Biomedical subjects

Jing Luo

Publications and source records attributed to Jing Luo.

34 records · Page 2Linked to original sources

PubMed2004

Evolution and biogeography of talpid moles from continental East Asia and the Japanese islands inferred from mitochondrial and nuclear gene sequences.

We sequenced the cytochrome b gene from two little-studied mammal species from the highlands of Southwest China, the long-tailed mole Scaptonyx fusicaudus and the gracile shrew-like mole Uropsilus gracilis. This data was used to examine the phylogenetic relationships among 19 talpid species within the family Talpidae (Mammalia: Eulipotyphla). Cytochrome b gene trees supported a basal placement of shrew-like moles (Uropsilus) within the Talpidae, and suggested that fossorial specializations arose twice during talpid evolution. To assess the evolutionary relationships of moles endemic to this region, we additionally sequenced the 12S rRNA gene and the nuclear recombination-activating gene-1 from eight and ten East Asian taxa, respectively. Analyses of these single and concatenated data sets suggested that East Asian shrew moles diverged prior to the evolution of fossorial Eurasian moles. However, we were unable to determine whether semi-fossorial shrew moles are monophyletic. In contrast, fossorial Eurasian genera (Talpa, Mogera and Euroscaptor) were consistently found to form a monophyletic clade, with Mogera and Euroscaptor representing sister taxa. Furthermore, this fossorial clade grouped with the semi-aquatic Desmana, although with fairly low (35-62%) bootstrap support. Mogera imaizumii was found to be more closely related to M. wogura than to M. tokudae. This implies that the ancestors of these three species entered Japan from the Asian continent in this order via a series of migration events, suggesting that the Japanese Islands have played an important role in preserving mole lineages from ancient to recent times.

Animals↗

PubMed2004

Precuneus contributes to attentive control of finger movement.

AIM: To examine whether precuneus subserves the attentive control of finger movement or whether it mediates the movement preparation and motor inhibition. METHODS: In the Preparation Stage, subjects were shown with a 5-number string in which each number stood for a key-pressing response, the number strings included a complex pattern (eg, 4-1-4-2-3), or a simple one (eg, 2-2-2-2-2), or a null one (ie, x-x-x-x-x). In the Execution Stage, five reaction signs were presented one by one and subjects were required to press the corresponding key to each sign sequentially (eg, in the 4-1-4-2-3 preparation example, subjects press key 4 to the first sign, press key 1 to the second sign, key 4 to the third sign and so on). For the null preparation pattern, five numbers, rather than the reaction signs, were shown at the same pace as in the other two conditions and subjects were to press the corresponding keys. RESULTS: Left medial frontal gyrus (BA 6) and precentral gyrus (BA 6) were involved in both of the Preparation Stage and the Execution Stage, whereas left precuneus (BA 7) was activated only in the Execution Stage. CONCLUSION: Precuneus mediates the attentive control of finger movement, but not the movement preparation or motor inhibition.

Adult↗

PubMed2004

[Percutaneous lung cancer cryotherapy guided by computer tomography].

OBJECTIVE: To document the feasibility, safety and efficacy of percutaneous lung cancer cryotherapy (PLC) guided by Computer Tomography (CT). METHODS: Two hundred and thirty seven patients with lung cancer underwent CT-guided PLC from August, 2001 to April, 2003. CT-visualized immediate ice formation beyond tumor margins was compared to tumor size and location. PLC feasibility and safety were evaluated. CT scan, lung tissue biopsy and survival rate were observed at different stages postcryoablation. RESULTS: All the patients underwent PLC using local anesthesia with minimal or no sedation. Iceball formation was well seen as negative Hounsfield units within soft tissue masses. Tumor size and location were independent determinants of ice coverage which was 97% (n = 124) for masses < 4 cm in diameter, and 80% (n = 183) for masses > 4 cm in diameter (P < 0.01). Only 59 patients had transient mild hypertension, and no death occurred during cryotherapy. Most of the slight side-effects were self-limited. No major bleeding or bronchial sequelae were identified. CT scan showed that necrotic cavitation larger than the original mass developed in 78% of the cases within one week, and mostly resolved by 6 months (4%). Partial resolution + complete resolution was noted by 1 - 6 months, which demonstrated reduced or stable tumor size. Necrotic coagulation could be found within 1 month and fibrin scarring 3 months postcryoablation. The survival rate in 18 months was 86% for patients at an early stage of lung cancer, and 21% for patients at stage III, while the one year survival rate for patients at stage IV was 9%. CONCLUSION: CT-guided PLC, with minimal procedure associated morbidity or sequelae, is a promising treatment for lung neoplasm of any stage in nearly any location.

