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Biomedical subjects

Y Liu

Publications and source records attributed to Y Liu.

At least 613 records · Page 34Linked to original sources
PubMed2001

[Analysis of apoA IV gene VNTR polymorphism in Chinese endogenous hypertriglyceridemics].

OBJECTIVE: To search the variation of apoA IV gene and its relation to endogenous hypertriglyceridemia (HTG) in Chinese population. METHODS: Forty- seven endogenous hypertriglyceridemics and 48 healthy subjects from a population of Chinese Han nationality in Chengdu area were studied using sequencing of apoA IV gene amplified by polymerase chain reaction (PCR). RESULTS: The frequency of (CTGT)(3) allele in Chinese control group was significantly different from that reported in German Caucasians (0.253 vs 0.607, P<0.01) and in Italian Caucasians (0.253 vs 0.522, P<0.01), but not different from that reported in Japanese (0.253 vs 0.262, P>0.05). The frequency of (CTGT)(3) allele showed no significant difference between normal control and HTG groups(0.223 vs 0.281,P>0.05). In the healthy control group, the subjects with genotype 3/3 of VNTR site had a higher serum mean concentration of LDLC as compared to those with genotype 3/4 (3.698 +/- 0.67 mmol/L vs 2.974 +/- 0.54 mmol/L, P<0.05). CONCLUSION: The results suggest that VNTR polymorphism in apoA IV gene is associated with healthy control subjects to some extent in Chinese population.

Adult↗
PubMed2001

Coordinate regulation of xenobiotic and bile acid homeostasis by pregnane X receptor.

Identification and characterization of the pregnane X receptor (PXR) as a key regulator of cytochrome P450 3A (CYP3A) gene expression has led to an increased understanding of the molecular basis of many drug-drug interactions. Mice lacking PXR (PXR-KO) were used in the present study to delineate the role of PXR in regulating hepatomegaly and regulating the activity of CYP3A, organic anion transporting polypeptide-2 (Oatp2), and Cyp7a1 (cholesterol 7alpha-hydroxylase) gene products in vivo. Pregnenolone-16alpha-carbonitrile (PCN) produced hepatomegaly in the wild-type mice but not in the PXR-KO mice. PCN increased both the number of proliferating cell nuclear antigen immuno-positive nuclei and apparent cell size in the wild-type mice but not in the PXR-KO mice. To determine the role PXR plays in regulating CYP3A activity, 6beta-hydroxylation of testosterone and the duration of the loss of righting reflex following administration of the muscle-relaxant zoxazolamine were measured. PCN increased the level of testosterone 6beta-hydroxylation and decreased the duration of the loss of righting-reflex time following zoxazolamine administration in wild-type mice, but did not effect either of these parameters in PXR-KO mice. PCN increased the hepatic uptake of [(3)H]digoxin, an Oatp2 substrate, in wild-type mice but not in the PXR-KO mice. Similarly, PCN decreased bile acid excretion in wild-type mice but not in the PXR-KO mice. Taken together, these data demonstrate a pivotal role for PXR in the regulation of drug-induced hepatomegaly and in the metabolism (CYP3A), transport (Oatp2), biosynthesis (Cyp7a1), and excretion of xenobiotics and bile acids in vivo.

Animals↗
PubMed2001

Is tumor expression of the major histocompatibility complex antigen required for T cell immune surveillance?

Tumor expression of major histocompatibility complex antigen (MHC) class I and class II is not essential for the induction of memory T cells. However, induction of MHC class I-restricted effector cytotoxic T cells (CTL) appears dependent on MHC class I expression on tumors. Moreover, the effector function of tumor-specific CTL requires direct recognition of the tumor. In contrast, both the inductive and the effector phases of MHC class II-restricted T cells are independent of MHC class II expression on tumors.

Histocompatibility Antigens Class I↗
PubMed2001

[Protective effect of tanshinone IIA on acute hepatic injury in mice].

