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Biomedical subjects

Ying Li

Publications and source records attributed to Ying Li.

At least 307 records · Page 17Linked to original sources
PubMed2003

Expression of CycD3 is transiently increased by pollination and N-(2-chloro-4-pyridyl)-N'-phenylurea in ovaries of Lagenaria leucantha.

Lagenaria leucantha is an important vegetable crop and a potential model for the study of fruit development. To study the function of D cyclins in fruit development, full-length cDNA clones for two D cyclin genes were isolated from young ovaries of Lagenaria leucantha. They were classified as D3 cyclins by sequence similarities and phylogenetic analysis, and nominated LlCycD3;1 and LlCycD3;2, respectively. The deduced amino acid sequence of both LlCycD3 genes contained a retinoblastoma-binding motif and a PEST-destruction motif. Unpollinated ovaries failed to develop and eventually aborted. N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU) induced parthenocarpic fruit significantly larger than pollinated ones. In unpollinated ovaries, the expression of both LlCycD3 genes was abundant at anthesis and then suddenly decreased, concomitant with the cessation of cell division. Pollination/fertilization induced an activation of the cell cycle accompanied by a large increase in the transcript levels of LlCycD3;1 and LlCycD3;2 in young fruits. Treating ovaries with CPPU also reactivated cell division and transcription of CycD3 genes and the effect was more rapid and pronounced than after pollination/fertilization.

Amino Acid Sequence↗
PubMed2003

A novel serine protease of the mammalian HtrA family is up-regulated in mouse uterus coinciding with placentation.

This paper characterizes a novel gene, previously identified as uniquely regulated at implantation in mouse uterus. We cloned its full mRNA sequence encoding a serine protease possessing an IGF-binding domain and named it pregnancy-related serine protease (PRSP). PRSP is structurally similar to mammalian HtrA1 (56% amino acid similarity). Northern analysis revealed that the expression of PRSP mRNA was low before pregnancy, but it was increased at implantation and markedly up-regulated post-implantation. In-situ hybridization localized low levels of mRNA expression to the epithelium and stroma during very early pregnancy, but high expression to the decidual cells on day 8.5, primarily at the mesometrial pole where the placenta was forming. By day 10.5, PRSP mRNA was detected in the placenta. We also cloned an alternatively spliced PRSP mRNA that is expressed at a very low level. We located PRSP gene on chromosome 5 and established its intron/exon structure, which unambiguously explains how the two mRNA variants are produced through alternative splicing. Based on PRSP protein domain structure and its unique expression during pregnancy, we propose that PRSP plays an important role in the formation/function of the placenta.

Amino Acid Sequence↗
PubMed2003

Specific and transient up-regulation of proprotein convertase 6 at the site of embryo implantation and identification of a unique transcript in mouse uterus during early pregnancy.

The present investigation was conducted to identify and characterize an mRNA that was found by RNA differential display to be uniquely regulated at the sites of embryo implantation in mouse uterus. This mRNA was upregulated at the sites of blastocyst attachment at implantation and was identified as proprotein convertase 6 (PC6). PC6 mRNA level was low in the nonpregnant and early pregnant uterus before embryo implantation commenced (before Day 4.5, vaginal plug = Day 0). During the initiation and progression of blastocyst attachment (around Day 4.5), the mRNA was dramatically upregulated only at the implantation sites. The increased transcription was maintained on Day 5.5; the mRNA level declined slightly on Day 6.5 and then fell sharply to reach the nonpregnant level around Days 8.5-10.5. Thus, the upregulation is transient and coincides with the period of embryo attachment and implantation; it is also very specific to implantation sites. In situ hybridization analysis localized the mRNA expression predominantly in the decidual cells immediately surrounding the implanting embryo at the antimesometrial pole. Additionally, multiple mRNA species resulting from alternative splicing were observed in the uterus, as previously reported in the intestine and brain, and further analysis of these transcripts identified a uterine-specific PC6 mRNA. These data lead us to suggest that PC6 plays an important role in the processes of stromal cell decidualization and embryo implantation.