Adenocarcinoma↗

PubMed2004

[Predictive value of drug resistance-related genes expression in neoadjuvant chemotherapy in patients with non-small cell lung cancer of stage III].

BACKGROUND & OBJECTIVE: P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP), and lung resistant protein (LRP) play important roles in multidrug resistance (MDR). This study was to determine P-gp, MRP, and LRP expression in patients with non-small cell lung cancer (NSCLC) of stage III, and evaluate their predictive value in neoadjuvant chemotherapy. METHODS: Immunohistochemical analyses were performed on 31 patients with NSCLC of stage III before, and after neoadjuvant chemotherapy. RESULTS: The frequency of P-gp, MRP, and LRP expression were 29.0% (9/31), 45.2% (14/31), and 38.7% (12/31) before chemotherapy, and were 61.3% (19/31), 51.6% (16/31), and 41.9% (13/31) after chemotherapy. Of 31 patients, 10 (10/31, 32.3%) expressed both MRP and LRP before chemotherapy, which indicated significant positive correlation between MRP and LRP expression (r=0.061, P< 0.001). In patients with P-gp, MRP, or LRP expression before chemotherapy, the response rates towards chemotherapy were 44.4% (4/9), 28.6% (4/14), and 16.7% (2/12). Of 10 patients with both MRP and LRP expression, only 1 (1/10, 10.0%) responded to chemotherapy. The median survival time of patients who responded to chemotherapy was 31 months, while that of patients who did not responded to chemotherapy was 15 months, that of patients who didn't receive neoadjuvant chemotherapy before surgery was 18 months. CONCLUSION: Patients with both MRP and LRP expression are probably resistant to chemotherapy, the value of neoadjuvant chemotherapy is limit in such patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2004

Effects of chlorogenic acid, an active compound activating calcineurin, purified from Flos Lonicerae on macrophage.

AIM: To investigate the activation of chlorogenic acid (CHA) purified from Flos Lonicerae to calcineurin and its effects on macrophage functions in vivo and in vitro. METHODS: According to the screening results that Flos Lonicerae could activate calcineurin, the active component which could activate calcineurin was purified from Flos Lonicerae by column chromatography on silica gel and identified as CHA. The activation of CHA on calcineurin had been validated with both p-NPP and 32P-labeled RII peptide as the substrates. The clearance of charcoal particles in normal mice and the cytotoxicity of U937 to MCF-7 were used together to determine the effects of CHA on macrophage functions. RESULTS: CHA could activate calcineurin, and the concentration of CHA on maximal activating calcineurin was 282.5 micromol/L. CHA administration (10 mg/kg, ig, 7 d) significantly enhanced the macrophage functions in normal mice. CHA (70.6, 141.2, and 282.5 micromol/L) obviously increased the cytotoxicity of U937 to MCF-7. CONCLUSION: CHA could activate calcineurin and enhance the macrophage functions in vivo and in vitro, and its functions in vivo may be realized via the signal pathways of calcineurin.

Animals↗

PubMed2003

Examination of hydrophobic contaminant adsorption in mineral micropores with grand canonical Monte Carlo simulations.

