Biomedical subjects

Min Liu

Publications and source records attributed to Min Liu.

At least 109 records · Page 6Linked to original sources

PubMed2005

[Forensic applications of the sequencing of mitochondrial DNA cytochrome oxidase subunit I and II gene for idenfication of Sarcosaphagous flies (diptera)].

OBJECTIVE: This study was based on a 278 and 635 bp region of the gene for cytochrome oxidase subunit I and I (CO I and CO II ) encoding region of mtDNA; the aim was to solve the problems in identifying Sarcosaphagous flies, particularly in the flies' larvae and eggs which could not be identified only by use of their morphologyical features. METHODS: Samples of sarcosaphagous flies and larvae were collected from those on the corps of rabbits on the grassland in the Huhhot district and of a pig on the sandy ground in the Dunhuang district. The mtDNA of flies and their larvae and eggs was extracted using the Chelex technique. Polymerase chain reactions were conducted on a Perkin-Elmer 9600 thermal cycler, followed by vertical non-denaturing polyacrylamide gelectrophoresis. PCR products were purified using the Nucleic Acid Purification Kit. Sequences of both strands were obtained by direct sequencing of the double-stranded PCR product using one of the PCR primers and the ABI PRISM Big Dye Terminator Cycle Sequencing Kit. Sequence reactions were electrophoresed on ABI Model 377 DNA Sequencers. A neighbour-joining tree using the Tamura and Nei model of nucleotide substitution was constructed using the MEGA2. 1 package. RESULTS: A 278 and 635 bp region of the gene for CO I and CO II encoding region of mtDNA of Sarcosaphagous flies and their larvae and eggs was noted to show the percentages for the sequence divergence within species (less than 1%) and the sequence divergence between species (above 3%). For species that diverged from all others by a relatively large percentage and had small within-species variation, the least percentages of sequence divergence were given which distinguished any individual within that species from any other species. CONCLUSION: A 278 and 635 bp region of the gene for CO I and CO II encoding region of mtDNA of Sarcosaphagous flies and their larvae and eggs has been effectively used for the molecular phylogeny and the identification of their species group. CO I and CO II, or CO II, is better than CO I.

Animals↗

PubMed2005

Specific features of the contact history of probable cases of severe acute respiratory syndrome.

OBJECTIVE: To describe the specific features of the contact history of probable cases of severe acute respiratory syndrome (SARS) in Beijing. METHODS: Data of SARS cases notified from the Beijing Municipal Center for Disease Control and Prevention (BCDC) and supplemented by other channels were collected. All the data were analyzed by descriptive epidemiology. RESULTS: (1) The number of probable cases with contact history was significantly higher than the excluded cases. (2) The proportion of probable cases with contact history descended with epidemic development, but this situation did not occur in health care workers (HCWs). (3) The fatality rate of probable cases with contact history was significantly higher than the cases without contact history (OR = 1.489). (4) The proportion of probable cases with contact history was 85.86% among health care workers, which was significantly higher than that of non-health care workers (85.86% v.s. 56.44%, OR=4.69). CONCLUSIONS: (1) The susceptible persons with contact history may not get infected, and the contact history is just a sufficient condition of infecting SARS; (2) There are 3 conceivable reasons for the descending trend of the proportion in probable cases with contact history; (3) The contact history is one of the risk factors of the death of SARS cases; (4) The risk of contacting with SARS among health care workers is approximately 5 times higher than that of non-HCWs.

China↗

PubMed2005

Assessment of impacts of public health interventions on the SARS epidemic in Beijing in terms of the intervals between its symptom onset, hospital admission, and notification.

OBJECTIVES: To assess the impacts of public health interventions on the outbreak of SARS in Beijing by analyzing the intervals between symptom onset, hospital admission and notification of its cases. METHODS: Data of SARS cases reported from the Beijing Municipal Centers for Disease Prevention and Control (BCDC) were collected and analyzed by descriptive epidemiology. RESULTS: In the early epidemic period, the intervals between the disease onset and the hospital admission seemed irregular, so was the intervals between the hospital admission and the notification. After the middle ten days of April, the intervals turned out to be more regular, and the disordered situation in terms of the hospital admission and the case notification was gradually brought under control. CONCLUSIONS: Public health interventions against SARS has revealed positive impacts on SARS control program in Beijing. The timing and sensitivity of epidemic information reporting systems has been greatly improved in Beijing as a result of successful fight against this disease.