Animals↗
PubMed2003

Use of the dnaJ gene for the detection and identification of all Legionella pneumophila serogroups and description of the primers used to detect 16S rDNA gene sequences of major members of the genus Legionella.

We sequenced about 930 bp of the dnaJ gene from 15 Legionella pneumophila serogroups and some other members of the genus Legionella. As L. pneumophila 16S rDNA sequences could not discriminate between all subspecies and serogroups, we assessed the use of dnaJ gene sequences to differentiate between Legionella subspecies as well as between L. pneumophila serogroups. A phylogenetic analysis revealed that dnaJ gene sequences were more variable between the L. pneumophila serogroups than mip gene and 16S rDNA sequences. By studying 61 strains from 41 species of the genus Legionella, as well as other genera, we established a PCR method that could amplify 285 bp of dnaJ gene from all L. pneumophila serogroups. This primer set was more sensitive than mip gene primers and was able to detect 0.25 ng of purified DNA. We also describe the 16S rDNA primers that were used to detect most Legionella genus members.

Bacterial Proteins↗
PubMed2003

Musings on the wanderer: what's new in our understanding of vago-vagal reflexes? V. Remodeling of vagus and enteric neural circuitry after vagal injury.

The vago-vagal reflexes mediate a wide range of digestive functions such as motility, secretion, and feeding behavior. Previous articles in this series have discussed the organization and functions of this important neural pathway. The focus of this review will be on some of the events responsible for the adaptive changes of the vagus and the enteric neutral circuitry that occur after vagal injury. The extraordinary plasticity of the neural systems to regain functions when challenged with neural injury will be discussed. In general, neuropeptides and transmitter-related enzymes in the vagal sensory neurons are downregulated after vagal injury to protect against further injury. Conversely, molecules previously absent or present at low levels begin to appear or are upregulated and are available to participate in the survival-regeneration process. Neurotrophins and other related proteins made at the site of the lesion and then retrogradely transported to the soma may play an important role in the regulation of neuropeptide phenotype expression and axonal growth. Vagal injury also triggers adaptive changes within the enteric nervous system to minimize the loss of gastrointestinal functions resulting from the interruption of the vago-vagal pathways. These may include rearrangement of the enteric neural circuitry, changes in the electrophysiological properties of sensory receptors in the intramural neural networks, an increase in receptor numbers, and changes in the affinity states of receptors on enteric neurons.

Animals↗
PubMed2003

The glial sling is a migratory population of developing neurons.

For two decades the glial sling has been hypothesized to act as a guidance substratum for developing callosal axons. However, neither the cellular nature of the sling nor its guidance properties have ever been clearly identified. Although originally thought to be glioblasts, we show here that the subventricular zone cells forming the sling are in fact neurons. Sling cells label with a number of neuronal markers and display electrophysiological properties characteristic of neurons and not glia. Furthermore, sling cells are continuously generated until early postnatal stages and do not appear to undergo widespread cell death. These data indicate that the sling may be a source of, or migratory pathway for, developing neurons in the rostral forebrain, suggesting additional functions for the sling independent of callosal axon guidance.

Animals↗
PubMed2003

Angiography for diagnosis and treatment of colorectal cancer.

AIM: To evaluate the role of preoperative angiography in the diagnosis and treatment of colorectal cancer. METHODS: The authors performed selective arterial cannulation by Seldinger's method in 47 patients to locate the primary cancer and to diagnose metastasis to the liver. Each patient was then given intra-arterial regional chemotherapy, and received 5-fluorouracil (5-Fu, 1 000 mg), mitomycin C (MMC, 20 mg), and cisplatinum (CDDP, 80 mg). RESULTS: The location and shape of each tumor were observed, including metastatic tumors in the liver, in 42 of the 47 (89.4 %) patients. The site of the primary tumor was difficult to identify in 5 cases because the patients had a recurrence of cancer. Arterial chemotherapy was performed successfully in all patients. The authors recorded no partial or significant morbidity resulted from angiography. The only incident was bleeding from the artery puncture site in one patient, which was successfully stopped by general medication. CONCLUSION: Preoperative selective arterial angiography can help the diagnosis and locate primary tumors and to detect liver metastasis. At the same time, regional arterial chemotherapy can be an important form of preoperative therapy.