OBJECTIVE: To study the effect of tanshinone IIA on two models of acute hepatic injury in mice. METHODS: Two acute hepatic injury models induced by carbon tetrachloride (CCl4) and D-galactosamine (D-GalN) in mice were used. ALT, AST in serum and MDA in liver homogenate were used as indexes. RESULTS: Tanshinone IIA (10 mg.kg-1, 20 mg.kg-1, 30 mg.kg-1), similar to biophenyldicarboxylate, could decrease ALT, AST in serum and MDA in hepatic homogenate on acute hepatic injury induced by CCl4 and D-GalN. CONCLUSION: Tanshinone IIA possessed obvious protective effect against liver injury induced by CCl4 or D-GalN.

Abietanes↗
PubMed2001

Experiences from a collaborative project on the prevention of disability in leprosy patients in Shandong Province, the People's Republic of China.

Shandong Province (present population 89 million) in the People's Republic of China established a leprosy control programme in 1955. Between that year and the end of 1999, allowing for death and migration, the cumulative number of cases registered was 53,618, including 120 cases on multiple drug therapy (MDT) and 18,248 who had completed satisfactory courses of dapsone monotherapy and/or MDT. Of this latter group, 9500 cases (52%) suffered from visible disabilities (grade 2 of the WHO classification). Prevalence and incidence rates of leprosy have decreased dramatically since 1955 and, on average, only 50-70 new cases are now being detected annually in the entire province. Leprosy is thus no longer a public health problem, but the existence of such a large number of patients with grade 2 disabilities is clearly a matter of serious concern. This paper describes a pilot project to investigate the potential of health personnel in the leprosy programme and the dermatology and sexually transmitted diseases services to (a) prevent deterioration of existing disabilities in ex-patients through self-care and (b) prevent new neuritis in patients on MDT through early detection and the use of steroids.

Adult↗
PubMed2001

A retrospective study of continuous renal replacement therapy versus intermittent hemodialysis in severe acute renal failure.

OBJECTIVE: To investigate the efficacy of continuous renal replacement therapy (CRRT) versus intermittent hemodialysis (IHD) in patients with severe acute renal failure (ARF). METHODS: One hundred and ninety-three severe ARF patients who received renal support between December 1978 and December 1998 were involved in this study. Of them, 101 (52.3%) were treated with CRRT (CRRT group), and 92 (47.7%) with IHD (IHD group). RESULTS: Sixty (59.4%) patients in the CRRT group got through the acute phase of disease and 41 (40.6%) patients did not survive while in the IHD group 59 (64.1%) patients survived and 33 (35.9%) patients did not. No significant difference in survival rate was found between the two groups. 24 of 64 patients (37.5%) in the CRRT group with multiple organ dysfunction syndrome (MODS) survived, while in the IHD group, 8 out of 44 (27.3%) survived, their survival rate was much lower than that in the CRRT group. Patients in CRRT group were more severely ill, as manifested by lower mean arterial pressure, higher APACHE II score, more dysfunctioned organs and requiring mechanical ventilation and vasopressor support as compared with patients in the IHD group, CRRT was found to improve hemodynamic stability with a better fluid balance and control of biochemical status, increased nutritional intake and a shorter duration of acute renal failure (P < 0.05). CONCLUSION: CRRT perhaps may be the best choice in the treatment of severe ARF patients, for it can offer several distinct advantages compared to IHD. These may contribute to improving the survival rate of ARF patients, particularly those that are critically ill patients.

Acute Kidney Injury↗
PubMed2001

The matrix metalloproteinase gene GmMMP2 is activated in response to pathogenic infections in soybean.