A molecular level understanding of the interactions between hydrophobic organic contaminants (HOCs) and sediments is needed in order to assess contaminant fate in the environment. Grand canonical Monte Carlo simulations were performed to investigate water and trichloroethylene (TCE) adsorption in slit micropores confined by charged and uncharged silica surfaces. Gas-phase single-sorbate simulations with water or TCE were performed as well as mixture simulations of bulk water containing TCE at 1% of its saturation concentration. Gas-phase isosteric heats for water adsorption in the uncharged pores ranged from -40 to -52 kJ/mol, and the densities of the adsorbed water phases were always less than that for bulk water. Gas-phase isosteric heats for water adsorption in the charged pores ranged from -79 to -170 kJ/mol, and the densities of the adsorbed water phases were close to that for bulk water. The isosteric heats and water densities indicated that the uncharged pores were mildly hydrophobic, and the charged pores were very hydrophilic. In mixture simulations of adsorption from solution, the presence of water promoted TCE adsorption in uncharged pores with widths between 14 and 20 A. The isosteric heats for TCE adsorption from solution ranged from -14 to -27 kJ/mol in the uncharged pores and from -9.3 to -50 kJ/mol in the charged pores. Strong attractions to the pore surfaces were significantly diminished after adsorption of the first two monolayers of either adsorbate. Aqueous-phase TCE at a concentration equal to 1% of its saturation concentration was able to completely displace adsorbed water in uncharged pores. Even in highly hydrophilic pores, TCE at this concentration was able to displace up to 50% of the adsorbed water. Apparent differential enthalpies of adsorption determined from the temperature dependence of TCE adsorption isotherms underestimated the magnitude of the true isosteric heats of adsorption by up to 30 kJ/mol. This shows that HOC adsorption enthalpies determined from the temperature dependence of their adsorption isotherms underestimate the true strength of HOC-adsorbent interactions.

Adsorption↗

PubMed2003

Function of hippocampus in "insight" of problem solving.

Since the work of Wolfgang Kohler, the process of "insight" in problem solving has been the subject of considerable investigation. Yet, the neural correlates of "insight" remain unknown. Theoretically, "insight" means the reorientation of one's thinking, including breaking of the unwarranted "fixation" and forming of novel, task-related associations among the old nodes of concepts or cognitive skills. Processes closely related to these aspects have been implicated in the hippocampus. In this research, the neural correlates of "insight" were investigated using Japanese riddles, by imaging the answer presentation and comprehension events, just after participants failed to resolve them. The results of event-related functional magnetic resonance imaging (fMRI) analysis demonstrated that the right hippocampus was critically highlighted and that a wide cerebral cortex was also involved in this "insight" event. To the best of our knowledge, this work is the first neuroimaging study to have investigated the neural correlates of "insight" in problem solving.

Adult↗

PubMed2003

The effect of calcineurin activator, extracted from Chinese herbal medicine, on memory and immunity in mice.

Calcineurin (CN) is a highly abundant phosphatase in the brain and it is the only Ca(2+)- and calmodulin-dependent protein serine/threonine phosphatase. There is considerable evidence to suggest that CN plays an essential role in activity-dependent modulation of synaptic efficacy. It has been shown recently that inhibitors of CN, such as CsA or FK506, impair memory formation in day-old chicks. In our present study, extract of Fructus cannabis (EFC) with activation of CN, extracted from Chinese traditional medicine, was used to determine the effects on memory and immunity. In the step-down-type passive avoidance test, the plant extract (0.2 g/kg) significantly improved amnesia induced by chemical drugs in mice, and greatly enhanced the ability of cell-mediated type hypersensitivity and nonspecific immune responses in normal mice. The present study provided pharmacological evidence for Chinese herbal medicine screening from molecular model.

Amnesia, Transient Global↗

PubMed2003

The lasting impression of chairman Mao: hyperfidelity of familiar-face memory.

We examined the accuracy of a highly-familiar-face representation in memory. In experiment 1, a famous portrait of Chairman Mao was digitally altered in terms of the distance between his two eyes, two pixels at a time. Mainland Chinese adults were shown the original or altered photos, one at a time, and asked to determine whether each was that of Chairman Mao or altered. Eastern Asian and Caucasian participants, who were unfamiliar with Mao's photo, were shown simultaneously the original face paired with the altered ones and asked to determine whether the photos were identical. The Mainland Chinese participants' memory threshold approximated the perceptual discrimination threshold of the Eastern Asian and Caucasian participants. Experiments 2 and 3 ruled out that the result of experiment I was due to artifacts of photographic alteration. The findings of the present study suggest that our memory of a very familiar face is highly accurate, at least in terms of the interocular configuration. The accuracy is perhaps only limited by the perceptual resolution capacity of our visual system.