Adult↗
PubMed2003

[Analysis on the aetiology of influenza in children in Tianjin].

OBJECTIVE: To analyse the pathogen of child patients with influenza in Tianjin area. METHODS: The influenza virus isolation was performed by MDCK cells and embryonated eggs. The identification of the isolates was carried out with hemagglutination (HA) and hemagglutination inhibition (HI) tests. RESULTS: Two hundred and thirty-eight throat swab specimens from children with influenza-like illness were collected in Tianjin area from Oct. 2001 to Mar. 2002 and 64 strains (26.9%) of influenza virus were isolated. Data showed that there were 42 strains (65.6%) of A (H3N2) subtype, 13 strains (20.3%) of A (H1N1) subtype and 9 strains (14.1%) of B type in these positive isolates. All the isolated viruses grew very well in MDCK cells and hemagglutinated with human "O" red blood cells, and most (62/64 strains) of them were able to multiply in embryonated chick eggs. However, there were only 3 isolates with HA positive in inoculating embryonated eggs with the specimens. Meanwhile, it was revealed that out of 55 strains of A type viruses, 53 strains (96.4%) were from O to D phase, 2 strain of A (H3N2) were D phase characters and all B type isolated viruses being D phase properties. CONCLUSION: There were three endemic types of influenza viruses-A (H3N2), A (H1N1) and B type in Tianjin area, with A, the main type.

Adolescent↗
PubMed2003

[Effects of male reproductive health information education communication on mastering STDs knowledge among young couples].

OBJECTIVES: To increase the knowledge of STDs control and prevention among young couples by intervention, and to improve their reproductive health. METHODS: The intervention plan was made and carried out on the basis of the information from baseline interview and Focus Group Discussions. The activities of the intervention included lectures given by experts, counseling service, delivering knowledge foldouts and knowledge competition. The final survey was conducted. The data of baseline and final survey were analyzed with SAS software. RESULTS: Before intervention, young couples knowledge of STDs was similar between the experimental and the control group. After intervention, proportion of knowing numbers of STDs kinds in experiment group significantly was higher than that in control group(P < 0.01); The proportion of knowing harm of STDs and knowing to use consom to prevent STDs couples were significantly higher in experiment group than that in control group(P < 0.01). CONCLUSIONS: The intervention activities including lectures and counseling services were positive and great sociological affects on family planning and reproductive health improvement for young couples which has one child.

Adolescent↗
PubMed2003

[Study on changing regularity of leptin, estradiol and testosterone during peripuberty in girls].

To study the changing regularity of leptin during puberty in girls and the relationship of leptin, estradiol and testosterone each other, serum levels of leptin, estradiol(E2) and testosterone(T) were determined in blood in 150 obese girls, 150 normal girls and 150 malnourished girls, aged from 7 to 17 years old. Their ages of menarche were surveyed. The results showed that serum levels of leptin increased with age, and had double peaks. The first peak of leptin was found during the early phase of puberty in all groups. The value of peak were 14.46 micrograms/ml, 8.85 micrograms/ml, 8.60 micrograms/ml in obese, normal and malnourished groups respectively. The second peak of leptin emerged at the end of puberty in the three groups. The level of E2 increased sharply at the eleven years old in three groups, then increased progressively with age. Serum level of E2 did not correlated with leptin. There was a peak level of T at 10 years old in obese groups, as well as normal and malnourished groups. The level of T emerged rise sharply at 12 years old after a decrease in all groups. Serum level of T did not correlated with leptin. It is suggested that leptin may be a more important decisive factor during pubertal development course in girls. The first peak of leptin may be the signal of onset of puberty. The second peak of leptin may be the signal of the end of puberty.

