Room-temperature hybridization of target DNA with microarrays in concentrated solutions of guanidine thiocyanate.
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Biotechnology↗
Biomedical subjects
Y H Liu
Publications and source records attributed to Y H Liu.
YY1 activates Msx2 gene independent of bone morphogenetic protein signaling.
Msx2 is a homeobox gene expressed in multiple embryonic tissues which functions as a key mediator of numerous developmental processes. YY1 is a bi-functional zinc finger protein that serves as a repressor or activator to a variety of promoters. The role of YY1 during embryogenesis remains unknown. In this study, we report that Msx2 is regulated by YY1 through protein-DNA interactions. During embryogenesis, the expression pattern of YY1 was observed to overlap in part with that of Msx2. Most notably, during first branchial arch and limb development, both YY1 and Msx2 were highly expressed, and their patterns were complementary. To test the hypothesis that YY1 regulates Msx2 gene expression, P19 embryonal cells were used in a number of expression and binding assays. We discovered that, in these cells, YY1 activated endogenous Msx2 gene expression as well as Msx2 promoter-luciferase fusion gene activity. These biological activities were dependent on both the DNA binding and activation domains of YY1. In addition, YY1 bound specifically to three YY1 binding sites on the proximal promoter of Msx2 that accounted for this transactivation. Mutations introduced to these sites reduced the level of YY1 transactivation. As bone morphogenetic protein type 4 (BMP4) regulates Msx2 expression in embryonic tissues and in P19 cells, we further tested whether YY1 is the mediator of this BMP4 activity. BMP4 did not induce the expression of YY1 in early mouse mandibular explants, nor in P19 cells, suggesting that YY1 is not a required mediator of the BMP4 pathway in these tissues at this developmental stage. Taken together, these findings suggest that YY1 functions as an activator for the Msx2 gene, and that this regulation, which is independent of the BMP4 pathway, may be required during early mouse craniofacial and limb morphogenesis.
Animals↗
Application of narrow band laser ultrasonics to the nondestructive evaluation of thin bonding layers.
In this paper, a modified laser induced grating technique (LIG) has been utilized to generate narrow band surface waves in an epoxy-bonded copper-aluminum layered structure. A high performance optical interferometer system was utilized to detect the laser-generated surface waves. The dispersion of surface wave in an epoxy-bonded copper-aluminum specimen was measured and compared with the theoretical solution. An inverse algorithm based on the simplex method was then introduced to determine the bonding thickness as well as the elastic properties of the bonding layer. The inversion results demonstrated that the thickness in the microm range or the elastic properties of the bonding layer could be successfully determined.
Journal Article↗
[Establishment of rabbit model for peritoneal dialysis related peritonits].
OBJECTIVE: To establish a rabbit model corresponding with clinical characteristics of peritoneal dialysis related peritonitis. METHODS: Twelve New Zealand rabbits were randomly divided into peritonitis group and control group. They were infused standard living Staphylococcus aureus 3 x 10(9) colony forming unit (cfu) (peritonitis group) or 0.9% NaCl 1 ml (control group). After 48 hours, Laboratory rabbits in acute uremic model underwent regular dialysis for 6 hours. At different points of time, the concentration of glucose in dialysate and the dialysate/plasma (D/P) ratio of the concentration creatinine (Cr), total protein(TP), album(Alb) and IgG, the counts of leukocyte in dialysate and water ultrafiltrate were determined. RESULTS: D/D0 were significantly lower in the peritonitis group than that in the control group (P < 0.05). The counts of leukocyte and D/P ratio of Cr, TP, Alb and IgG were significantly increased in the peritonitis group (all P < 0.05). The drained volume was lower in the peritonitis group than that in the control group (but P > 0.05). CONCLUSION: In the rabbit model infused intraperoneally staphylococcus aureus, (1) transport peritoneum of low and large molecular weight solutes is increased, (2) the volume of ultrafiltrate is decreased, (3) the counts of leukocyte in dialysate is increased. These change in this model is basic all correspond with the clinical feature of patients of peritoneal dialysis related peritonitis. So this rabbit model of peritoneal dialysis related peritonitis is a successful experimental infection model.
Animals↗
Assembly of a robust, thermally stable porous cobalt(II) nicotinate framework based on a dicobalt carboxylate unit.