Matrix metalloproteinases (MMPs) play an important role in host defense responses against pathogens in mammals where their activities lead to the production of antimicrobial peptides. We have identified a novel soybean (Glycine max) metalloproteinase gene, GmMMP2, that is transcriptionally up-regulated in infected tissues. The deduced amino acid sequence indicates that this gene belongs to the MMP family. It is a preproprotein containing an N-terminal signal peptide, a cysteine switch, a zinc-binding catalytic motif, and a C-terminal transmembrane domain. The GmMMP2 expressed in and purified from Escherichia coli exhibited an in vitro enzymatic activity in digesting myelin basic protein. All plant metalloproteinases reported so far have no known functions. However, they have been suggested to be involved in extracellular cell matrix degradation during development or senescence. Our investigations demonstrate that the GmMMP2 transcript levels were rapidly increased in compatible and incompatible interactions of soybean tissues with the oomycete pathogen Phytophthora sojae or the bacterial pathogen Pseudomonas syringae pv. glycinea. In agreement with the GmMMP2 activation, a metalloproteinase activity was gradually increased in suspension-cultured cells following the bacterial infection. GmMMP2 was also activated in response to wounding and dehydration. However, GmMMP2 activation did not correlate with the oxidative burst leading to the hypersensitive response cell death or the tissue senescence progress that involves programmed cell death. Our investigations suggest that GmMMP2 may be involved in a novel defense response of soybean against pathogenic infections.

Amino Acid Sequence↗
PubMed2001

[Characteristic analysis on different thermal active surfaces in canopy gap of tropical secondary forest].

Microclimatic measurements were conducted in the canopy gap of tropical secondary forest in Xishuangbanna in fog-cool and dry-hot season. The daytime thermal effect of different thermal active surface in the canopy gap was discussed, and the variations of trunk surface temperature near gap edge and of surface temperature on the gap were analyzed. The result shows that the woody-wall surface is new thermal active surface on the vicinage of canopy gap, with the exception of the forest canopy surface, soil surface in the forest gap, and soil surface of the interior. Because of the influence of season, situs and time, the thermal effect of different thermal active surface of gap was significant different. Being subject to fog, the soil surface on the center of canopy gap is an important thermal active surface in the morning; while in the midday and afternoon, because of the influence of incident radiation, the woody wall and soil surface of edge on the east and the woody wall surface of edge on the north are the key thermal active surface of the canopy gap. In the midday, the thermal active was salient on the surface of gap, and in the afternoon, it was salient on the woody wall. The thermal variations of canopy gap of forest are controlled by the thermal characteristics of different thermal active surfaces and by their interaction, affecting the growth of plants.

Temperature↗
PubMed2001

[Effect of natural zeolite on nutrient preserving capability of degraded slope soil in south China].

Soil column leaching experiment showed that after zeolite application, the content of nitrogen and potassium in leachate was reduced significantly, but no significant effect was detected for phosphate. This application had a positive effect on soil available nitrogen, phosphorus and potassium. It increased the content of soil AL-P and Fe-P, but did not increase the NO3-N content in leachate.

Fertilizers↗
PubMed2001

[Effect of different tillage methods on rice growth and soil ecology].

Field experiments were conducted in double-cropping rice field in South China during 1998-1999 to study the effect of different tillage methods on rice growth and soil ecology. The results showed that with rice scattering planting, no-tillage method caused a reduction of rice tillering, effective panicle, and filled grains of rice. Grain yield under no-tillage was 13.40% lower than that under conventional tillage, and the economic benefits decreased by 10.9%. Soil analysis showed that in no-tillage fields, soil bulk density and hardness were increased, soil porosity and available P and K were decreased, the amount of actinomyces and fungi was reduced, while that of soil bacteria was increased, and the enzyme activity was promoted. Minimum tillage and conventional tillage had similar soil physical and chemical properties, soil microbial quantity and enzyme activity. Minimum tillage could produce a 2.1% higher grain yield than conventional tillage, and increase the economic benefits by 11.0%.

Agriculture↗
PubMed2001

[Effects of volatiles from different trophic level on foraging behavior of Aphidius avenae].