Adult↗

PubMed2003

Extract from Fructus cannabis activating calcineurin improved learning and memory in mice with chemical drug-induced dysmnesia.

AIM: To investigate the effects of extract from Fructus cannabis (EFC) that can activate calcineurin on learning and memory impairment induced by chemical drugs in mice. METHODS: Bovine brain calcineurin and calmodulin were isolated from frozen tissues. The activity of calcineurin was assayed using p-nitrophenyl phosphate (PNPP) as the substrate. Step-down type passive avoidance test and water maze were used together to determine the effects of EFC on learning and memory dysfunction. RESULTS: EFC activated calcineurin activity at a concentration range of 0.01-100 g/L. The maximal value of EFC on calcineurin activity (35 %+/-5 %) appeared at a concentration of 10 g/L. The chemical drugs such as scopolamine, sodium nitrite, and 45 % ethanol, and sodium pentobarbital induced learning and memory dysfunction. EFC administration (0.2, 0.4, and 0.8 g/kg, igx7 d) prolonged the latency and decreased the number of errors in the step-down test. EFC, given for 7 d, enhanced the spatial resolution of amnesic mice in water maze test. EFC overcome amnesia of three stages of memory process at the dose of 0.2 g/kg. CONCLUSION: EFC with an activation role of calcineurin can improve the impaired learning and memory induced by chemical drugs in mice.

Animals↗

PubMed2002

Genetic evidence for an East Asian origin of domestic dogs.

The origin of the domestic dog from wolves has been established, but the number of founding events, as well as where and when these occurred, is not known. To address these questions, we examined the mitochondrial DNA (mtDNA) sequence variation among 654 domestic dogs representing all major dog populations worldwide. Although our data indicate several maternal origins from wolf, >95% of all sequences belonged to three phylogenetic groups universally represented at similar frequencies, suggesting a common origin from a single gene pool for all dog populations. A larger genetic variation in East Asia than in other regions and the pattern of phylogeographic variation suggest an East Asian origin for the domestic dog, approximately 15,000 years ago.

Animals↗

PubMed2002

Experimental and molecular mechanics and ab initio investigation of activated adsorption and desorption of trichloroethylene in mineral micropores.

This research investigated activated adsorption of a hydrophobic organic contaminant(HOC) in mineral micropores using experimental and molecular modeling techniques. Adsorption of trichloroethylene (TCE) on a silica gel adsorbent was measured using a frontal analysis chromatography technique at atmospheric and elevated fluid pressures. Increasing the fluid pressure yielded increased TCE uptake that was not released upon lowering the pressure back to atmospheric conditions. This showed that the increase in pressure was able to rapidly induce the formation of a desorption-resistant fraction that previous investigations have shown requires months to develop at atmospheric pressure. Grand Canonical Monte Carlo (GCMC) modeling was then used to elucidate the nature of water and TCE behavior within silica micropores. The GCMC modeling showed that molecular scale packing restrictions resulted in pore fluid densities that ranged from 0.28 to 0.78 of those in the bulk solution. The modeling also showed that TCE was able to displace water from hydrophilic mineral pores due to molecular scale packing restrictions. Exothermic isosteric heats for TCE adsorption up to -27 kJ/mol were observed and were greatest in pores of 7 and 8 A. This indicated that TCE adsorption was energetically most favorable in pores that were minimally large enough to accommodate a TCE molecule. The pressure-induced uptake appeared to result primarily from an increase in the packing density in the smallest pores. Ab initio calculations showed that small distortions of a TCE molecule from its low energy conformation require high activation energies. Results from this study indicate that activated adsorption requiring bond angle distortions in the adsorbate may be responsible forthe slow attainment of adsorptive equilibrium of HOCs on microporous solids. Likewise, activated desorption from molecular-sized adsorption sites may contribute to the slow release of HOCs from aquifer sediments.

