Biomedical subjects

C Y Wang

Publications and source records attributed to C Y Wang.

At least 55 records · Page 3Linked to original sources

PubMed2002

Fabrication and properties of spray-dried nanofeatured spherical Ni(OH)2 materials.

Spherical agglomerates of nanostructured beta-phase Ni(OH)2 with the general formula Ni1-xCox(OH)2 (x = 0, 0.1, 0.3) for use as cathode materials were produced by a modified method including coprecipitation of Ni or Ni composite hydroxide and further spray drying of the precipitated and washed slurry. This process leads to the formation of spherical agglomerate particles with a narrow Gaussian-type distribution range. The method permits faster and cheaper production of cathode materials with a higher specific surface area and similar or better capacity and cycle life compared with the materials prepared via conventional technology.

Aerosols↗

PubMed2002

Potentiation of tumor necrosis factor-mediated apoptosis of oral squamous cell carcinoma cells by adenovirus-mediated gene transfer of NF-kappaB inhibitor.

Oral squamous cell carcinoma (SCC) is a malignant tumor which is often resistant to cancer-therapy-mediated apoptosis. The stress-responsive transcription factor nuclear factor kappa B (NF-kappaB), which has been found to be associated with SCC development, plays an essential role in the suppression of tumor necrosis factor (TNF)-mediated apoptosis. Here, we report that an adenovirus-mediated gene transfer of NF-kappaB inhibitor, super-repressor I kappa B alpha (Adv-SR-IkappaBalpha), blocked TNF-induced NF-kappaB activation and sensitized oral SCC cells to TNF killing. Additionally, we found that the inhibition of NFkappaB by Adv-SR-IkappaBalpha enhanced TNF-mediated caspase-8 and -3 activation. These results suggest that NF-kappaB activation is a general mechanism by which oral squamous carcinoma cells are resistant to TNF killing and provide a molecular basis for gene therapy of oral cancer by IkappaBalpha gene transfer in vivo.

Adenoviridae↗

PubMed2001

Ca(2+) binding protein frequenin mediates GDNF-induced potentiation of Ca(2+) channels and transmitter release.

Molecular mechanisms underlying long-term neurotrophic regulation of synaptic transmission and plasticity are unknown. We report here that long-term treatment of neuromuscular synapses with glial cell line-derived neurotrophic factor (GDNF) potentiates spontaneous and evoked transmitter release, in ways very similar to presynaptic expression of the Ca(2+) binding protein frequenin. GDNF enhances the expression of frequenin in motoneurons, and inhibition of frequenin expression or activity prevents the synaptic action of GDNF. GDNF also facilitates Ca(2+) influx into the nerve terminals during evoked transmission by enhancing Ca(2+) currents. The effect of GDNF on Ca(2+) currents is blocked by inhibition of frequenin expression, occluded by overexpression of frequenin, and is selective to N-type Ca(2+) channels. These results identify an important molecular target that mediates the long-term, synaptic action of a neurotrophic factor.

Animals↗

PubMed2001

Evaluation and treatment of postmenopausal osteoporosis.

Osteoporosis is a prevalent condition among elderly women and is associated with an increased risk for fractures. With the burgeoning size of the elderly population, a practitioner is likely to face many questions regarding the evaluation and management of postmenopausal osteoporosis. This review discusses and compares available therapies. All women should have adequate calcium and vitamin D intake. Women diagnosed as having osteoporosis should be evaluated for secondary causes of osteoporosis and risk factors for falls. For women with postmenopausal osteoporosis, therapy with hormone replacement, bisphosphonates (alendronate sodium or risedronate sodium), raloxifene hydrochloride, or calcitonin should be considered. The results of ongoing studies will help refine the strategies used for management of postmenopausal osteoporosis.

Aged↗

PubMed2001

The autoimmune regulator (AIRE) is a DNA-binding protein.

The autoimmune regulator (AIRE) protein is a putative transcription regulator with two plant homeodomain-type zinc fingers, a putative DNA-binding domain (SAND), and four nuclear receptor binding LXXLL motifs. We have shown here that in vitro, recombinant AIRE can form homodimers and homotetramers that were also detected in thymic protein extracts. Recombinant AIRE also oligomerizes spontaneously upon phosphorylation by cAMP dependent protein kinase A or protein kinase C. Similarly, thymic AIRE protein is phosphorylated at the tyrosine and serine/threonine residues. AIRE dimers and tetramers, but not the monomers, can bind to G-doublets with the ATTGGTTA motif and the TTATTA-box. Competition assays revealed that sequences with one TTATTA motif and two tandem repeats of ATTGGTTA had the highest binding affinity. These findings demonstrate that AIRE is an important DNA binding molecule involved in immune regulation.

Amino Acid Sequence↗

PubMed2001

Suppression of tumor necrosis factor-mediated apoptosis by nuclear factor kappaB-independent bone morphogenetic protein/Smad signaling.

