Biomedical subjects

Yong Lu

Publications and source records attributed to Yong Lu.

At least 37 records · Page 2Linked to original sources

PubMed2005

[Observation on therapeutic effect of acupuncture combined with drug for treatment of intestinal metaplasia of chronic atrophic gastritis].

OBJECTIVE: To search for an effective method for treatment of intestinal metaplasia of gastric mucosa in the patient of chronic atrophic gastritis. METHODS: Fifty-one cases of chronic atrophic gastritis with intestinal metaplasia were randomly divided into a treatment group (n = 26) and a control group (n = 25). The treatment group were treated with acupuncture at main acupoints: Zhongwan (CV 12), Zusanli (ST 36), Neiguan (PC 6), Gongsun (SP 4), and oral administration of modified Sijunzi Decoction, and the control group with the modified Sijunzi Decoction. After treatment for 3 months, clinical symptoms, results of gastroscopy and pathological changes of gastric mucosa were compared between the two groups. RESULTS: There was no significant difference in improvement of the clinical symptoms between the two groups (P > 0.05); the total effective rate of 88.46% for gastroscopy in the treatment group was better than 64.00% in the control group (P < 0.05); and the total effective rate of 84.62% for pathological improvement of intestinal metaplasia in the treatment group was superior to 64.00% in the control group (P < 0.05). CONCLUSION: Acupuncture combined with Chinese drug is a better therapy for intestinal metaplasia of gastric mucosa in the patient of chronic atrophic gastritis.

Acupuncture Points↗

PubMed2004

GABA(B) receptor activation modulates GABA(A) receptor-mediated inhibition in chicken nucleus magnocellularis neurons.

Neurons of nucleus magnocellularis (NM), a division of avian cochlear nucleus that performs precise temporal encoding, receive glutamatergic excitatory input solely from the eighth nerve and GABAergic inhibitory input primarily from the ipsilateral superior olivary nucleus. GABA activates both ligand-gated Cl- channels [GABA(A) receptors (GABA(A)Rs)] and G protein-coupled receptors (GABA(B) receptors). The net effect of GABA(A)R-mediated input to NM is inhibitory, although depolarizing. Several studies have shown that this shunting, inhibitory GABAergic input can evoke action potentials in postsynaptic NM neurons, which could interfere with their temporal encoding. While this GABA-mediated firing is limited by a low-voltage-activated K+ conductance, we have found evidence for a second mechanism. We investigated modulation of GABA(A)R-mediated responses by GABA(B)Rs using whole cell recording techniques. Bath-applied baclofen, a GABA(B)R agonist, produced dose-dependent suppression of evoked inhibitory postsynaptic currents (eIPSCs). This suppression was blocked by CGP52432, a potent and selective GABA(B)R antagonist. Baclofen reduced the frequency but not the amplitude of miniature IPSCs (mIPSCs) and did not affect postsynaptic currents elicited by puff application of a specific GABA(A)R agonist muscimol, suggesting a presynaptic mechanism for the GABA(B)R-mediated modulation. Firing of NM neurons by synaptic stimulation of GABAergic inputs to NM was eliminated by baclofen. However, endogenous GABA(B)R activity in the presynaptic inhibitory terminals was not observed. We propose that presynaptic GABA(B)Rs function as autoreceptors, regulating synaptic strength of GABA(A)R-mediated inhibition, and prevent NM neurons from generating firing during activation of the inhibitory inputs.

Analysis of Variance↗

PubMed2004

Activation of metabotropic glutamate receptors inhibits high-voltage-gated calcium channel currents of chicken nucleus magnocellularis neurons.