Adult↗

PubMed2005

[Study on the effectiveness and cost-benefit of influenza vaccine on elderly population in Beijing city].

OBJECTIVE: To estimate the effectiveness of inactivated influenza vaccine in elderly population. METHODS: An quasi-experimental study was used. 590 elderly people who volunteered to receive the influenza vaccine were served as vaccine group, while 602 persons who did not want to receive the inoculation but could match the vaccine group were served as controls. One baseline and three follow-up surveys were carried out. RESULTS: The protective rates of influenza like ill (ILI) as 52.38%, 36.84% and 37.89% with the decreasing rates of visits to ILI clinic as 45.16%, 50.54% and 50.54% were found after 1 month, 3 month and 6 month of inoculation of influenza vaccine; The protective rates of common cold, other respiratory tract or chronic disease were 49.54%, 64.54%, and 38.82%, respectively. The benefit-cost ratio was 4.98:1 in elderly population. CONCLUSION: Influenza vaccination could decrease ILI incidence and recurrence rates of related chronic diseases on elderly population to provide better economic benefits for the elderly.

Aged↗

PubMed2005

[Study on emission spectrum of some single element hollow cathode lamps].

In this paper, the emission spectra of 13 kinds of elements were determined on 19 single element hollow cathode lamps. The spectral overlap was discovered among emission lines of some elements and resonance lines or non-resonance lines of other elements. The reason for producing this phenomena was discussed initially. The viewpoint that these single element lamps can be used to the multielement determination and as the light sources of simultaneous multi-elements determining atomic absorption spectrophotometer was put forward.

Cadmium↗

PubMed2005

[The effect of TLR4/NF-kappaB activation and LOX-1 on monocyte adhesion to endothelium].

OBJECTIVE: Recent studies have shown that Toll-like receptor 4 (TLR4), a mediator of for innate immune responses, is involved in the initiation and progression of atherosclerosis. TLR4 activation mediates the expression of chemokines and cytokines through activation of NF-kappaB. We investigated the expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), intercellular adhesion molecule-1 (CAM-1), E-selectin induced by TLR4/NF-kappaB in human umbilical vein endothelial cells (HUVECs), and their effects on adhesion of monocyte to HUVECs. METHODS: HUVECs were incubated with purified LPS for 24 h. TLR4, LOX-1, ICAM-1, E-selectin mRNA were measured by RT-PCR; the protein expression of TLR4, LOX-1 and activation of NF-kappaB were detected by Western blot; the adhesive percentage between HUVECs and monocytes was determined by direct counting. RESULTS: LPS (1 mg/L) not only enhanced expression of TLR4, activation of NF-kappaB and induction of LOX-1, ICAM-1, E-selectin expression, but also increased the percentage of monocyte adhesion to endothelium. Pretreatment of HUVECs with anti-LOX1, anti-ICAM-1 or anti E-selectin antibodies partly abolished the increase in monocyte adhesion to endothelium. NF-kappaB inhibitor CAPE suppressed LPS-induced these effects. CONCLUSION: TLR4/NF-kappaB plays an important role in monocyte-endothelium adhesion partly through upregulation of LOX-1, ICAM-1 and E-selection expression, which may provide a target for the treatment of atherosclerosis.

Cell Adhesion↗

PubMed2005

Case fatality rate of severe acute respiratory syndromes in Beijing.

OBJECTIVE: To describe the case fatality rate of SARS in Beijing. METHODS: Data of SARS cases notified from Beijing Center for Disease Control and Prevention (BCDC) and supplemented by other channels were collected. The data were analyzed by rate calculation. RESULTS: The case fatality rate of SARS in Beijing was 7.66%, and had an ascending trend while the age of cases was getting older, and a descending trend while the epidemic development. The case fatality rate in Beijing was lower than that in other main epidemic countries or regions. CONCLUSIONS: The risk of death increases with the increment of age of SARS patients. Beijing is successful in controlling and treating SARS.

Adolescent↗

PubMed2005

Epidemiological features of severe acute respiratory syndrome in Beijing urban and suburb areas in 2003.

