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Biomedical subjects

Ming Li

Publications and source records attributed to Ming Li.

At least 235 records · Page 13Linked to original sources
PubMed2005

[Expression of chemokine receptor CXCR4 and CCR7 in laryngeal carcinoma].

OBJECTIVE: This study was designed to observe the expression of CXCR4 and CCR7 in laryngeal carcinoma tissues in order to primitively clarify the relationship between Chemokine Receptor CCR7 and CXCR4 and the malignity of laryngeal carcinoma. It would be helpful to cure laryngeal carcinoma. METHOD: We examined the expression of Chemokine Receptor CXCR4 and CCR7 in 30 cases laryngeal carcinoma tissues (experiment group) and 18 cases normal laryngeal tissues (control group)with immunohistochemistry. And qualitative analysis of light microscopy with computer-assisted image system was employed. Then our conclusion was drawn from statistical analysis. RESULT: (1) Chemokine Receptor CXCR4 and CCR7 were positively expressed in laryngeal carcinoma tissues while they were negative in the control group. Their expressions were significantly higher than those of control group (P < 0.01).; (2) Chemokine Receptor CXCR4 and CCR7 expression in laryngeal carcinoma declined with the rise of the differentiation grade of laryngeal carcinoma (P < 0.05). The expression of CXCR4 and CCR7 were significantly higher in the group with lymph node metastasis than those without lymph node metastasis (P < 0.01). And the same results appeared between laryngeal carcinoma groups with different clinical stages (P < 0.01). CONCLUSION: Chemokine Receptor CXCR4 and CCR7 are highly expressed in laryngeal carcinoma, and their expression were associated with differentiation grade of laryngeal carcinoma, clinical stage and neck lymph node metastasis.

Adult↗
PubMed2005

[A field trial study on the influence of different salt iodine concentration on urinary iodine excrition among the target population].

OBJECTIVE: To evaluate the influence of different salt iodine concentration on urinary iodine excrition among the target population and to determine the appropriate level of salt iodization to the local people. METHODS: In the 31-day random control trial, 1099 subjects from 399 families were randomly distributed into four groups and were supplied with iodized-salt with different iodine concentration of (6 +/- 2)mg/kg, (15 +/- 2)mg/kg, (24 +/- 2)mg/kg and (34 +/- 2)mg/kg, respectively. The original family salt was retrieved, whose iodine content was determined in those subjects' families with single-blind method. Baseline survey was conducted including salt and urinary iodine of the subjects. From the 27th day after the intervention, the urinary samples of the subjects were continuously collected for 5 days and urinary iodine was tesed respectively. Meanwhile, daily meal investigation was conducted to evaluate the influences originated from food. RESULTS: The median of local water iodine content was 3.05 microg/L and the average salt iodine concentration was (36.4 +/- 5.4)mg/kg while 98.8% of the household consumed sufficient iodized-salt. The medians of baseline urinary iodine of the subjects were 293.6 microg/L in city, and 508.8 microg/L in the countryside. The urinary iodine medians of four groups in the day of 28th after intervention were 97.2 microg/L, 198.6 microg/L, 249.4 microg/L, and 330.7 microg/L respectively in the city group, while they were 100.5 microg/L, 193.0 microg/L, 246.3 microg/L and 308.3 microg/L seperately in the countryside group. There was no statistically significant differences among the medians of urine iodine in the 27th, 28th, 29th, 30th and 31st day after intervention (P > 0.05). CONCLUSIONS: The target areas were with iodine deficiency which possessed high coverage of qualified iodized-salt at household level. The average urinary iodine level of the subjects was slightly higher than the standard level, according to the baseline survey. The intervetion trail showed that the salt iodine concentration of 15-24 mg/kg was sufficient to the local people.

Adolescent↗
PubMed2005

Clinical observation on juvenile macular hole without trauma and hypermyopia.