The responses of female Aphidius avenae to volatiles from undamaged wheat plant, Sitobion avenae and Rhopalosiphum padi, aphids-plant complexes and aphids damaged plant were investigated in wind tunnel and Y-tube olfactometer. The volatiles from undamaged wheat plant, S. avenae and R. padi were much less attractive to A. avenae than those from aphids-plant complexes and aphids-damaged plant. Although the parasitic rate was much lower, the R. padi-plant complexes and R. padi damaged plant were also attractive to A. avenae. Identification of volatiles by GC-MS showed that the main volatiles induced by aphids feeding were 2-camphene, 6-methyl-5-hepten-2-one, 6-methyl-5-hepten-2-ol, Z-3-hexenyl-acetate, and methyl salicylate, among which, 6-methyl-5-hepten-2-one and 6-methyl-5-hepten-2-ol were more attractive to A. avenae, while methyl salicylate was not attractive.

Animals↗
PubMed2001

[Experimental study of Bcl-2 and Fas gene expression in fibroblast of scar].

OBJECTIVE: To explore the effect of Fas/Apo-1 and Bcl-2 gene expression on mechanism of scar formation. METHODS: Immunohistochemical method was applied to defect the expression of Fas and Bcl-2 protein in fibroblasts from 10 cases with normal skin, 10 cases with hypertrophic scar and 10 cases with keloid. RESULTS: The positive expression rate of Bcl-2 protein in keloid was 83.2%, significantly higher than that in hypertrophic scar (38.6%), (P < 0.01), and the positive expression rate in hypertrophic scar and keloid was higher than that in normal skin (6.78%), (P < 0.01). But the positive expression rate of Fas/Apo-1 protein was 78.4% in normal skin 80.4% in hypertrophic scar, 84.4% in keloid respectively, which showed no significant difference among them (P > 0.05). CONCLUSION: Bcl-2 gene but Fas gene may take part in the formation of pathologic scar.

Adolescent↗
PubMed2001

[Research on the school of Danxi of the Ming dynasty].

Zhu Danxi, the founder of Danxi School, one of the four major schools of the Jin - Yuan dynasties, was famous for its Yin - nourishing theory. Clinically, it was adept in treating miscellaneous disorders, with the "four - injury theory" as its theory for differentiation of Zheng. The medical thinking of Danxi is quite specific that it exerted its clinical and academic influence mostly in the Ming dynasty, with so many schools followed him. Though research on its origin and evolution, direct followers like Dai Sigong, Wang Lü, Lin Chung et al. not only totally inherited Danxi's medical idea, but also became the receiver of his academic experiences. Indirect followers(study perronally) reached its peak in the Ming dynasty. They inherited Danxi's experience and further developed to supplement his theory. For other physicians partly following Danxi's experience also emerged and applied his academy for further development of medical theory.

China↗
PubMed2001

[The window parascapular free flap for the treatment of severe facial scar contracture].

OBJECTIVE: To present the clinical application of the window parascapular free flap. METHOD: The window parascapular free flap was used in 6 cases of serious facial burn scar contracture. The age of the patients ranged from 5 to 17 years. Based on circumflex scapular vessels, small windows were made on the flap for the palpebral fissure, the oral fissure, the nostrils or the external auditory meatus. The flap size ranged from 15 cm x 8 cm to 17 cm x 17 cm. All the free flaps were successful. RESULTS: With the survival of the free flap, the nose, the lids, the lips, etc. were reconstructed at the same time and obtained good appearance. CONCLUSION: For repair of serious facial burn scar contracture, the window parascapular free flap was successfully used to reconstruct the eye, the mouth, the nose and the ear. The method is safe and reliable because the blood supply of the scapular free flap was not affected by the opening.

Adolescent↗
PubMed2001

[Applied anatomic study of the pudendal-thigh flap and establishment of flap model].

