerebral vascular disease].

Measurement of fluidity of erythrocyte membrane (FEM) in thirty-six patients with ischemic cerebral vascular disease (ICVD) by fluorescence polarization of DPH (1,6,-Diphenyl-1,3,5-hexatriene) labelled on lipo-region in intact erythrocyte membrane. Twenty one healthy subjects without any stagnation of blood as control. Also research on coefficient of multiple correlation among the FEM and other factors in whole blood or plasma by using stepwise multi-regression analysis. The results revealed that: (1) FEM of patients with ICVD was 3.55 +/- 0.21 (eta), which was significantly higher than that of healthy subjects (2.77 +/- 0.12 eta), P less than 0.001. (2) The FEM of patients with ICVD were positive correlation with RBC electrophoresis rate, whole blood viscosity and low density lipo-proteins and were negative correlation with high density lipo-proteins. These findings suggested that it would be available for preventing ICVD by increasing of the surface charge on erythrocyte and of the high density lipo-proteins.

Aged↗
PubMed1989

[An electric T test topographic map study of the brain in uremia].

This paper reports the results of statistical mapping on cerebral electric power abnormal distributions in 35 cases of uremia, using cerebral electrical T test topographical map method. The results indicated that the abnormal wide distribution of cerebro-electric activity of uremia was significant (P less than 0.01). The power density of slow wave markedly increased in the right parietal region. The power density of alpha wave obviously decreased in the right parietal side. This study clearly showed that the brain lesions have both the generality of diffuse damage and the particularity of focal damage. A region was seriously invaded by the lesion. The brain lesions have metabolic and toxic encephalopathic features.

Adult↗
PubMed1988

Technetium-99m methoxyisobutyl isonitrile (RP30) for quantification of myocardial ischemia and reperfusion in dogs.

This study was done to determine whether [99mTc]methoxyisobutyl isonitrile (RP30), a nonredistributing myocardial perfusion agent, could be used to quantify regional myocardial blood flow distribution during ischemia and reperfusion, employing sequential injections of tracer, tomographic imaging, and appropriate image subtraction. Dogs underwent transient (6 min) coronary artery occlusion, followed by two paired injections of RP30 and radioactive microspheres combined with tomographic imaging, the first during coronary occlusion and the second after 60 min of reperfusion. To obtain a true image representative of reperfusion, the first set of images was corrected for 99mTc decay and subtracted from the second. During occlusion, tissue microsphere content and scintigraphic RP30 activity in the center of the ischemic region (both expressed as a fraction of the nonischemic region) were closely correlated, although RP30 consistently exceeded microsphere content (0.43 +/- 0.03 vs. 0.24 +/- 0.04, p less than 0.01). Direct tissue counting of RP30 confirmed its relative excess in ischemic myocardium. Reperfusion was successful in 7/8 dogs, with an increase in RP30 activity to 0.98 +/- 0.04 compared to 0.89 +/- 0.03 for microspheres (p = N.S.). In one dog with microsphere-documented persistent ischemia, the RP30 defect was still present after reflow. Our results indicate that because of the lack of myocardial clearance and redistribution, repeat injections of RP30 can be used to quantify serial changes in regional myocardial blood flow.

Animals↗