Using whole cell patch-clamp recordings, we pharmacologically characterized the voltage-gated Ca2+ channel (VGCC) currents of chicken nucleus magnocellularis (NM) neurons using barium as the charge carrier. NM neurons possessed both low- and high-voltage-activated Ca2+ channel currents (HVA I(Ba2+)). The N-type channel blocker (omega-conotoxin-GVIA) inhibited more than half of the total HVA I(Ba2+), whereas blockers of L- and P/Q-type channels each inhibited a small fraction of the current. Metabotropic glutamate receptor (mGluR)-mediated modulation of the HVA I(Ba2+) was examined by bath application of glutamate (100 microM), which inhibited the HVA I(Ba2+) by an average of 16%. The inhibitory effect was dose dependent and was partially blocked by omega-conotoxin-GVIA, indicating that mGluRs modulate N and other type HVA I(Ba2+). The nonspecific mGluR agonist, (1S,3R)-1-aminocyclopentane-1,3-dicarbosylic acid (1S,3R-ACPD), mimicked the inhibitory effect of glutamate on HVA I(Ba2+). Group I-III mGluR agonists showed inhibition of the HVA current with the most potent being the group III agonist L(+)-2-amino-4-phosphonobutyric acid. 1S,3R-ACPD (200 microM) had no effect on K+ or Na+ currents. The firing properties of NM neurons were also not altered by 1S,3R-ACPD. We propose that the inhibition of VGCC currents by mGluRs limits depolarization-induced Ca2+ entry into these highly active NM neurons and regulates their Ca2+ homeostasis.

Animals↗

PubMed2004

Activity-dependent regulation of the potassium channel subunits Kv1.1 and Kv3.1.

Afferent activity, especially in young animals, can have profound influences on postsynaptic neuronal structure, function and metabolic processes. Most studies evaluating activity regulation of cellular components have examined the expression of ubiquitous cellular proteins as opposed to molecules that are specialized in the neurons of interest. Here we consider the regulation of two proteins (voltage-gated potassium channel subunits Kv1.1 and Kv3.1) that auditory brainstem neurons in birds and mammals express at uniquely high levels. Unilateral removal of the avian cochlea leads to rapid and dramatic reduction in the expression of both proteins in the nucleus magnocellularis (NM; a division of the avian cochlear nucleus) neurons as detected by immunocytochemistry. Uniform downregulation of Kv1.1 was reliable by 3 hours after cochlea removal, was sustained through 96 hours, and returned to control levels in the surviving neurons by 2 weeks. The activity-dependent changes in Kv3.1 appear to be bimodal and are more transient, being observed at 3 hours after cochlea removal and recovering to control levels within 24 hours. We also explored the functional properties of Kv1.1 in NM neurons deprived of auditory input for 24 hours by whole-cell recordings. Low-threshold potassium currents in deprived NM neurons were not significantly different from control neurons in their amplitude or sensitivity to dendrotoxin-I, a selective K+ channel antagonist. We conclude that the highly specialized abundant expression of Kv1.1 and 3.1 channel subunits is not permanently regulated by synaptic activity and that changes in overall protein levels do not predict membrane pools.

Animals↗

PubMed2004

Adaptive swarm-based routing in communication networks.

Swarm intelligence inspired by the social behavior of ants boasts a number of attractive features, including adaptation, robustness and distributed, decentralized nature, which are well suited for routing in modern communication networks. This paper describes an adaptive swarm-based routing algorithm that increases convergence speed, reduces routing instabilities and oscillations by using a novel variation of reinforcement learning and a technique called momentum. Experiment on the dynamic network showed that adaptive swarm-based routing learns the optimum routing in terms of convergence speed and average packet latency.

Adaptation, Physiological↗

PubMed2004

[The influence to maxillary growth by exposed bone wound in hard palate of rat].

OBJECTIVE: To confirm if denuded bone on lateral aspects of the hard palate of surgical repairs of the cleft palate is the main reason of causing disturbance of facial growth and to investigate the mechanism. METHODS: 48 SD rats were employed in the study. Among them 40 animals were divided into normal control and experimental group randomly. Normal control was not operated. Hard palate mucoperiosteum on the left side in experimental group were excised. Left hard palate mucoperiosteum in another 8 female three-week-old SD rats were excised with same method and were sacrificed at 2nd, 5th, 8th, and 12th day, respectively. The 8 rats were used for histological research. RESULTS: The width of all left sides hard palates in experimental group was significantly narrower than right side, and demonstrated statistical difference. Chronic osteomyelitis on the denuded hard palate was observed. CONCLUSION: The denuded bone wound might be a principal factor for the following maxillary growth deformity in cleft palate patients who received palatoplasty in childhood. The mechanism of causing the deformity might be wound and scar contraction, decreased blood flow and nutrition plus chronic osteomyelitis.