OBJECTIVE: To investigate the anatomic base of the pudendal-thigh flap and establish flap model. METHODS: Skin dissection of pudendal-thigh regions was performed on 10 cadavers (20 sides). All afferent and efferent vessels were measured and recorded. RESULTS: There exist multiple blood supplies of pudendal-thigh flap. Anterior cutaneous branches of obturator artery spread out on middle portion of flap. Piercing site of it is (3.0 +/- 0.5) cm apart from middle line of perineum, (1.7 +/- 0.4) cm from anterior margin of vaginal introitus, (0.6 +/- 0.2) cm from outer fringe of lower pubic rami and (0.8 +/- 0.1) mm in diameter. Posterior labial arteries mainly supply the major labia and constantly anastomose with superficial external pudendal arteries in direct vascular anastomosis in subcutis of major labia. The main stems send out 2-3 lateral branches of posterior labial arteries which distribute to posterior portion of the pudendal-thigh flap. CONCLUSION: The major vessels of pudendal-thigh flaps used to form a neovagina are lateral branches of posterior labial arteries and not the main stem itself. Flaps pedicled on the anterior cutaneous branches of obturator arteries may be elevated to repair rectovaginal fistula or small skin defects of perineum and not suited to reconstruct a neovagina as its piercing point of blood vessels is much higher and the location of pedicle is more fixed.

Female↗
PubMed2001

[An analysis for causes of skeletal relapse after correction of mandibular prognathism by BSSRO].

OBJECTIVE: To investigate the factors responsible for the skeletal relapse after correction of mandibular prognathism by BSSRO. METHODS: The skeletal and dental changes before and after the surgery were analysed by cephalometrics, The factors that might be responsible for the skeletal relapse were evaluated using multiple linear and partial correlation analysis. RESULTS: The changes of NP-FH angle at follow up had a significant correlation with MP-FHT4-3 angle, the duration of presurgical orthodontics and the observation period after surgery(r = -0.568, -0.406, -0.400, P < 0.01-0.05). CONCLUSION: The skeletal relapse following BSSRO was limited. The stability was related to the period of presurgical orthodontics and the mandibular rotation after the surgery.

Female↗
PubMed2001

[Effect on the pregnant woman and fetus by multiple hepatitis virus infection].

OBJECTIVE: To evaluate the effect on the pregnant woman and fetus by infection of multiple hepatitis virus during pregnancy. METHODS: Hepatitis virus A, hepatitis virus B, hepatitis virus C, hepatitis virus D and hepatitis virus E were determined in the pregnant women with abnormal liver function during 1994-1999. Patients diagnosed to be infected by single hepatitis virus or multiple hepatitis virus were divided into two groups and complications of the pregnant woman and fetus and their prognosis were evaluated. RESULTS: There were no significant differences in the levels of alamine transaminase (ALT), aspartama transaminase (AST) and total bilirubin (TBIL) between the multiple hepatitis virus infection group (multiple group) and the single hepatitis virus infection group (single group) (P > 0.05). The positive rate of HbeAg (35.7%) in multiple group was significantly lower than in single group (P < 0.05). However, the positive rate of HbeAb (57.1%) in multiple group was significantly higher than in single group (P < 0.01). There were no significant differences in incidences of pregnancy induced hypertension (PIH), postpartum hemorrhage, serious symptoms and mortality between the multiple hepatitis virus infection group and the single hepatitis virus infection group (P > 0.05). However, the incidences of premature rupture of membrane (PROM), premature delivery, 28.1%, 25.0% fetal distress and newborn infant asphyxia 31.3%, 25.0% in multiple hepatitis virus infection group were significantly higher than in single hepatitis virus infection group (P < 0.05, P < 0.01). CONCLUSIONS: Multiple hepatitis virus infection during pregnancy has no more serious effect on the pregnant woman, but has worse effect on fetus than single hepatitis virus infection. The obstetrician should pay more attention to the health care of the pregnant woman with the multiple hepatitis virus infection to prevent PROM and premature delivery, at the same time monitor fetus carefully and deal with labor actively to decrease the mortality of the fetus.

Adult↗