A series of robust, thermally stable open-framework cobalt nicotinate compounds, Co(2)(H(2)O)[C(6)H(4)O(2)N](4).0.5CH(3)CH(2)OH.0.5H(2)O (1), Co(2)(H(2)O)[C(6)H(4)O(2)N](4) (2), and Co(2)(H(2)O)[C(6)H(4)O(2)N](4).C(6)H(5)CH(2)OH (3), based on rigid dimetallic carboxylate clusters as the basic building unit have been prepared. Single-crystal X-ray crystallographic analyses of 1 and 3 reveal the host framework possessing an effective channel area with the dimensions of 10.8 x 4.5 A. These channels can accommodate guest molecules of various sizes and shapes such as ethanol, water, and benzyl alcohol. Thermogravimetric analysis shows a two-step weight loss corresponding to the loss of guest molecules followed by the loss of coordinated water. The host framework is thermally stable up to 295 degrees C. The cobalt nicotinate host remains intact, even upon the removal of the guest to form compound 2 as revealed by single-crystal X-ray diffraction analysis. Crystal data for 1: Co(2)(H(2)O)[C(6)H(4)O(2)N)](4).0.5CH(3)CH(2)OH.0.5H(2)O, fw = 656.33, triclinic, space group P(-)1, a = 10.5407(2) A, b = 11.8266(3) A, c = 14.1122(2) A, alpha = 106.878(4) degrees, beta = 102.411(2) degrees, gamma = 111.011(3) degrees, V = 1467.9(5) A(3), Z = 2. Crystal data for 2: Co(2)(H(2)O)[C(6)H(4)O(2)N](4), fw = 624.28, triclinic, space group P(-)1, a = 10.507(3) A, b = 11.824(2) A, c = 14.113(3) A, alpha = 107.06(2) degrees, beta = 102.39(2) degrees, gamma = 111.105(16) degrees, V = 1459.5(6) A(3), Z = 2. Crystal data for 3: Co(2)(H(2)O)[C(6)H(4)O(2)N](4).C(6)H(5)CH(2)OH, fw = 732.42, triclinic, space group P(-)1, a = 10.6671(6) A, b = 12.0063(7) A, c = 14.0658(8) A, alpha = 106.7180(10) degrees, beta = 102.2790(10) degrees, gamma = 111.1900(10) degrees, V = 1504.1(6) A(3), Z = 2. The magnetic exchange coupling between the dicobalt centers for compounds 1 and 3 are analyzed on the basis of both the Curie-Weiss expression and a binuclear magnetic model. The negative values of the magnetic exchange coupling constant indicate the antiferromagnetic nature within the cobalt dimer.
Journal Article↗
Direct layer-by-layer freezing of a smectic liquid-crystal surface into the crystalline phase.
Electron diffraction and optical reflectivity have provided the direct confirmation of the existence of layer-by-layer surface transitions from the smectic-A immediately to the crystal-B phase in a liquid-crystal material, without going through an intermediate hexatic phase. The molecular interactions are found to be through retarded van der Waals forces. Our results suggest that a smectic-A film can transform into a crystal-B through three possible scenarios.
Journal Article↗
Colonoscopy in mice.
INTRODUCTION: Current investigational models of murine colitis and colon cancer necessitate sacrifice of animals in order to obtain colonic tissue. The purpose of this study was to develop a safe method of murine colonoscopy that would allow serial evaluation and mucosal biopsies of the same animal. METHODS: Nine mice (two C3H, two C57/BL6, and five IL-10 deficient) were studied a total of four times each over 4 weeks. Three mice [APC (Min +/-)] were examined three times each. Mice were gavaged with 1 cc of a polyethylene glycol solution on the day prior to colonoscopy. Solid chow was withheld and the mice were maintained on Pedialyte. Mice were anesthetized with ketamine and xylazine. A flexible pediatric cystoscope (2.1-mm diameter) with a single biopsy channel was introduced per anum, and the colon was gently insufflated with air to a mean pressure of less than 5 mmHg. Saline irrigation was used when necessary. A single biopsy was obtained from the rectosigmoid colon during each examination. RESULTS: A total of 46 examinations were carried out. One mouse died after being anesthesized for the fourth examination, and two mice [one IL-10 knockout and one APC (Min+/-)] died one day after the 3rd examination. No other complications were noted. The average length of insertion was 3 cm. Transillumination allowed for localization of the endoscope tip. Biopsies, although quite small, were sufficient for pathologic evaluation and diagnosis. CONCLUSIONS: Murine colonoscopy is a safe and feasible technique. It permits consecutive visual and histopathological examinations, and it allows the investigator to monitor the response of the murine colon to experimental interventions.
Animals↗
Empty capsids in column-purified recombinant adenovirus preparations.
