Biomedical subjects

Y X Liu

Publications and source records attributed to Y X Liu.

At least 19 recordsLinked to original sources

PubMed2006

Neuroprotective role of Z-ligustilide against forebrain ischemic injury in ICR mice.

Radix Angelica sinensis, known as Danggui in Chinese, has been used to treat cardiovascular and cerebrovascular diseases in Traditional Chinese Medicine for a long time. Modern phytochemical studies showed that Z-ligustilide (LIG) is the main lipophilic component of Danggui. In this study, we examined whether LIG could protect ischemia/reperfusion-induced brain injury by minimizing oxidative stress and anti-apoptosis. Transient forebrain cerebral ischemia (FCI) was induced by the bilateral common carotid arteries occlusion for 30 min. LIG was intraperitoneally injected to ICR mice at the beginning of reperfusion. As determined via 2,3,5-triphenyl tetrazolium chloride (TTC) staining at 24 h following ischemia, the infarction volume in the FCI mice treated without LIG (22.1 +/- 2.6%) was significantly higher than that in the FCI mice treated with 5 mg/kg (11.8 +/- 5.2%) and 20 mg/kg (2.60 +/- 1.5%) LIG (P < 0.05 or P < 0.01). LIG treatment significantly decreased the level of malondialdehyde (MDA) and increased the activities of the antioxidant enzyme glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) in the ischemic brain tissues (P < 0.05 or P < 0.01 vs. FCI group). In addition, LIG provided a great increase in Bcl-2 expression as well as a significant decrease in Bax and caspase-3 immunoreactivities in the ischemic cortex. The findings demonstrated that LIG could significantly protect the brain from damage induced by transient forebrain cerebral ischemia. The antioxidant and anti-apoptotic properties of LIG may contribute to the neuroprotective potential of LIG in cerebral ischemic damage.

4-Butyrolactone↗

PubMed2006

Structural, optical, and magnetic properties of Mn-doped ZnO thin film.

The Zn(1-x)Mn(x)O (x = 0, 0.16, and 0.25) thin films were grown on fused quartz substrates by reactive magnetron cosputtering. X-ray-diffraction measurement revealed that all the films were single phase and had wurtzite structure with c-axis orientation. As Mn concentration increased in the Zn(1-x)Mn(x)O films, the c-axis lattice constant and band-gap energy increased gradually. In Raman-scattering studies, an additional Mn-related vibration mode appeared at 520 cm(-1). E(2H) phonon line of Zn(1-x)Mn(x)O alloy was broadened asymmetrically and redshifted as a result of microscopic structural disorder induced by Mn(2+) random substitution. The Zn(0.84)Mn(0.16)O film exhibited a ferromagnetic characteristic with a Curie temperature of approximately 62 K. However, with increasing Mn concentration to 25 at. %, ferromagnetism disappeared due to the enhanced antiferromagnetic superexchange interactions between neighboring Mn(2+) ions.

Journal Article↗

PubMed2006

Herbal medicines for treatment of irritable bowel syndrome.

BACKGROUND: Traditional herbal therapies have been used for a long time to treat gastrointestinal disorders including irritable bowel syndrome, and their effectiveness from clinical research evidence needs to be systematically reviewed. OBJECTIVES: To assess the effectiveness and safety of herbal medicines in patients with irritable bowel syndrome. SEARCH STRATEGY: We searched the following electronic databases till July 2004: The Cochrane Library (CENTRAL), MEDLINE, EMBASE, AMED, LILACS, the Chinese Biomedical Database, combined with hand searches of Chinese journals and conference proceedings till end of 2003. No language restriction was used. SELECTION CRITERIA: Randomised controlled trials of herbal medicines compared with no treatment, placebo, pharmacological interventions were included. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two authors. The methodological quality of trials was evaluated using the components of randomisation, allocation concealment, double blinding, and inclusion of randomised participants. MAIN RESULTS: Seventy-five randomised trials, involving 7957 participants with irritable bowel syndrome, met the inclusion criteria. The methodological quality of three double-blind, placebo-controlled trials was high, but the quality of remaining trials was generally low. Seventy-one different herbal medicines were tested in the included trials, in which herbal medicines were compared with placebo or conventional pharmacologic therapy. Herbal medicines were also combined with conventional therapy and compared to conventional therapy alone.Compared with placebo, a Standard Chinese herbal formula, individualised Chinese herbal medicine, STW 5 and STW 5-II, Tibetan herbal medicine Padma Lax, traditional Chinese formula Tongxie Yaofang, and Ayurvedic preparation showed significantly improvement of global symptoms. Compared with conventional therapy in 65 trials testing 51 different herbal medicines, 22 herbal medicines demonstrated a statistically significant benefit for symptom improvement, and 29 herbal medicines were not significantly different than conventional therapy. In nine trials that evaluated herbal medicine combined with conventional therapy, six tested herbal preparations showed additional benefit from the combination therapy compared with conventional monotherapy. No serious adverse events from the herbal medicines were reported. AUTHORS' CONCLUSIONS: Some herbal medicines may improve the symptoms of irritable bowel syndrome. However, positive findings from less rigorous trials should be interpreted with caution due to inadequate methodology, small sample sizes, and lack of confirming data. Some herbal medicines deserve further examination in high-quality trials.