Adolescent↗
PubMed2003

[Roles of leptin in the development during girls'puberty].

OBJECTIVES: To study the roles of leptin in the development during puberty in girls and the its relationship with insulin (INS), growth hormone (GH), estradiol (E(2)) and testosterone (T). METHODS: One hundred and fifty girls with simple obese aged 7 to 17 years, and 150 normal healthy girls and 150 girls with malnutrition matched for age (+/- 3 months) and height (+/- 2 cm) were selected. Serum levels of leptin, INS, GH, E(2) and T were measured for them. RESULTS: Their serum level of leptin positively correlated with body mass index (BMI) and age. Serum level of leptin in girls increased steadily from Tanner stage B(1) to stage B(5). At Tanner stage B(2), serum level of leptin in the normal groups (7.72 microg/L) was not significantly different from that in those with malnutrition (7.36 microg/L), but significantly lower than that in the obese groups (12.85 microg/L). At other Tanner stages, there was significant difference in serum level of leptin among obese, normal and malnutrition groups. Serum level of leptin correlated negatively with serum GH and positively with serum INS, but not correlated with E(2) and T. CONCLUSIONS: Leptin may play a role in triggering development during puberty in girls. Serum level of leptin at Tanner stage B(2) may be the threshold dose to trigger the onset of puberty in girls. Quickly increasing level of leptin at Tanner stage B(5) may inhibit the increase of GH, which ushered the end of puberty in girls.

Adolescent↗
PubMed2003

[Expression and significance of the urokinase-type plasminogen activator and its inhibitors in squamous cell carcinoma of human larynx].

OBJECTIVE: To detect the expression of urokinase-type plasminogen activator (uPA) and its inhibitors(plasminogen activator inhibitors, PAI) type-1 and type-2 in squamous cell carcinoma of human larynx and reveal the correlation of the major clinicopathologicl parameters and prognosis. METHODS: uPA, PAI-1 and PAI-2 were detected from 104 cases squamous cell carcinoma of human larynx undergoing primary resection using immunohistochemistry(labeled-streptoavidin-biotin-peroxidase, SAB) method. The results were classified positive and negative. Patients were followed-up prospectively for a median of 41 months(rang 24 to 84 months). Overall survival were analyzed according to Kaplan-Meier and log-rank statistics, the prognostic relevance of uPA, PAI-1 and PAI-2 and conventional prognostic factors were analyzed by Cox analyses. RESULTS: uPA, PAI-1 and PAI-2 positivity were present both in neoplastic cells and in fibroblast cells and macrophages. However, depending on the histological grading and invasive capacity of the tumor, a pronounced intra- and intertumoral heterogeneity in uPA staining was observed. The total positive rate of uPA, PAI-1 and PAI-2 was 66.3%, 70.2% and 50.0% respectively. No relationship between the expression of these proteins and clinicopathological parameters except for lymph node metastasis and recurrence, P value was 0.010, 0.027 and 0.038 respectively. Univariate survival analysis revealed a high significant inverse correlation of uPA positive expression survival time. Patients with PAI-2 positive expression had a significantly longer survival time than those with PAI-2 negative expression. In different clinicopathological parameters subgroups, uPA, PAI-1 and PAI-2 added significant survival information. Multivariate analysis revealed that four independent prognostic factors for overall survival time were uPA, PAI-2, lymph node metastasis and recurrences and clinical stage, P = 0.001, 0.002, 0.035 and 0.005 respectively. CONCLUSION: These findings suggest that uPA play important role in the metastasis of human laryngeal carcinoma and PAI-2 appears to be a true inhibitor contrary to PAI-1. PAI-1 might act as an essential modulator of the plasminogen activation system or a protector of carcinoma tissue against self-degradation rather than as a simple inhibitor of system. uPA and PAI-2 could be new independent and strong biologically prognostic factors.

Adult↗
PubMed2003

[Psychological health status of students taking part in medical support for military training on the sea].