PURPOSE: To investigate the clinical characteristics of juvenile macular hole without trauma and hypermyopia, and research the mechanism of macular hole. METHODS: Sixty-seven patients less than 40 years of age were studied retrospectively from June 1998 to March 2003. Five cases (7 eyes) aged from 22 to 38 years were reported and the clinical characteristics that had macular hole without trauma or hypermyopia were summed up. RESULTS: There was 1 male and 4 females with visual acuity from 0.08 to 0.8. The images of optical coherence tomography (OCT) showed full thickness macular hole in 5 patients (7 eyes), and the diameters were from 87 to 1043 microm. Among them, 2 cases were combined with retina pigmentosa; 1 case with binocular Coat's disease; 1 case had bilateral macular hole combined with Eagles' disease; 1 case was combined with 2-2.5PD old retinochoroidal lesion under middle-peripheral fundus, and 1.5 PD retinal pigment epithelium (RPE) defect on the optical disk. CONCLUSION: The juvenile macular hole without trauma and hypermyopia combined the different retina vascular damages and the RPE defects.

Adult↗
PubMed2004

Crystallization and preliminary X-ray crystallographic analysis of osteoclast-stimulating factor.

Osteoclast-stimulating factor increases osteoclast formation and bone resorption through a cellular signal transduction cascade, possibly by its interaction with c-Src or related family members. Crystals of human osteoclast-stimulating factor were obtained by the hanging-drop vapour-diffusion method using ammonium sulfate as a precipitant. The crystals are primitive orthorhombic and belong to P222 or a related space group, with unit-cell parameters a = 38.1, b = 54.9, c = 64.7 A.

Base Sequence↗
PubMed2004

[Association of polymorphisms in testosterone 5-alpha-reductase II genotype and prognosis factors of prostate cancer].

OBJECTIVE: The correlation were studied between testosterone 5-alpha-reductase II (SRD5A2) gene polymorphisms and prognosis factors. METHODS: V89L and A49T variants was identified with Mwo1 and Rsa1. The differences of V89L and A49T between cancer of prostate (CaP) and benign prostatic hyperplasia (BPH) were studied. In addition, we also researched the association of polymorphisms with age of onset, free prostate specific antigen (FPSA), total PSA (TPSA), FPSA/TPSA (F/T), Gleason score, and T stage in cancer group. RESULTS: We found no differences of V89L and A49T polymorphisms between CaP and BPH. In CaP group the A49T variant was associated with lower age of onset (P = 0.03) and higher Gleason score (P = 0.015). There were no differences between VV and VL+LL polymorphisms with any of the characteristics studied. When the characteristics above were regarded as two-level discrete variable, there were no differences by A49T and V89Lvariants. CONCLUSION: In CaP group, the AT+TT genotype was perhaps associated with poor prognosis. VL+LL genotype has no relation with prognosis.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2004

A new arginine substitution mutation of DSRAD gene in a Chinese family with dyschromatosis symmetrica hereditaria.

BACKGROUND: Dyschromatosis symmetrica hereditaria (DSH) is a pigmentary genodermatosis of autosomal dominant inheritance characterized by a mixture of hyperpigmented and hypopigmented macules distributed on the dorsal aspects of the hands and feet. To date, only three articles testified that DSH is caused by the mutations of DSRAD gene (also called ADAR1) encoding for RNA-specific adenosine deaminase. OBJECTIVE: To identify mutations of DSRAD as the disease-causing gene and recognize different mutations giving a clue to insight into the mechanism of DSH. METHODS: We collected a Chinese DSH family consisting of a total of 11 individuals including five DSH patients (three males and two females). The whole coding region of DSRAD was amplified by polymerase chain reaction and products analyzed by direct sequencing. RESULTS: We detected a transition, 3463 C>T, leading to a missense mutation (R1155W) in genomic DNAs of five patients, and the point mutation was not found in normal individuals in this DSH family and in 100 unrelated, population-match control individuals. CONCLUSION: Our data suggests that R1155W missense mutation is a new mutation in exon 15 of DSRAD gene and further testify that DSRAD gene is the pathogenic gene of DSH.

Adenosine Deaminase↗
PubMed2004

Inhibition of integrin-mediated adhesion and signaling disrupts retinal development.