Absorption↗

PubMed2002

An fMRI study on the time-limited role of the medial temporal lobe in long-term topographical autobiographic memory.

The time-limited role of the medial temporal lobe (MTL) in human long-term memory is well known. However, there is still no direct neuroimaging evidence to confirm it. In this fMRI study, nine subjects were scanned while asked to recall the places they visited more than seven years ago (remote memories); and the places they visited recently (recent memories). We observed robust and dominant MTL activity peaking in the left parahippocampal gyrus when recent memories were contrasted with remote memories. This result provided direct evidence for the time-limited role of the MTL in long-term topographical autobiographic memory. Further analysis revealed that this MTL activity was not due to the fact that the retrieval of recent memories was accompanied by more details. When detailed recent memories were contrasted with detailed remote memories, there was still MTL activity peaking in the left parahippocampal gyrus. The effects of details in remote memories are also discussed.

Adult↗

PubMed2002

Role of medial temporal lobe in extensive retrieval of task-related knowledge.

The role of medial temporal lobe (MTL) in deep semantic processing was examined in a triple semantic judgment task in which subjects were asked to decide which one of the two bottom words was more semantically fit to the top word. By changing the number of bottom words that are semantically related to the top word, we can disassociate effects of reactivating the "old" semantic associations and effects of establishing "new" semantic associations on the MTL. The results of event-related fMRI analysis indicated that MTL was more activated in the retrieval of old semantic associations than in the establishment of new semantic associations. The function of MTL in this semantic judgment task was explained as subserving the process of extensive retrieval of task-related knowledge.

Adult↗

PubMed2002

The origin and genetic diversity of Chinese native chicken breeds.

The first 539 bases of mitochondrial DNA D-loop region of six Chinese native chicken breeds (Gallus gallus domesticus) were sequenced and compared to those of the red junglefowl (Gallus gallus), the gray junglefowl (Gallus sonneratii), the green junglefowl (Gallus varius) and Lafayette's junglefowl (Gallus lafayettei) reported in GenBank, and the phylogenetic trees for the chickens were constructed based on the D-loop sequences. The results showed that the four species of the genus Gallus had great differences among each other the G. g. domesticus was closest to the red junglefowl in Thailand and its adjacent regions, suggesting the Chinese domestic fowl probably originatedfrom the red junglefowl in these regions. The two subspecies of Thailand, G. g. gallus and G. g. spadiceus, should belong to one subspecies because of their resemblance. In the case of native breeds, there existed a great difference between the egg breeds and general purpose breeds, which suggested different maternal origins of the two types.

Animals↗

PubMed2002

Five-week, low-glycemic index diet decreases total fat mass and improves plasma lipid profile in moderately overweight nondiabetic men.

OBJECTIVE: To evaluate whether a 5-week low-glycemic index (LGI) diet versus a high-glycemic index (HGI) diet can modify glucose and lipid metabolism as well as total fat mass in nondiabetic men. RESEARCH DESIGN AND METHODS: In this study, 11 healthy men were randomly allocated to 5 weeks of an LGI or HGI diet separated by a 5-week washout interval in a crossover design. RESULTS: The LGI diet resulted in lower postprandial plasma glucose and insulin profiles and areas under the curve (AUCs) than the HGI diet. A 5-week period of the LGI diet lowered plasma triacylglycerol excursion after lunch (AUC, P < 0.05 LGI vs. HGI). These modifications were associated with a decrease in the total fat mass by approximately 700 g (P < 0.05) and a tendency to increase lean body mass (P < 0.07) without any change in body weight. This decrease in fat mass was accompanied by a decrease in leptin, lipoprotein lipase, and hormone-sensitive lipase RNAm quantities in the subcutaneous abdominal adipose tissue (P < 0.05). CONCLUSIONS: We concluded that 5 weeks of an LGI diet ameliorates some plasma lipid parameters, decreases total fat mass, and tends to increase lean body mass without changing body weight. These changes were accompanied by a decrease in the expression of some genes implicated in lipid metabolism. Such a diet could be of benefit to healthy, slightly overweight subjects and might play a role in the prevention of metabolic diseases and their cardiovascular complications.

Adult↗