Empty capsids from adenovirus, that is, virus particles lacking DNA, are well documented in the published literature. They can be separated from complete virus by CsCl density gradient centrifugation. Here we characterize the presence of empty capsids in recombinant adenovirus preparations purified by column chromatography. The initial purified recombinant adenovirus containing the p53 tumor suppressor gene was produced from 293 cells grown on microcarriers and purified by passage through DEAE-Fractogel and gel-filtration chromatography. Further sequential purification of the column-purified virus by CsCl and glycerol density gradient centrifugations yielded isolated complete virus and empty capsids. The empty capsids were essentially noninfectious and free of DNA. Analysis of empty capsids by SDS-PAGE or RP-HPLC showed the presence of only three major components: hexon, IIIa, and a 31K band. This last protein was identified as the precursor to protein VIII (pVIII) by mass spectrometric analysis. No pVIII was detected from the purified complete virus. Analysis by electron microscopy of the empty capsids showed particles with small defects. The amount of pVIII was used to determine the level of empty capsid contamination. First, the purified empty capsids were used to quantify the relation of pVIII to empty capsid particle concentration (as estimated by either light scattering or hexon content). They were then used as a standard to establish the empty capsid concentration of various recombinant adenovirus preparations. Preliminary research showed changes in empty capsid concentration with variations in the infection conditions. While virus purification on anion-exchange or gel-filtration chromatography has little effect on empty capsid contamination, other chromatographic steps can substantially reduce the final concentration of empty capsids in column-purified adenovirus preparations.
Adenoviridae↗
[Effect of peritonitis pathomorphology on rabbit model in peritoneal dialysis].
The study about peritonitis rabbit model is rarely, although peritonitis have been considered mainly complication in peritoneal dialysis. Twelve New Zealand rabbit were divided into peritonitis group and control group. The peritonitis group rabbit were injected with the dialysate containing alive staphylococcus aureus and the control ones with 0.9% saline into the peritoneum. The pathomorphology changes of the peritonitis were observed. The results showed (1) There was proliferation and swollen of mesothelial cells, vessel dilation and infiltration of inflammation cells in the peritoneum in the peritonitis group; and no such changes in the control group. (2) The D/D0 glucose concentration in the dialysate of peritonitis group was lower than that of the control ones at any point except the 0 min (P < 0.01). (3) The ratio of Cr concentration in the dialysate to Cr concentration in the plasma in the peritnitis group was significantly higher than that of the control group (P < 0.05). (4) The WBC count in the dialysate of peritonitis group was obviously higher than that of the control group all points except 0. These results implied that after injection of alive staphylococcus aureus to the peritoneal cavity of New Zealand rabbit for 48 hours, the pathomorphology change was similar with the characteristics of peritonitis complicated with peritoneal dialysis in patient.
Animals↗
Long-term effect of N-acetyl-seryl-aspartyl-lysyl-proline on left ventricular collagen deposition in rats with 2-kidney, 1-clip hypertension.
BACKGROUND: N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a natural inhibitor of pluripotent hematopoietic stem cell proliferation. Ac-SDKP plasma concentration is increased 5-fold after angiotensin-converting enzyme inhibition. Here we studied the effect of Ac-SDKP on monocyte/macrophage infiltration, fibroblast proliferation, and collagen deposition in the rat heart in renovascular hypertension. METHODS AND RESULTS: We investigated whether long-term Ac-SDKP administration would prevent left ventricular (LV) hypertrophy and interstitial collagen deposition in rats with 2-kidney, 1-clip (2K-1C) hypertension. Ac-SDKP (400 microgram. kg(-1). d(-1)) did not affect development of hypertension. Mean blood pressure was similar in rats with 2K-1C hypertension whether they were given vehicle or Ac-SDKP and was higher than in controls. Both LV weight and cardiomyocyte size were significantly increased in rats with 2K-1C hypertension compared with controls and were unaffected by Ac-SDKP. Proliferating cell nuclear antigen- and monocyte/macrophage-positive cells were increased in the LV of 2K-1C hypertensive rats; this increase was significantly blunted by Ac-SDKP (P<0.001). LV interstitial collagen fraction was also increased in 2K-1C hypertensive rats given vehicle (10.1+/-0.8%) compared with sham (5.3+/-0.1%, P<0.0001), and this increase was prevented by Ac-SDKP (5.4+/-0.4%, P<0.001). CONCLUSIONS: Ac-SDKP inhibited monocyte/macrophage infiltration, cell proliferation, and collagen deposition in the LV of hypertensive rats without affecting blood pressure or cardiac hypertrophy, suggesting that it may be partly responsible for the cardioprotective effect of angiotensin-converting enzyme inhibitors.