Integrins are the major family of cell adhesion receptors that mediate cell adhesion to the extracellular matrix (ECM). Integrin-mediated adhesion and signaling play essential roles in neural development. In this study, we have used echistatin, an RGD-containing short monomeric disintegrin, to investigate the role of integrin-mediated adhesion and signaling during retinal development in Xenopus. Application of echistatin to Xenopus retinal-derived XR1 glial cells inhibited the three stages of integrin-mediated adhesion: cell attachment, cell spreading, and formation of focal adhesions and stress fibers. XR1 cell attachment and spreading increased tyrosine phosphorylation of paxillin, a focal adhesion associated protein, while echistatin significantly decreased phosphorylation levels of paxillin. Application of echistatin or beta(1) integrin function blocking antibody to the embryonic Xenopus retina disrupted retinal lamination and produced rosette structures with ectopic photoreceptors in the outer retina. These results indicate that integrin-mediated cell-ECM interactions play a critical role in cell adhesion, migration, and morphogenesis during vertebrate retinal development.

Animals↗
PubMed2004

Adjust quality scores from alignment and improve sequencing accuracy.

In shotgun sequencing, statistical reconstruction of a consensus from alignment requires a model of measurement error. Churchill and Waterman proposed one such model and an expectation-maximization (EM) algorithm to estimate sequencing error rates for each assembly matrix. Ewing and Green defined Phred quality scores for base-calling from sequencing traces by training a model on a large amount of data. However, sample preparations and sequencing machines may work under different conditions in practice and therefore quality scores need to be adjusted. Moreover, the information given by quality scores is incomplete in the sense that they do not describe error patterns. We observe that each nucleotide base has its specific error pattern that varies across the range of quality values. We develop models of measurement error for shotgun sequencing by combining the two perspectives above. We propose a logistic model taking quality scores as covariates. The model is trained by a procedure combining an EM algorithm and model selection techniques. The training results in calibration of quality values and leads to a more accurate construction of consensus. Besides Phred scores obtained from ABI sequencers, we apply the same technique to calibrate quality values that come along with Beckman sequencers.

Algorithms↗
PubMed2004

Lack of effects of postnatal exposure to a mixture of aryl hydrocarbon-receptor agonists on the development of methylnitrosourea-induced mammary tumors in sprague-dawley rats.

There are concerns that early life exposure to organochlorines, including aryl hydrocarbon receptor (AhR) agonists, may lead to long-term effects and increase the risk of developing breast cancer. Our objective was to test if postnatal exposure to a mixture of 2,3,7,8-tetrachlorodibenzodioxin (TCDD)-like chemicals would modulate the development of methylnitrosourea (MNU)-induced mammary tumors. Females received by gavage a mixture containing 3 non-ortho-polychlorinated biphenyls (PCBs), 6 polychlorinated dibenzodioxins (PCDDs), and 7 polychlorinated dibenzofurans (PCDFs), at 1, 5, 10, 15, and 20d of age. The doses were equivalent to 0, 1, 10, 100, or 1000 times the amount ingested through breast milk by a human infant during its first 24 d of life. Subgroups of 1000 x reated rats and controls were sacrificed at 21 d of age for assessment of mammary-gland development, cell death, and proliferation. Mammary-tumor development was assessed in MNU (30 mg/kg body weight ip at 50 days of age)-induced rats pre-exposed to the mixture (MNU-0, MNU-1, MNU-10, MNU-100, MNU-1000). Rats were sacrificed when their mammary tumors reached 1 cm in diameter, or when the rats reached > or = 32 wk of age. Mammary-gland whole mounts were analyzed with all palpable and microscopic lesions (n = 1563) histologically classified and grouped as benign, intraductal proliferations, or malignant. There were no marked effects on age at onset of puberty (vaginal opening) and estrous cyclicity. Despite a significant decrease in proliferating cell nuclear antigen (PCNA)-positive mammary cells in 1000 x treated 21-d-old rats, there were no long-term dose-response effects on mammary-gland morphology and tumor development. In conclusion, postnatal exposure to the mixture of AhR agonists had no significant effects on the development of MNU-initiated mammary tumors.