OBJECTIVE: To describe the epidemiologic features of an outbreak of severe acute respiratory syndrome (SARS) in urban and suburb areas in Beijing and to explore their differences between these two areas. METHODS: Data of SARS cases were collected from daily notification of China Ministry of Health and a database of infectious diseases was established by the Beijing Municipal Center for Disease Prevention and Control (BCDC). All the data were put into dataset files by Microsoft Excel-2000 and analyzed with SPSS version 10.0 software. RESULTS: The respective urban incidence and mortality rate were 29.06 and 2.21 per 100,000, while the case fatality rate was 7.62%. In contrast, the respective suburb incidence and mortality rate were 10.61 and 0.78 per 100,000, and the case fatality rate was 7.32%. No significant differences were found in demographic characteristics between the urban and suburb areas. CONCLUSION: Beijing urban area suffered a more serious SARS epidemic than the suburb area in 2003.

Adolescent↗

PubMed2005

[Genomic analysis of a familial clustering of chronic hepatitis B patients].

OBJECTIVE: To investigate the peripheral blood monocyte (PBMC) gene expression profile in a familial clustering of patients with chronic hepatitis B (CHB). METHODS: cRNA prepared from PBMC in a family with 5 CHB patients and 4 normal controls was hybridized to high-density oligouncleotide arrays (HG-U133A 2.0 Human GeneChips, Affymetrix), which interrogate the expression of approximately 22,000 human ESTs. Primary image obtained from scanning was analysed with a DNT software package. Real-time PCR was employed to confirm the gene chip results. RESULTS: 55 genes out of 22,000 ESTs were identified differently. Among the 55 genes 14 showed increased expression and 41 showed decreased expression in the familial clustering CHB patients compared with those in normal controls. Most of the genes (57%) were involved in immunity, inflammation, apoptosis, signaling transduction, and cell cycle. CONCLUSION: These results suggest that the hosts with this broad range of gene expression alterations are susceptible to hepatic B infection.

Cluster Analysis↗

PubMed2005

[Study on differentially expressed genes of ulcerative colitis in the rat treated by herbs-partitioned moxibustion].

OBJECTIVE: To probe the mechanism of herbs-partitioned moxibustion for treatment of ulcerative colitis. METHODS: The rats with ulcerative colitis were randomly divided into 3 groups, normal control group, model group, and herbs-partitioned moxibustion group. The rats in the herbs-partitioned moxibustion group were treated by herbs-partitioned moxibustion at bilateral Tianshu (ST 25). BiostarR-40s gene chip was applied to detect the differentially expressed gene of their colonic tissues and fluorescence quantitative polymerase chain reaction was employed to confirm the results of the microarray analysis with interleukin-1 beta messenger RNA (IL-1beta mRNA) expression. RESULTS: Of 174 differential expression genes identified, 28 genes (including 7 known genes) elevated in rats of ulcerative colitis were down-regulated and 146 genes (including 42 known genes) reduced in the rat of ulcerative colitis were up-regulated after herbs-partitioned moxibustion treatment. CONCLUSION: Many abnormally expressed genes are involved in occurrence of ulcerative colitis and herbs-partitioned moxibustion can regulate expression of IL-1beta and other genes to exert therapeutic effect.

Animals↗

PubMed2005

[Clinical study on treatment of cirrhosis by different dosages of salvia injection].

OBJECTIVE: To find the optimal dosage of salvia injection (SI) on treating cirrhosis with hepatitis B virus (HBV). METHODS: 120 patients, whose diagnosis was confirmed as cirrhosis with HBV and differentiated by TCM typing as blood stasis blocking collaterals type, were divide into two groups. one was compensatory cirrhosis group (A group, 60 patients), another was decompensated cirrhosis group (B group, 60 patients). In each group, patients were selected and randomly divided by lottery method into the large (24 ml), middle (16 ml) and small dose (8 ml) of SI treated groups and control group. The primary treatment was same in all patients. The course of treatment was 60 days. The clinical symptoms and signs, and liver functional indexes as ALT and TBil, and liver fibrosis indexesas procollagen type III (PCIII), collagen type IV (CIV) and hyaluronic acid (HA), were measured before and after treatment. RESULTS: Different dosages of SI all could improve the clinical symptoms and decline the level of ALT, TBil, PC III, CIV and HA (P < 0. 05). Treatment of large dosages SI showed the best efficacy, superior to that of middle and small dosage of SI (P < 0.05), but no significant difference was found between the efficacy of the latter two (P > 0.05). The efficacy of SI to compensatory cirrhosis group was better than that of decompensated cirrhosis group (P < 0.05). CONCLUSION: The large dosage (24 ml) of SI have the best effect to treat the cirrhosis with BHV, particularly to patients with compensated cirrhosis.