Animals↗

PubMed2004

[Epstein-Barr virus infection in lymphoepithelial carcinoma of salivary glands in Sichuan Chinese].

OBJECTIVE: To determine the prevalence of Epstein-Barr virus (EBV) infection in lymphoepithelial carcinoma (LEC) of salivary glands in Sichuan Chinese and discuss the role of EBV infection in pathogenesis of LEC. METHODS: Paraffin sections of 16 cases of LEC and 4 cases of benign lymphoepithelial lesion (BLEL) of salivary glands, 4 cases of non-specific chronic sialadenitis were examined by in situ hybridization for EBV encoded small RNA-1 (EBER-1) using 30-base synthesized oligonucleotide probe. RESULTS: Strong signals for EBER-1 were obtained in most of tumor cell nuclei in all the specimens of LEC (16/16); in contrast, there were no significant signals observed in the examination of 4 cases of BLEL and 4 cases of non-specific chronic sialadenitis. CONCLUSION: The results indicate that EBV plays an important role in the pathogenesis of LEC of salivary glands in Sichuan Chinese.

Adult↗

PubMed2004

[Epstein-Barr virus infection in benign lymphoepithelial lesions with malignant transformation of salivary glands].

OBJECTIVE: To examine the role of Epstein-Barr virus (EBV) infection in benign lymphoepithelial lesions with malignant transformation of salivary glands. METHODS: 2 cases benign lymphoepithelial lesions with focal malignant transformation (BLEL-FMT), 14 cases of malignant lymphoepithelial lesion (MLEL) and 4 cases of benign lymphoepithelial lesion (BLEL) of salivary glands, 4 cases of nonspecific chronic sialadenitis were examined. Sections were cut from the paraffin blocks and performed in situ hybridization (ISH) for EBV encoded small RNA-1 (EBER-1) using 30-base synthesized oligonucleotide probe and polymerase chain reaction (PCR) for BamHI-W regein of EBV DNA (123 bp). RESULTS: In ISH, strong signals for EBER-1 were obtained in most of epithelial cell nuclei in examined specimens of BLEL-FMT, no matter in benign or malignant areas and in all specimens of MLEL (14/14), PCR demonstrated a DNA fragment of 123 kbp in 2 cases of BLEL-FMT and 12 cases of MLEL (12/14). In contrast, there were no significant ISH/PCR signals in examined BLEL and nonspecific chronic sialadenitis. CONCLUSIONS: A few cases of MLEL may arise from BLEL and EBV may plays an important role in the pathogenesis of BLEL-FMT of salivary glands.

Epstein-Barr Virus Infections↗

PubMed2003

Trophoblast expression of fms-like tyrosine kinase 1 is not required for the establishment of the maternal-fetal interface in the mouse placenta.

Fms-like tyrosine kinase 1 (Flt1)/vascular endothelial growth factor (VEGF) receptor 1, a receptor for VEGF-A and placental growth factor, is expressed in the spongiotrophoblast layer that segregates the maternal and fetal vasculature in the mouse placenta. A soluble form of Flt1 (sFlt1) produced in the mouse and human placenta can also be detected in the maternal blood. Levels of maternal sFlt1 are elevated in preeclampsia, suggesting that placental sFlt1 plays roles in regulating the maternal vasculature during pregnancy. However, it remains to be determined whether placental Flt1/sFlt1 serves as a regulator of VEGF-A activity in the placenta per se. Here, we investigated the placental development in Flt1-deficient mice. Flt1 is expressed in a subpopulation of ectoplacental cone cells and later marks the spongiotrophoblast cells, peri/endovascular trophoblast cells, and trophoblast glycogen cells. The labyrinth of Flt1lacZ/lacZ placentae lacked the fetal capillary network because of a defect in allantoic mesoderm invasion. To address whether the absence of Flt1 in the trophoblast alone affects placental development, we investigated chimeric placentae comprised of Flt1lacZ/lacZ trophoblast and Flt1+/+ mesoderm, generated by tetraploid aggregation. Fetal growth was supported normally, and no defect in the formation of placental circulation into the maternal spiral artery or invasion of peri/endovascular trophoblast was detected. These findings indicate that trophoblast-derived Flt1/sFlt1 is dispensable for the initial establishment of the maternal-fetal interface in the mouse placenta. Targeting maternal sFlt1 levels for treatment of preeclampsia may thus be possible without affecting the proper formation of the placenta.