Age Factors↗
PubMed2004

[Exploration on endovascular treatment for disorders of great vessels].

OBJECTIVE: To explore the efficacy and shortcoming of endovascular therapy with mainly endovascular graft in treating disorders occurring in the thoracic or thoracoabdominal aorta. METHODS: Total 137 cases with great vessel disorders including dissections, aneurysm, pseudoaneurysm, aortic deceleration injury and coarctation were treated by endovascular technique. The lowest lesion located between the celiac and mesenteric arteries. RESULTS: Two cases underwent emergent surgery due to acute visceral arterial insufficiency. Seven cases had early endoleaks. After a follow-up of 1 - 43 (average of 11) months, 2 late endoleaks were detected; 5 patients died, 4 of them were due to endograft unrelated diseases, one due to a recurrent multiple aneurysms. CONCLUSION: Endovascular treatment is relatively safe and effective for treating high risky patients with lesions occurring in the great vessels and seems to have a prospective future, although the device needs to be further improved and the long-term efficacy should be confirmed.

Angioplasty↗
PubMed2004

tPatternHunter: gapped, fast and sensitive translated homology search.

UNLABELLED: New ideas, spaced seeds and gapped alignment before 6-frame translation are implemented for translated homology search in tPatternHunter. The new software compares favorably with tBLASTx. AVAILABILITY: The software is free to academics at http://www.bioinformaticssolutions.com/downloads/ph-academic/ CONTACT: bma@csd.uwo.ca.

Algorithms↗
PubMed2004

Widespread activation of antibiotic biosynthesis by S-adenosylmethionine in streptomycetes.

The effect of S-adenosylmethionine (SAM) on the production of various antibiotics was investigated to determine whether SAM-dependent methylation is required in biosynthetic pathways of antibiotics. Pristinamycin II(B) and granaticin do not require SAM-dependent methylation in their biosynthesis pathways, and production of these two antibiotics was increased about 2-fold when a low concentration (50 and 10 microM, respectively) of SAM was treated; in contrast, oleandomycin and avermectin B1a require SAM as a methyl donor in their biosynthesis, and production of these two antibiotics was increased 5-fold and 6-fold, depending on the SAM concentration within a certain range. We also found that the transcription of a pathway-specific regulator, gra-ORF9, was activated by exogenous SAM treatment. Production of oleandomycin and avermectin B1a was decreased by using a methyltransferase inhibitor, sinefungin, but the production levels of these antibiotics were restored to the control level by simultaneously adding SAM and sinefungin. Interestingly, we have found a similar stimulatory effect of S-adenosylhomocysteine (SAH), the methylation product of SAM, on antibiotic production in the four strains. Our results clearly demonstrate the widespread activation of antibiotic production using SAM in streptomycetes.

Anti-Bacterial Agents↗
PubMed2004

A vaccinia replication system for producing recombinant hepatitis C virus.

AIM: To develop a cell culture system capable of producing high titer hepatitis C virus (HCV) stocks with recombinant vaccinia viruses as helpers. METHODS: Two plasmids were used for the generation of recombinant HCV: one containing the full-length HCV cDNA cloned between T7 promoter and T7 terminator of pOCUS-T7 vector, and the other containing the HCV polyprotein open reading frame (ORF) directly linked to a vaccinia late promoter in PSC59. These two plasmids were co-transfected into BHK21 cells, which were then infected with vTF7-3 recombinant vaccinia helper viruses. RESULTS: After 5 d of incubation, approximately 3.6X10(7) copies of HCV RNA were present per milliliter of cell culture supernatant, as detected by fluorescence quantitative RT-PCR (FQ-PCR). The yield of recombinant HCV using this cell system increased 100- to 1 000- fold compared to in vitro- transcribed HCV genomic RNA or selective subgenomic HCV RNA molecule method. CONCLUSION: This cell culture system is capable of producing high titer recombinant HCV.