Adult↗

PubMed2004

Consumption of a high-fat diet alters the homeostatic regulation of energy balance.

Humans in many countries are currently experiencing what has been called an epidemic of obesity. That is, the average body weight (and amount of fat stored in the body) is increasing over years, carrying with it a multitude of associated medical, psychological, and economic problems. While there is no shortage of possible causes of this epidemic, increased availability and consumption of high-fat (HF), calorically dense and generally quite palatable food is often touted as a likely culprit. In order to better assess the impact of consuming a diet with those qualities, we have developed a well-controlled animal model in which the effects of chronic consumption of a high-fat diet can be dissociated from those of becoming obese per se. Long-Evans rats are fed one of two semipurified pelleted diets, a HF diet that contains 20% fat by weight and a low-fat (LF) diet that contains 4% fat by weight. Pair-fed animals consume the HF diet but are limited to the daily caloric intake of LF rats. Another group receives pelleted chow. Relative to animals consuming diets low in fat, HF animals weigh more, have more carcass fat, are hyperinsulinemic and hyperleptinemic, and are insulin resistant. HF-fed animals, independent of whether they become obese or not, also have central insulin and MTII insensitivity. Finally, HF rats have a down-regulated hypothalamic apo A-IV system that could contribute to their hyperphagia.

Animals↗

PubMed2004

Apolipoprotein A-IV, food intake, and obesity.

Apolipoprotein A-IV (apo A-IV) is secreted by the intestine associated with chylomicron. Intestinal apo A-IV synthesis is stimulated by fat absorption, which is probably mediated by chylomicron formation. The stimulation of apo A-IV synthesis in the jejunum and ileum is attenuated by intravenous leptin infusion. Intestinal apo A-IV synthesis is also stimulated by a factor from the ileum, probably peptide tyrosine-tyrosine (PYY), which has been demonstrated to affect satiety. Apo A-IV has been proposed to physiologically control food intake, a function not shared by apo A-I, and this inhibitory effect is centrally mediated. Recently, apo A-IV was demonstrated in the hypothalamus. The hypothalamic apo A-IV level was reduced by food deprivation and restored by lipid feeding. Intracerebroventricular administration of apo A-IV antiserum increased feeding and decreased the hypothalamic apo A-IV mRNA level, implying that feeding is normally limited by endogenous apo A-IV. Central administration of neuropeptide Y (NPY) significantly increased hypothalamic apo A-IV mRNA levels in a dose-dependent manner. The stimulation of intestinal synthesis and secretion of apo A-IV by lipid absorption are rapid; thus, apo A-IV is capable of short-term regulation of food intake. Evidence also suggests apo A-IV's involvement in the long-term regulation of food intake and body weight. Chronic ingestion of high fat blunts the hypothalamic apo A-IV response to lipid feeding and may therefore explain why chronic intake of high fat predisposes animals and humans to obesity.

Adrenalectomy↗

PubMed2004

Enhancement of paclitaxel-induced microtubule stabilization, mitotic arrest, and apoptosis by the microtubule-targeting agent EM012.

EM012, a semisynthetic phthalideisoquinoline alkaloid, has been recently found to target microtubules and possess anti-cancer activity. In this study, we evaluated the effects of EM012 in combination with the classic microtubule-targeting agent paclitaxel. Our results demonstrated that EM012 enhanced the anti-proliferative activity of nanomolar concentrations of paclitaxel in human breast cancer (MCF7), prostate cancer (DU145), and non-small-cell lung cancer (A549) cells. Further studies revealed that EM012 increased the ability of nanomolar concentrations of paclitaxel to induce mitotic arrest and apoptosis, without affecting microtubule polymerization. In contrast, when micromolar concentrations of paclitaxel were used, EM012 promoted paclitaxel-induced microtubule polymerization both in vitro and in cultured cells. Nevertheless, EM012 enhanced the ability of nanomolar concentrations of paclitaxel to stabilize microtubules, as indicated by increased tubulin acetylation. Our results therefore suggest a therapeutic potential of EM012/paclitaxel combination in the management of human cancer and provide mechanistic insights into the combined effects of these two microtubule-targeting agents.

Antineoplastic Agents, Phytogenic↗

PubMed2004

Effects of yo-yo diet, caloric restriction, and olestra on tissue distribution of hexachlorobenzene.