Animals↗

PubMed2003

A novel mutation of keratin 9 in epidermolytic palmoplantar keratoderma combined with knuckle pads.

Epidermolytic palmoplantar keratoderma (EPPK) is an autosomal dominantly inherited disease. We studied a family from Shandong, China, having patients suffering from EPPK with a unique symptom-knuckle pads. We noticed that both the hyperkeratosis and knuckle pads in the Chinese family were friction-related. Candidate gene analysis was carried out using linkage analysis and direct sequencing. A novel L160F mutation in keratin 9 was found, and its effects on the secondary structure of keratin 9 were studied. We predict that the L160F mutation is also responsible for the knuckle pads in the family. Our study provides a new clue for the study of the function of keratin 9.

DNA Mutational Analysis↗

PubMed2003

Macromolecular effect: synthesis of a ferrocenylmethylphosphine-containing polymer as highly efficient ligands for room-temperature palladium(0)-catalyzed Suzuki cross-coupling reactions of aryl chlorides.

The design and synthesis of a ferrocenylmethylphosphine-containing polymer and its application as efficient ligands for the room-temperature Pd(0)-catalyzed cross-coupling reaction of aryl chlorides with arylboronic acids, for which corresponding monomeric monophosphines are totally inactive, are described. Our work demonstrated that rather small monophosphine moieties such as RPPh2 can be used as highly efficient ligands when appropriately incorporated into a rigid and sterically regular polymer network and using monophosphine-containing polymers as ligands is a feasible approach to access highly active (monophosphine)-palladium(0) complexes. The macromolecular approach described here may open a new avenue to other coordinatively unsaturated (monoligand)-transition metal complexes which are potentially useful in organic synthesis.

Journal Article↗

PubMed2003

Direct synthesis of ferrocenylmethylphosphines from ferrocenylmethyl alcohols and their application as ligands for room temperature Pd(0)-catalyzed Suzuki cross-couplings of aryl bromides.

[reaction: see text] The direct, high-yield conversion of readily available ferrocenylmethyl alcohols to ferrocenylmethylphosphines and the application of ferrocenylmethylphosphines as efficient ligands for room temperature Suzuki cross-coupling reaction of aryl bromides with phenylboronic acid are reported. The procedure of directly converting ferrocenylmethyl alcohols to ferrocenylmethylphosphines described here should find applications in the synthesis of many metallocenylmethylphosphines including optically active ones.

Journal Article↗

PubMed2003

Binaural interaction in the inferior colliculus of the big brown bat, Eptesicus fuscus.

Binaural interaction plays an important role in shaping response properties of central auditory neurons. Using single unit recording and iontophoresis, we examined frequency tuning curves (FTCs), interaural intensity difference (IID) curves, and rate-intensity functions of inferior collicular (IC) neurons of the big brown bat, Eptesicus fuscus, under closed system or free field stimulation conditions. We isolated 46 EI (excitation-inhibition), 24 EO (monaural excitation) and 6 EE (excitation-excitation) neurons. Inhibitory FTCs of EI neurons plotted under ipsilateral sound stimulation fell within (n=10, 22%), partly overlapped (n=26, 56%), or almost entirely encompassed (n=10, 22%) excitatory FTCs plotted by contralateral sound stimulation. The discharge rate of EI neurons was a sigmoid function of IID. The peak discharge rate occurred at IIDs at which contralateral sound stimulation was stronger than ipsilateral sound stimulation. Application of bicuculline, an antagonist for gamma-aminobutyric acid A receptors, raised the IID curves and broadened the excitatory FTCs but partly or completely abolished the ipsilateral inhibitory FTCs. For EE neurons, excitatory FTCs and rate-intensity functions plotted by contralateral sound stimulation were always broader and higher than those plotted by ipsilateral sound stimulation. The sharpness of FTCs of EI neurons was significantly greater at ipsilateral 30 degrees than at 30 degrees contralateral. This direction-dependent frequency tuning was effectively abolished by occlusion of the ipsilateral ear. Possible mechanisms underlying these observations are discussed.