Drugs, Chinese Herbal↗

PubMed2006

Three-dimensional reconstruction of registered and fused Chinese Visible Human and patient MRI images.

Radiological images are commonly used as important tools in medical diagnoses and treatment. Different modalities of medical images provide uniquely different content. Hence, it is natural and desirable to combine different image modalities to obtain additional new information to enhance clinical assessment. However, given the current technology, radiological images are not always sufficiently informative to permit diagnosis and treatment. In order to address this problem, we fused selected portions of the Chinese Visible Human (CVH) dataset with MRI images from a patient. Specifically, we segmented the caudate nucleus, the lentiform nucleus, and the thalamus in the CVH dataset and then registered and fused this dataset with corresponding MRI images using both rigid and nonrigid registration techniques. After rigid and nonrigid registration, the CVH and MRI images largely coincided with each other. The shape, relationship, and position of focal areas and neural structures were clearly displayed. Using volume and surface rendering, these images were three-dimensionally reconstructed to display the neural structures of interest within the brain. These structures can be rotated at will and observed from different angles. Our research indicates that the fusion of CVH and patients' MRI images can enhance the amount of neural information available to physicians and lay a foundation for the clinical use of the CVH dataset.

Asian People↗

PubMed2006

Short communication: Optimal random regression models for milk production in dairy cattle.

Legendre polynomials of orders 3 to 8 in random regression models (RRM) for first-lactation milk production in Canadian Holsteins were compared statistically to determine the best model. Twenty-six RRM were compared using LP of order 5 for the phenotypic age-season groupings. Variance components of RRM were estimated using Bayesian estimation via Gibbs sampling. Several statistical criteria for model comparison were used including the total residual variance, the log likelihood function, Akaike's information criterion, the Bayesian information criterion, Bayes factors, an information-theoretic measure of model complexity, and the percentage relative reduction in complexity. The residual variance always picks the model with the most parameters. The log likelihood and information-theoretic measure picked the model with order 5 for additive genetic effects and order 7 for permanent environmental effects. The currently used model in Canada (order 5 for both additive and permanent environmental effects) was not the best for any single criterion, but was optimal when considering all criteria.

Animals↗

PubMed2004

Antibacterial and xanthine oxidase inhibitory cerebrosides from Fusarium sp. IFB-121, an endophytic fungus in Quercus variabilis.

Two antibacterial and xanthine oxidase inhibitory cerebrosides, one of which is chemically new, were characterized from the chloroform-methanol (1:1) extract of Fusarium sp. IFB-121, an endophytic fungus in Quercus variabilis. By means of chemical and spectral methods [IR, electrospray ionization MS (ESI-MS), tandem ESI-MS, 1H and 13C NMR, distortionless enhancement by polarization transfer, COSY, heteronuclear multiple-quantum coherence, heteronuclear multiple-bond correlation, and 2-D nuclear Overhauser effect correlation spectroscopy], the structure of the new metabolite named fusaruside was established as (2S,2'R,3R,3'E,4E,8E,10E)-1-O-beta-D-glucopyranosyl-2-N-(2'-hydroxy-3'-octadecenoyl)-3-hydroxy-9-methyl-4,8,10-sphingatrienine, and the structure of the other was identified as (2S,2'R,3R,3'E,4E,8E)-1-O-beta-D-glucopyranosyl-2-N-(2'-hydroxy-3'-octadecenoyl)-3-hydroxy-9-methyl-4,8-sphingadienine. Both new and known cerebrosides, although inactive to Trichophyton rubrum and Candida albicans, showed strong antibacterial activities against Bacillus subtilis, Escherichia coli, and Pseudomonas fluorescens, with their minimum inhibitory concentrations being 3.9, 3.9, and 1.9 microg/mL, and 7.8, 3.9, and 7.8 microg/mL, respectively. Furthermore, both metabolites were inhibitory to xanthine oxidase, with the IC50 value of fusaruside being 43.8 +/- 3.6 microM and the known cerebroside being 55.5 +/- 1.8 microM.