Animals↗
Diminished cardioprotective response to inhibition of angiotensin-converting enzyme and angiotensin II type 1 receptor in B(2) kinin receptor gene knockout mice.
Using B(2) kinin receptor gene knockout mice (B(2)(-/-)), we tested the hypothesis that (l) lack of B(2) receptors may affect blood pressure and cardiac function and aggravate cardiac remodeling after myocardial infarction (MI), and (2) kinins partially mediate the cardiac beneficial effect of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II type 1 receptor antagonists (AT(1)-ant), whereas lack of B(2) receptors may diminish this cardioprotective effect. Chronic heart failure (HF) was induced by MI, which was caused by coronary artery ligation in both B(2)(-/-) and 129/SvEvTac mice (wild-type control, B(2)(+/+)). An ACEi (ramipril, 2.5 mg/kg/d) or AT(1)-ant (L-158809, 3 mg/kg/d) was given 1 week after MI and was continued for 12 weeks. Left ventricular (LV) ejection fraction, cardiac output (CO), diastolic LV dimension (LVDd), and LV mass were evaluated by echocardiography. Myocyte cross-sectional area and interstitial collagen fraction were studied histopathologically. We found that basal blood pressure and cardiac function were similar in B(2)(+/+) and B(2)(-/-) mice. After MI, development of HF and remodeling were also similar between the 2 strains. The ACEi improved cardiac function and remodeling in both strains; however, its effects were attenuated in B(2)(-/-) mice (respective values for B(2)(+/+) versus B(2)(-/-) mice: overall increase in ejection fraction, 64+/-10% versus 21+/-5% [P<0.01]; increase in CO, 69+/-17% versus 23+/-9% [P<0.01]; overall decrease in LVDd, -24+/-3% versus -7+/-4% [P<0.01]; and decrease in LV mass, -38+/-3% versus -6+/-6% [P<0.01]). AT(1)-ant had a beneficial cardiac effect similar to that produced by ACEi, and this effect was also diminished in B(2)(-/-) mice (respective values for B(2)(+/+) versus B(2)(-/-) mice: overall increase in ejection fraction, 46+/-10% versus 25+/-9% [P<0.01]; increase in CO, 44+/-14% versus 15+/-5% [P<0.01]; overall decrease in LVDd, -14+/-4% versus -6+/-3% [P<0.01]; and decrease in LV mass, -33+/-4 versus -16+/-7% [P<0.01]). The effect of ACEi or AT(1)-ant on myocyte cross-sectional area was similar between strains; however, their effect on the interstitial collagen fraction was diminished in B(2)(-/-) mice. We concluded that (1) lack of B(2) kinin receptors does not affect cardiac phenotype or function, either under normal physiological conditions or during the development of HF; and (2) kinins acting via the B(2) receptor play an important role in the cardioprotective effect of ACEi and AT(1)-ant.
Angiotensin Receptor Antagonists↗
Unusual thickness-dependent thermal behavior and anticlinic coupling in chiral smectic free-standing liquid-crystal films.
We observe, in free-standing films of a chiral smectic liquid crystal, a series of discrete transitions in the relative orientation of the tilt of the interior and surface layers. These transitions include a remarkable reentrant synclinic-anticlinic-synclinic ordering sequence of the film surfaces in the presence of an electric field upon cooling. The profiles of the associated heat-capacity anomalies are found to be strongly thickness dependent and exhibit a novel crossover behavior in reduced dimensions. We measure the anticlinic coupling between tilted surface layers in the smectic- A phase.
Journal Article↗
Association of bovine papillomavirus type 1 with microtubules.
Transport of BPV-1 virus from the cell membrane to the nucleus was studied in vitro in CV-1 cells. At reduced temperature (4 degrees C), BPV-1 binding to CV-1 cells was unaffected but there was no transport of virions across the cytosol. Electron microscopy showed BPV-1 virions in association with microtubules in the cytoplasm, a finding confirmed by co-immunoprecipitation of L1 protein and tubulin. Internalization of virus was unimpaired in cells treated with the microtubule-depolymerizing drug nocodazole but virions were retained in cytoplasmic vesicles and not transported to the nucleus. We conclude that a microtubule transport mechanism in CV-1 cells moves intact BPV-1 virions from the cell surface to the nuclear membrane.