OBJECTIVE: To investigate the adaptability and psychological health status of the students from the military medical universities enrolled in the medical support service for military training on the sea, so as to provide more pertinent and specific psychological advice for students in military medical universities. METHODS: The psychological health status of 139 students were assessed by issuing a self-rating symptom scale (SCL-90) before the training and later before the maneuvers commenced, respectively. RESULTS: Except for obsessive-compulsive and interpersonal sensitivity factors, significant increases were recorded in the scores for other factors immediately before the maneuvers as compared with those recorded before the training (P<0.01, P<0.05). The positive symptom rates of various factors measured before the maneuvers were also higher. CONCLUSIONS: It is the essential task for daily psychological health education to help the students foster psychological self-regulation ability and cope with stresses to strengthen their psychological well-being. Building self-confidence, improving the adaptability and conquering fears should be the primary concern of the psychological advisors before military actions.

Adaptation, Psychological↗
PubMed2003

[Mean level of blood pressure and rate of hypertension among people with different levels of body mass index and waist circumference].

OBJECTIVE: To assess the relationship between body mass index (BMI), waist circumference (WC) and blood pressure (BP) including hypertension. METHODS: A total of 30 003 participants aged 35 - 59 from different parts of China were surveyed for cardiovascular disease risk factors in two independent cross-sectional studies that were carried out in 1992 - 1994 and in 1998. Data were pooled to analyze the levels of BP and rates of hypertension with different levels of BMI and WC. RESULTS: The level of BP and rate of hypertension were significantly increasing with rising of WC among the majority of BMI groups (P value for trend < 0.05) and significantly increasing with rising of BMI in all WC groups (P value for trend < 0.05). The age adjusted hypertension rate with BMI < 24.0 kg/m(2) and WC < 85/80 cm (men/women), BMI < 24.0 kg/m(2) and WC >or= 85/80 cm (M/W), BMI 24.0 - 27.9 kg/m(2) and WC < 85/80 cm (M/W), BMI 24.0 - 27.9 kg/m(2) and WC >or= 85/80 cm (M/W), BMI >or= 28 kg/m(2) and WC >or= 85/80 cm (M/W) were 16.5%, 29.8%, 29.6%, 39.2% and 57.5% for men and 14.1%, 20.6%, 24.7%, 30.3% and 43.3% for women, respectively. CONCLUSION: Independent influence of BMI or WC on BP was noticed. Keeping BMI and WC at normal level might effectively prevent the occurrence of hypertension.

Adult↗
PubMed2003

Role of calcium mobilization in sodium nitroprusside-induced increase of calcium-activated potassium currents in gastric antral circular myocytes of guinea pig.

AIM: To investigate the role of calcium mobilization in the calcium-activated potassium currents [IK(Ca)] increased by sodium nitroprusside (SNP), a nitric oxide (NO) donor, in gastric antral circular myocytes of the guinea pig. METHODS: A perforated patch-clamp technique was used, and the myocytes were isolated by collagenase. RESULTS: SNP 100 mol/L significantly increased IK(Ca), and enhanced the spontaneous transient outward currents (STOC). SNP-induced increase of IK(Ca) was not blocked by extracellular calcium-free solution (containing egtazic acid 10 micromol/L and nicardipine 5 micromol/L, an L-type calcium channel blocker. And SNP 100 micromol/L suppressed the L-type calcium currents (ICa). SNP-induced increase of STOC was inhibited by heparin 3 g/L, a potent inhibitor of inositol triphosphate receptor (InsP3R). However, ryanodine 10 micromol/L, an inhibitor of calcium-induced calcium release (CICR), did not inhibit the effect of SNP-induced increase of STOC. Methylene blue (1 micromol/L), an inhibitor of soluble guanylate cyclase, also inhibited such an effect. CONCLUSION: The increase of IK(Ca) caused by SNP may be mediated by cGMP via IP3-sensitive calcium pools, however, extracellular Ca2+ may not be involved in the process.

Animals↗