Acoustic Stimulation↗

PubMed2003

Embryonic stem cells generated by nuclear transfer of human somatic nuclei into rabbit oocytes.

To solve the problem of immune incompatibility, nuclear transplantation has been envisaged as a means to produce cells or tissues for human autologous transplantation. Here we have derived embryonic stem cells by the transfer of human somatic nuclei into rabbit oocytes. The number of blastocysts that developed from the fused nuclear transfer was comparable among nuclear donors at ages of 5, 42, 52 and 60 years, and nuclear transfer (NT) embryonic stem cells (ntES cells) were subsequently derived from each of the four age groups. These results suggest that human somatic nuclei can form ntES cells independent of the age of the donor. The derived ntES cells are human based on karyotype, isogenicity, in situ hybridization, PCR and immunocytochemistry with probes that distinguish between the various species. The ntES cells maintain the capability of sustained growth in an undifferentiated state, and form embryoid bodies, which, on further induction, give rise to cell types such as neuron and muscle, as well as mixed cell populations that express markers representative of all three germ layers. Thus, ntES cells derived from human somatic cells by NT to rabbit eggs retain phenotypes similar to those of conventional human ES cells, including the ability to undergo multilineage cellular differentiation.

Adult↗

PubMed2003

Inferences on the common mean of several normal populations based on the generalized variable method.

This article presents procedures for hypothesis testing and interval estimation of the common mean of several normal populations. The methods are based on the concepts of generalized p-value and generalized confidence limit. The merits of the proposed methods are evaluated numerically and compared with those of the existing methods. Numerical studies show that the new procedures are accurate and perform better than the existing methods when the sample sizes are moderate and the number of populations is four or less. If the number of populations is five or more, then the generalized variable method performs much better than the existing methods regardless of the sample sizes. The generalized variable method and other existing methods are illustrated using two examples.

Albumins↗

PubMed2003

[Gene mapping of a nonsyndromic hearing impairmint family].

OBJECTIVE: To map the gene responsible for nonsyndromic hearing impairment in a consanguineous family. METHODS: Firstly, X chromosome scanning was used to exclude X chromosome. Secondly, candidate gene analyzing and genome scanning were performed by homozygosity mapping. Then, additional markers flanking the tightly linked marker were tested to confirm linkage and decide the candidate region. RESULTS: The nonsyndromic hearing impairment of this family was autosomal recessive. Twenty-five known genes were excluded. Autosomal genome scanning indicated that D17S1293 was tightly linked with disease gene. And further study mapped the disease gene to a 5.07 cM interval bounded by D17S1850 and D17S1818. CONCLUSION: The disease gene of the family is mapped to a 5.07 cM interval between D17S1850 and D17S1818, which is a new locus of autosomal recessive nonsyndromic hearing impairment.

Chromosome Mapping↗

PubMed2003

[Effects of combined surfactant and inhaled nitric oxide in ventilated rabbits with meconium aspiration-induced acute lung injury].