Animals↗
PubMed2004

Effects of typical and atypical antipsychotic drugs on maternal behavior in postpartum female rats.

Understanding the effects of antipsychotic drugs (APDs) on social behaviors such as maternal behavior is valuable for understanding the complete spectrum of therapeutic and side-effects of antipsychotics. Although previous studies have suggested that typical antipsychotics impair maternal behavior, the effects of the atypical antipsychotics have not been systematically explored. The purpose of the present report was to examine the effects of typical (haloperidol, HAL) and several atypical (clozapine, CLZ; risperidone, RIS; quetiapine, QUE) antipsychotics on maternal behavior in female rats. Maternal behaviors were examined repeatedly over a period of 24 h after a single injection of a range of doses of HAL, CLZ, RIS or QUE on Day 6 postpartum. All antipsychotic drugs, typical or atypical, elicited a qualitatively similar disruptive effect on the active components of maternal behavior such as pup approach, pup retrieval and nest building at clinically relevant doses. However, HAL caused a prolonged disruption, whereas CLZ, RIS and QUE induced an early onset but shorter duration disruption. In addition, only the atypical antipsychotics showed some inhibitory effects on nursing behavior, possibly due to sedative side-effects shared by all atypical antipsychotics. The current generation of atypical antipsychotics shows a disruptive influence on maternal behavior similar to that of the typical antipsychotics. This effect may be intrinsic to antipsychotic activity or may be reflective of a side-effect. Since the latter is more likely, this may be an effect to avoid in the design of future antipsychotics.

Animals↗
PubMed2004

Localization of mitotic arrest deficient 1 (MAD1) in mouse oocytes during the first meiosis and its functions as a spindle checkpoint protein.

The present study was designed to investigate the localization of mitotic arrest deficient 1 (MAD1) in mouse oocytes during meiotic maturation and its relationship with kinetochores, chromosomes, and microtubules. Oocytes at various stages during the first meiosis were fixed and immunostained for MAD1, kinetochores, microtubules, and chromosomes. The stained oocytes were examined by confocal microscopy. Some oocytes were treated with nocodazole or Taxol before examination. The anti-MAD1 antibody was injected into the oocytes at the germinal vesicle (GV) stage for examination of chromosome alignment and spindle formation. It was found that MAD1 was present in the oocytes from the GV to prometaphase I stages around the nuclei. When the oocytes reached the metaphase I (M-I) to metaphase II (M-II) stages, MAD1 was mainly localized at the spindle poles. However, MAD1 relocated to the vicinity of the chromosomes when spindles were disassembled by nocodazole or cooling, and the relocated MAD1 moved back to the spindle poles during spindle recovery. Taxol treatment did not affect the MAD1 localization. Although anti-MAD1 antibody injection did not affect nuclear maturation, significantly higher proportions of injected oocytes had misaligned chromosomes when the oocytes reached the M-I to M-II stages. The results of the present study indicate that MAD1 is present in mouse oocytes at all stages during the first meiosis and that it participates in spindle checkpoint during meiosis. However, MAD1 could not check misaligned chromosomes during spindle recovery after the spindles were destroyed by drug or cooling, which caused some chromosomes to scatter in the oocytes.

Animals↗
PubMed2004

Discovering patterns to extract protein-protein interactions from full texts.

MOTIVATION: Although there are several databases storing protein-protein interactions, most such data still exist only in the scientific literature. They are scattered in scientific literature written in natural languages, defying data mining efforts. Much time and labor have to be spent on extracting protein pathways from literature. Our aim is to develop a robust and powerful methodology to mine protein-protein interactions from biomedical texts. RESULTS: We present a novel and robust approach for extracting protein-protein interactions from literature. Our method uses a dynamic programming algorithm to compute distinguishing patterns by aligning relevant sentences and key verbs that describe protein interactions. A matching algorithm is designed to extract the interactions between proteins. Equipped only with a dictionary of protein names, our system achieves a recall rate of 80.0% and precision rate of 80.5%. AVAILABILITY: The program is available on request from the authors.

Algorithms↗