Anti-Bacterial Agents↗

PubMed2003

Establishment of a T-Ag and NF-kappaB binding elements gene co-transfected stable HUVECs cell line.

To set up a T-Ag gene transfected stable human umbilical venous endothelial cells (HUVECs) cell line and a T-Ag, nuclear transcriptional factor kappa B (NF-kappaB) binding elements linked with luciferase reporter gene co-transfected stable HUVECs cell line. Cultured HUVECs were transfected with pCI-neo-T-Ag and pRSV-luc-3XkappaB by lipofectin. The G418 selected monoclones were subcultured. The expression of marker protein, vWF and the characteristic of uptake of lipids were compared by Western blotting and immunocytochemistry in non-transfected and transfected HUVECs. The reporter gene assay was done in the presence of TNF-alpha. A T-Ag gene transfected stable HUVECs cell line and a T-Ag and NF-kappaB binding elements linked with luciferase reporter gene co-transfected stable HUVECs cell lines were set up. The expression of vWF of these cell lines was similar with those in non-transformed HUVECs. The function of uptaking of lipids was preserved as well in transfected cell lines. Furthermore, TNF-alpha, a typical cytokine increasing the activity of NF-kappaB was used to treat the transfected cells O/N. The higher luciferase reporter gene activity was seen. A pCI-neo-T-Ag and pRSV-luc-3X kappaB co-transfected stable HUVECs cell line might be used to check reporter gene activity directly. It might be a useful tool to screen drugs acting on transcription level.

Antigens, Viral, Tumor↗

PubMed2001

Loss of expression of alpha4beta7 integrin and L-selectin is associated with high-grade progression of low-grade MALT lymphoma.

Expression of adhesion molecule in low-grade B-cell mucosa-associated lymphoid tissue (MALT) lymphoma of the gastrointestinal tract has been reported in recent years, but these reports have primarily focused on low-grade gastrointestinal MALT lymphoma. In this study, we examined the lymphocytic homing receptor alpha4beta7 integrin, L-selectin, and VLA-4 and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in low-grade lymphoma of the gastrointestinal tract and other organs such as the ocular adnexa and thyroid. We also observed changes in the expression pattern associated with high-grade transformation. Neoplastic cells in the gastrointestinal low-grade lymphoma and the low-grade component of high-grade MALT lymphoma were found to be alpha4beta7 integrin(+), L-selectin(+), whereas the gastrointestinal high-grade component and diffuse large B-cell lymphoma were found to be alpha4beta7 integrin(-), L-selectin(-). High endothelial venules in the gastric MALT lymphomas expressed MAdCAM-1. In the ocular adnexa low-grade MALT lymphoma, most cases were alpha4beta7 integrin(-), L-selectin(+); and in the thyroid, most cases of both low- and high-grade MALT lymphoma were alpha4beta7 integrin(-), L-selectin(-). These findings show that alpha4beta7 integrin and L-selectin may play an important role in the lymphocyte homing of gastrointestinal low-grade MALT lymphoma and in the loss of alpha4beta7 integrin expression throughout the course of high-grade progression.

Cell Adhesion Molecules↗

PubMed2001

Expression of matrix metalloproteinase-2, tissue inhibitors of metalloproteinase-1, -3 at the implantation site of rhesus monkey during the early stage of pregnancy.

We have examined the expression of MMP-2, TIMP-1, and TIMP-3 mRNA at the implantation site of rhesus monkeys during early stage of pregnancy using in situ hybridization and Northern blot analysis. The results indicate that MMP-2 mRNA was mainly localized in the chorinoic villi and epithelial plaque, suggesting that MMP-2 may be involved in the process of epithelial plaque and trophoblast invasion. TIMP-3 was specifically expressed in the cells around the spiral arteries and maternal-fetal interface. Therefore, TIMP-3 may be the main inhibitor that restricts the trophoblast invasion. The TIMP-1 mRNA was detected in trophoblast villi and maternal decidua; however, its distribution was not cell-specific, suggesting a general role in the protection of trophoblast villi and maternal decidua from proteolysis by the MMPs secreted by themselves.