OBJECTIVE: To evaluate dose response of inhaled nitric oxide (iNO) for surfactant-treated rabbits with meconium aspiration-induced acute lung injury (ALI) and hypoxemic respiratory failure (HRF), and variation of measured iNO by continuous NO delivery in pressure support ventilation (PSV). METHODS: Adult rabbits (2.0 - 3.5 kg, n = 33) were randomized to receive intratracheal meconium instillation for 30 min and subjected to following treatment (n = 6 - 8). There were 4 groups: Control (C); NO, iNO at 1, 10, 20 and 40 x 10(-6) each for 60 min at 30 min interval of disconnection; Surf, intratracheal instillation of porcine lung surfactant phospholipids (100 mg/kg); SNO, both iNO and surfactant as in the NO and Surf groups; and a normal group (N), which did not undergo meconium aspiration but received sham deliveries of normal saline. All the animals were treated with PSV for 6 h. iNO levels at different input and sampling sites in the NO and SNO groups were detected by on-line chemiluminescent technique. The blood gas and lung mechanics were measured during the experiments every 2 h. RESULTS: (1) Meconium aspiration induced ALI and severe HRF (PaO(2)/FiO(2) < 200 mmHg) and depressed dynamic compliance of respiratory system (Cdyn) and airway resistance (Raw). In both Surf and NO groups modestly improved oxygenation was observed. In the SNO, values for PaO(2)/FiO(2) were improved from (185 +/- 39) mmHg at baseline to (301 +/- 123) mmHg at 6 h, while moderate or transient improvement was observed in both Surf and NO groups. Cdyn and Raw were only improved for short time in the Surf, NO and SNO groups. iNO had a mild response at 1 x 10(-6) to good response at 10 and 20 x 10(-6), but no further improvement occurred at 40 x 10(-6). The response of iNO in NO group was relatively transient compared to the SNO group. (2) When iNO was connected to the ventilator circuit, the connected site should be placed before humidifier to minimize fluctuation of iNO concentration, and sampling site for iNO monitoring should be placed adequately to eliminate artifact. CONCLUSIONS: iNO synergistically improved surfactant effects on oxygenation and lung mechanics. Continuous supply of iNO with non-continuous flow ventilator provided stable NO within accepted target range with least variation.

Administration, Inhalation↗

PubMed2002

Interactions between trophoblast cells and the maternal and fetal circulation in the mouse placenta.

Mammalian embryos have an intimate relationship with their mothers, particularly with the placental vasculature from which embryos obtain nutrients essential for growth. It is an interesting vascular bed because maternal vessel number and diameter change dramatically during gestation and, in rodents and primates, the terminal blood space becomes lined by placental trophoblast cells rather than endothelial cells. Molecular genetic studies in mice aimed at identifying potential regulators of these processes have been hampered by lack of understanding of the anatomy of the vascular spaces in the placenta and the general nature of maternal-fetal vascular interactions. To address this problem, we examined the anatomy of the mouse placenta by preparing plastic vascular casts and serial histological sections of implantation sites from embryonic day (E) 10.5 to term. We found that each radial artery carrying maternal blood into the uterus branched into 5-10 dilated spiral arteries located within the metrial triangle, populated by uterine natural killer (uNK) cells, and the decidua basalis. The endothelial-lined spiral arteries converged together at the trophoblast giant cell layer and emptied into a few straight, trophoblast-lined "canals" that carried maternal blood to the base of the placenta. Maternal blood then percolated back through the intervillous space of the labyrinth toward the maternal side of the placenta in a direction that is countercurrent to the direction of the fetal capillary blood flow. Trophoblast cells were found invading the uterus in two patterns. Large cells that expressed the trophoblast giant cell-specific gene Plf (encoding Proliferin) invaded during the early postimplantation period in a pattern tightly associated with spiral arteries. These peri/endovascular trophoblast were detected only approximately 150-300 microm upstream of the main giant cell layer. A second type of widespread interstitial invasion in the decidua basalis by glycogen trophoblast cells was detected after E12.5. These cells did not express Plf, but rather expressed the spongiotrophoblast-specific gene Tpbp. Dilation of the spiral arteries was obvious between E10.5 and E14.5 and was associated with a lack of elastic lamina and smooth muscle cells. These features were apparent even in the metrial triangle, a site far away from the invading trophoblast cells. By contrast, the transition from endothelium-lined artery to trophoblast-lined (hemochorial) blood space was associated with trophoblast giant cells. Moreover, the shaping of the maternal blood spaces within the labyrinth was dependent on chorioallantoic morphogenesis and therefore disrupted in Gcm1 mutants. These studies provide important insights into how the fetoplacental unit interacts with the maternal intrauterine vascular system during pregnancy in mice.

Animals↗