Chlorinated hydrocarbons are lipophilic, toxic, and persistent in the environment and animal tissues. They enter the body in food and are stored in adipose tissue. Loss of body fat through caloric restriction mobilizes stored lipophilic xenobiotics and results in distribution to other tissues. We have studied the reversibility of this process in mice that followed a regimen of body weight cycling. Weight gain was followed by weight loss, a second gain, and a second loss ("yo-yo diet regimen"). We measured the distribution of orally gavaged [14C]hexachlorobenzene, which is sparingly metabolized. We found that weight cycling has different effects in different organs. Continued weight loss resulted in a threefold increase of 14C amount and concentration in the brain. After weight regain, 14C in the brain decreased but then increased again after a second weight loss. Weight loss resulted in an increase in the concentration of 14C in adipose tissue without changing the total amount in that tissue. Weight loss and regain resulted in an increase of 14C in the liver, which reflected an increase of fat in the liver. The regimen of weight gain and loss was repeated in mice gavaged with [14C]hexachlorobenzene, with one group receiving the nonabsorbable fat olestra in the diet. Combined dietary olestra and caloric restriction caused a 30-fold increase in the rate of excretion of 14C relative to an ad libitum diet or a reduced caloric diet alone. Distribution of 14C into the brain resulting from the restricted diet was reduced by 50% by dietary olestra.

Adipose Tissue↗

PubMed2004

C2-alpha-lactylthiamin diphosphate is an intermediate on the pathway of thiamin diphosphate-dependent pyruvate decarboxylation. Evidence on enzymes and models.

Thiamin diphosphate (ThDP)-dependent decarboxylations are usually assumed to proceed by a series of covalent intermediates, the first one being the C2-trimethylthiazolium adduct with pyruvate, C2-alpha-lactylthiamin diphosphate (LThDP). Herein is addressed whether such an intermediate is kinetically competent with the enzymatic turnover numbers. In model studies it is shown that the first-order rate constant for decarboxylation can indeed exceed 50 s(-1) in tetrahydrofuran as solvent, approximately 10(3) times faster than achieved in previous model systems. When racemic LThDP was exposed to the E91D yeast pyruvate decarboxylase variant, or to the E1 subunit of the pyruvate dehydrogenase complex (PDHc-E1) from Escherichia coli, it was partitioned between reversion to pyruvate and decarboxylation. Under steady-state conditions, the rate of these reactions is severely limited by the release of ThDP from the enzyme. Under pre-steady-state conditions, the rate constant for decarboxylation on exposure of LThDP to the E1 subunit of the pyruvate dehydrogenase complex was 0.4 s(-1), still more than a 100-fold slower than the turnover number. Because these experiments include binding, decarboxylation, and oxidation (for detection purposes), this is a lower limit on the rate constant for decarboxylation. The reasons for this slow reaction most likely include a slow conformational change of the free LThDP to the V conformation enforced by the enzyme. Between the results from model studies and those from the two enzymes, it is proposed that LThDP is indeed on the decarboxylation pathway of the two enzymes studied, and once LThDP is bound the protein needs to provide little assistance other than a low polarity environment.

Acetaldehyde↗

PubMed2004

La3+ uptake and its effect on the cytoskeleton in root protoplasts of Zea mays L.

La(3+) ions are known to antagonize Ca(2+) and are used as a Ca(2+) channel blocker but little is known on the direct effects of La(3+). Micromolar La(3+) concentrations promoted root growth while higher concentrations were inhibitory. The uptake of La(3+) in maize root protoplasts revealed a membrane binding component (0.14 and 0.44 pmol min(-1) protoplast(-1) for 100 and 1,000 microM La(3+)) followed by a slower concentration and time-dependent uptake. Uptake was reduced by Ca(2+), but had no substantial effect on other ions. La(3+) shifted microtubule organization from random to parallel but caused aggregation of microfilaments. Our data suggest that La(3+) is taken up into plant cells and affects growth via stabilization of the cytoskeleton.

Cytoskeleton↗

PubMed2004

Observation of dynamic solvent effect for electron tunneling in u-shaped molecules.

The electron-transfer rate constant is measured in two U-shaped donor-bridge-acceptor molecules over a wide range of temperature in acetonitrile and N-methylacetamide (NMA). The electron-transfer rate at high temperature can be well described by a nonadiabatic model of the reaction, but at low temperatures the rate in NMA becomes controlled by the solvent. The results are discussed in terms of theoretical models for the change in reaction mechanism and its dependence on the solute-solvent frictional coupling.

Journal Article↗