Animals↗

PubMed2001

Expression of Hsp70-2 in unilateral cryptorchid testis of rhesus monkey during germ cell apoptosis.

We investigated the possible role of Hsp70-2 in germ cell apoptosis induced by heat stress in monkey unilateral cryptorchid testis. The study focused on in situ analysis of the testicular cell DNA fragmentation and on the possible relationship between Hsp70-2 expression and germ cell apoptosis. The TUNEL result showed that most of the germ cells were labeled in the cryptorchid testis on d 5 after induction of cryptorchidism; that with most of the apoptotic germ cells depleted, only a few germ cells were labeled on d 10; and that almost no apoptotic signal was observed in the cryptorchid testis on d 15 and thereafter. This indicates that the increasing germ cell degeneration in cryptorchid testis may take the form of apoptosis. Using in situ hybridization, immunohistochemistry, and Northern blot, we examined the changes of Hsp70-2 expression in the monkey cryptorchid testis. The level of Hsp70-2 mRNA decreased slightly, while the expression of HSP70-2 protein was almost unchanged at the early stage of germ cell apoptosis in the cryptorchid testis on d 5 and dropped dramatically along with the loss of apoptotic germ cells in the cryptorchid testis on d 10 after operation. It is therefore suggested that Hsp70-2 might not take part in inhibiting the apoptosis of germ cells at the early stage during operation-induced cryptorchid testis, and that Hsp70-2 gene does not belong to the immediate early related gene responsible for germ cell apoptosis induced by heat stress.

Animals↗

PubMed2001

[Source of plasminogen activator in rhesus monkey semen and its possible role in sperm capacitation].

Previous studies have demonstrated that plasminogen activator (PA) activity is significantly high in semen of infertile men, which is also high in semen when azoospermia or oligozoospermia is induced by injection of testosterone enanthate (TE) into healthy adult men or rhesus monkeys. To further clarify the source and possible role of PA in semen, the present study was undertaken to examine: (1) whether the mRNAs for tissue type PA (tPA), urokinase type PA (uPA), and PA inhibitor-1 (PAI-1) are expressed in epididymis, seminal vesicle and prostate gland of rhesus monkeys; and (2) whether PA has some effect on in vitro sperm capacitation as judged by the potential of sperm motility, acrosome reaction (AR) and in vitro fertilization. Our results showed that (1) mRNAs for PA and PAI-1 were expressed in epididymis, seminal vesicle and prostate gland, and (2) uPA, but not tPA, improved sperm mobility, induced AR and enhanced sperm capacity to fertilize mature eggs. Thus, it is concluded that PA activity in semen comes not only from testis and epididymis, but also from seminal vesicle and prostate gland; and that uPA, but not tPA, may play a role in sperm capacitation.

Animals↗

PubMed2001

Environmental change in Bashang region historical periods.

The Bashang region is a typical vulnerable eco-environmental zone. Our analysis of paleodunes, paleosol profiles, and lake changes taking place during last ten thousands years indicated that: (1) 10-6.9 ka B.P. was a post-glacial temperature-increasing stage, in which lakes had their high water level; (2) 6.9-3.0 ka B. P. was a large warm stage, during which four paleosol layers were developed and climate fluctuation has assumed 4-5 small cold-humid and cold-dry alternations. Since 5.4 ka B.P., the lakes tended to gradually shrink; and by 2.1 ka B.P., water level has fallen by 2.7 m; (3) since 3.0 ka B. P. a general trend of the region was to change into a dry, warm-dry and cold-dry environment.

Agriculture↗

PubMed2001

Mifepristone regulates expression of apoptosis related genes Fas and FasL in mouse endometrium.

AIM: To investigate the anti-implantation mechanism of mifepriston. METHODS: In situ hybridization and immunohistochemistry were applied to determine mRNA and protein. RESULTS: After mifepriston injection, the number of implantation sites were obviously reduced, mifepriston could inhibit the embryo implantation in mouse. The expression of apoptosis related genes, Fas and FasL, in mouse endometrium was also decreased after mifepriston treatment. CONCLUSION: The expression of apoptosis related genes Fas and FasL is regulated by mifepriston and the inhibitory effect of mifepriston on the embryo implantation may be mediated by action on the Fas/FasL system.

Abortifacient Agents, Steroidal↗

PubMed2001

Role of Fas/FasL genes in azoospermia or oligozoospermia induced by testosterone undecanoate in rhesus monkey.