Active Transport, Cell Nucleus↗
Catalytic asymmetric coupling of 2-naphthols by chiral tridentate oxovanadium (IV) complexes.
A series of chiral oxovanadium(IV) complexes derived from tridentate N-3,5-substituted and N-3,4-benzo- and N-5,6-benzo-salicylidene-alpha-amino acids can serve as efficient catalysts for the enantioselective oxidative couplings of various 3-, 6-, and 7-substituted 2-naphthols under O(2). The best scenario involves the use of a vanadyl complex arising from 2-hydroxy-1-naphthaldehyde and valine (or phenylalanine) in CCl(4), leading to BINOLs in good yields (75-100%) and with enantioselectivities of up to 68%.
Journal Article↗
Syntheses of chromium pentacarbonyl derivatives of arsenic(V) and antimony(V). contrasting chemical reactivity with organic halogen derivatives.
We have synthesized a new series of chromium-group 15 dihydride and hydride complexes [H(2)As(Cr(CO)(5))(2)](-) (1) and [HE(Cr(CO)(5))(3)](2)(-) (E = As, 2a; E = Sb, 2b), which represent the first examples of group 6 complexes containing E-H fragments. The contrasting chemical reactivity of 2a and 2b with organic halogen derivatives is demonstrated. The reaction of 2a with RBr (R = PhCH(2), HC triple bond CCH(2)) produces the RX addition products [(R)(Br)As(Cr(CO)(5))(2)](-) (R = PhCH(2), 3; R = C(3)H(3), 4), while the treatment of 2b with RX (RX = PhCH(2)Br or HC triple bond CCH(2)Br, CH(3)(CH(2))(5)C(O)Cl) forms the halo-substituted complexes [XSb(Cr(CO)(5))(3)](2-) (X = Br, 5; X = Cl, 6). Moreover, the dihaloantimony complexes [XX'Sb(Cr(CO)(5))(2)](-) can be obtained from the reaction of 2b with the appropriate organic halides. In this study, a series of organoarsenic and antimony chromium carbonyl complexes have been synthesized and structurally characterized and the role of the main group on the formation of the resultant complexes is also discussed.
Journal Article↗
Increased fetal nuchal fold leading to prenatal diagnosis of ring chromosome 15.
We report on the prenatal diagnosis of ring chromosome 15 in a fetus with increased nuchal fold and intrauterine growth restriction (IUGR). A 27-year-old woman gravida 2, para 1 had normal maternal serum screen tests in the early second trimester of the index pregnancy. Fetal nuchal fold thickening up to 8 mm was incidentally found during the routine obstetric ultrasound scan at 20 weeks' gestation. Amniocentesis was undertaken and the fetal karyotype was found to be 46,XY,r(15) on cytogenetic study. Fluorescence in situ hybridization (FISH) using a telomeric probe of chromosome 15 demonstrated a terminal deletion on the q arm of the ring-shaped chromosome 15. This is the first report of a prenatally diagnosed case of ring chromosome 15. Moreover, nuchal fold thickness in the second trimester may have a role in its prenatal diagnosis.
Abortion, Induced↗
Preimplantation genetic diagnosis (PGD), a collaborative activity of clinical genetic departments and IVF centres.
Preimplantation genetic diagnosis (PGD) requires the combined efforts of geneticists and workers in the field of reproductive medicine. This was studied on the basis of a questionnaire, sent to 35 members of the PGD Consortium of the European Society of Human Reproduction and Embryology (ESHRE). A reply was obtained from 20 centres. They represent the majority of activities in the field of PGD in the world. It is obvious that many of the activities (in vitro fertilisation, embryo culture and biopsy) take place in IVF units while others (counselling and diagnosis) are the responsibility of genetic diagnostic centres. The distances between both units vary considerably. In all but one centre sex determination is offered. Aneuploidy screening is offered in 13 out of 20 centres. PGD of translocations and other structural chromosome abnormalities is offered in all but one centre. The number of monogenic diseases offered varies considerably. In comparison to prenatal diagnosis PGD is more expensive. The majority of these costs are due to the IVF or ICSI procedure. The charges for PGD vary between about 600 euro and 4000 euro. In 16 out of 20 centres the parents to be must sign an informed consent form.
Aneuploidy↗
Minimal access thoracic surgery for esophageal hemangioma.
Esophageal hemangioma is a rare tumor. This report describes the case of a 69-year-old woman with an esophageal tumor at the middle portion of the esophagus. The patient was successfully treated with minimal access thoracic surgery, and at the 6 month follow-up, the patient was free of any symptoms or recurrence.
Aged↗