AIM: To investigate role of apoptosis related genes Fas/FasL in azoospermia or oligozoospermia induced by testosterone undecanoate. METHODS: TUNEL was used to detect the apoptotic signal of testicular cells. Immunohistochemistry and Western blot were used to quantitatively or qualitatively analyze the expression of these apoptosis-related proteins. RESULTS: After injection of testosterone undecanoate, both the apoptotic signal in germ cells and the expression of Fas/FasL in testis increased correlatively in a time-dependent manner, reaching a maximum level on day 30. CONCLUSION: Fas system may initiate and regulate the germ cell apoptosis induced by testosterone undecanoate.

Animals↗

PubMed2001

[Apoptosis during placentation].

Apoptosis is a normal physiological phenomenon. During the process of implantation, there are a large number of cells at the implantation site undergoing apoptosis, which has been suggested to play an important role in the regulation of endometrium decidulization and trophoblast invasion. Apoptosis mediated by Fas/FasL system may also be associated with maternal immunotolerance to the fetus. In this review, the common pathway of apoptosis and the regulation in the placenta are described.

Apoptosis↗

PubMed2001

[Relationship between alpha-ENaC gene Thr663Ala polymorphism and ischemic stroke].

OBJECTIVE: To determine the relationship between Thr663Ala polymorphism in amiloride-sensitive epithelial sodium channel alpha-subunit (alpha-ENaC) gene and ischemic stroke in Chinese population. METHODS: Two hundred and ninety-four patients with cerebral infarction and 280 controls without stroke were screened by polymerase chain reaction (PCR) and corresponding Thr663Ala polymorphism probe hybridization. RESULTS: Thr663Ala polymorphism was in agreement with Hardy-Weinberg equilibrium. Both the carriers proportion (70.75%) and the frequency (48.64%) of 663Ala allele in patients were more prevalent than that in controls (62.86% and 40.89%) (P < 0.05). The presence of at least one 663Ala allele conferred an odds ratio for stroke of 1.429 (95%CI: 1.009-2.025), and the proportion of attributable risk of population (PAR%) was 11.63%. CONCLUSION: Thr 663Ala polymorphism of alpha-ENaC gene may be a genetic risk of ischemic stroke in Chinese population.

Aged↗

PubMed2000

New reference for the age at childhood onset of growth and secular trend in the timing of puberty in Swedish.

UNLABELLED: The objectives of the present work were to present a new reference for the age at childhood onset of growth and to investigate the secular trend in the timing of puberty in a community-based normal population in Sweden. A total of 2,432 children with longitudinal length/height data from birth to adulthood were used to determine the two measures by visual inspection of the measured attained length/height and the change in growth velocity displayed on a computer-generated infancy-childhood-puberty (ICP) based growth chart. The series represents a sample of normal full-term children born around 1974 in Göteborg, Sweden. We found about 10% of children were delayed (>12 mo of age) in the childhood onset of growth based on the previous reported normal range, i.e. 14% in boys and 8% in girls. Distribution of the age at childhood onset of growth was skewed. The medians were 10 and 9 mo for boys and girls, respectively. After natural logarithmic transformation, the mean and standard deviation (SD) were 2.29 (anti-log 9.9 mo) and 0.226 for boys, 2.23 (anti-log 9.3 mo) and 0.220 for girls, respectively. The 95% normal ranges were 6.3-15.4 and 6.0-14.3 for boys and girls, respectively. The distribution of the timing of PHV was close to the normal distribution. The mean values were 13.5 y for boys and 11.6 y for girls with 1 y SD for both sexes. CONCLUSION: A downward secular trend in the onset of puberty was clearly shown in the population. The age at childhood onset of growth did not correlate with the timing of puberty (r = -0.01 and 0.05, p > 0.7 and 0.1 in boys and girls, respectively). Normal ranges of the age at childhood onset of growth are in need of revise, as this study indicates. The new reference presented here could be a reliable indicator in further studies.

Adolescent↗

PubMed2000

[Germ cell apoptosis and regulation in testis].

Both spontaneous and induced germ cell apoptosis occur during the process of germ cell differentiation in testis, which is an important mechanism to remove surplus and abnormal germ cells. It has been known that germ cell apoptosis is under the control of endocrine, cell social association and gene. To elucidate the molecular mechanisms by which germ cell apoptosis is regulated and the elements of the death machinery will provide a basis for effective management of male infertility as well as more targeted approaches to male contraception.

Animals↗