The activation of nuclear factor kappaB (NF-kappa B) plays a pivotal role in the regulation of tumor necrosis factor (TNF)-mediated apoptosis. However, little is known about the regulation of TNF-mediated apoptosis by other signaling pathways or growth factors. Here, unexpectedly, we found that bone morphogenetic protein (BMP)-2 and BMP-4 inhibited TNF-mediated apoptosis by inhibition of caspase-8 activation in C2C12 cells, a pluripotent mesenchymal cell line that has the potential to differentiate into osteoblasts depending on BMP stimulation. Utilizing both a trans-dominant IkappaBalpha inhibitor of NF-kappaB expressed in C2C12 cells and IkappaB kinase beta-deficient embryonic mouse fibroblast, we show that BMP-mediated survival was independent of NF-kappaB activation. Rather, the antiapoptotic activity of BMPs functioned through the Smad signaling pathway. Thus, these findings provide the first report of a BMP/Smad signaling pathway that can inhibit TNF-mediated apoptosis, independent of the prosurvival activity of NF-kappaB. Our results suggest that BMPs not only stimulate osteoblast differentiation but can also promote cell survival during the induction of bone formation, offering new insight into the biological functions of BMPs.

Animals↗

PubMed2001

Molecular cloning and characterization of the mouse and human TUSP gene, a novel member of the tubby superfamily.

We report here the cloning and characterization of a novel gene belonging to the tubby superfamily proteins (TUSP) in mouse and human. The mouse Tusp cDNA is 9120 bp in length and encodes a deduced protein of 1547 amino acids, while the human TUSP gene is 11,127 bp and encodes a deduced protein of 1544 amino acids. The human and mouse genes are 87% identical for their nucleotide sequences and 85% identical for their amino acid sequences. The protein sequences of these genes are 40-48% identical to other tubby family proteins at the C-terminal conserved 'tubby domain'. In addition, the TUSP proteins contain a tubby signature motif (FXGRVTQ), two bipartite nuclear localization signals (NLSs) at the C-terminal, two proline-rich regions, one WD40 repeat region and one suppressor of cytokines signaling domain. Transfection assay with green fluorescent protein-tagged TUSP expression constructs showed that the complete TUSP protein and the N-terminal portion of TUSP are localized in the cytoplasm but the C-terminal portion with the two NLSs produced distinct dots or spots localized in the cytoplasm. Northern blotting analysis showed that the major transcript with the complete coding sequence is expressed mainly in the brain, skeletal muscle, testis and kidney. Radiation hybrid mapping localized the mouse gene to chromosome 17q13 and the human TUSP gene to chromosome 6q25-q26 near the type 1 diabetes gene IDDM5. However, association analysis in diabetic families with a polymorphic microsatellite marker did not show any evidence for association between TUSP and type 1 diabetes. The precise biological function of the tubby superfamily genes is still unknown; the highly conserved tubby domain in different species, however, suggests that these proteins must have fundamental biological functions in a wide range of multi-cellular organisms.

Adaptor Proteins, Signal Transducing↗

PubMed2001

A retro-inverso Prosaptide D5 promotes a myelination process in developing rats.

The myelinotrophic action of Prosaptide D5 was investigated in developing rats. Sulfatide concentrations in brain and sciatic nerve were determined to assess the development of myelination. Subcutaneous D5-injection significantly increased sulfatide concentrations in both brain and sciatic nerve by 250 and 150% over controls, respectively. D5 promoted ERK phosphorylation in iSC Schwann cells similar to prosaposin. The results showed that D5 treatment stimulated a myelination process in developing rat.

Aging↗

PubMed2001

Nuclear factor-kappa B-inducible death effector domain-containing protein suppresses tumor necrosis factor-mediated apoptosis by inhibiting caspase-8 activity.

Activation of the transcription factor nuclear factor-kappa B (NF-kappa B) has been found to play an essential role in the inhibition of tumor necrosis factor (TNF)-mediated apoptosis. NF-kappa B regulates several antiapoptotic molecules including inhibitors of apoptosis, Bcl-2 family proteins (A1 and Bcl-X(L))(,) and IEX-IL. Here we report that the expression of a small death effector domain (DED)-containing protein, NDED (NF-kappa B-inducible DED-containing protein), depends on the activation of NF-kappa B. The inhibition of NF-kappa B by I kappa B alpha, a natural inhibitor of NF-kappa B, suppressed NDED mRNA expression induced by TNF. The restoration of NDED in NF-kappa B null cells inhibited TNF-induced apoptosis. Intriguingly, unlike the caspase-8 inhibitor cellular FADD-like interleukin-1 beta converting enzyme-inhibitory protein (c-FLIP), NDED suppressed TNF-mediated apoptosis by inhibiting TNF-induced caspase-8 enzymatic activity but not the processing of caspase-8. Furthermore, NDED could not inhibit etoposide-mediated apoptosis that is independent of caspase-8 activation. Our results provide the first demonstration that NF-kappa B transcriptionally induces the DED-containing protein to suppress TNF-mediated apoptosis by inhibiting caspase-8 activity, which offers new insight into the antiapoptotic mechanism of NF-kappa B.

Apoptosis↗

PubMed2001

Usefulness of an individualized balance and gait intervention programme based on the problem-oriented assessment of mobility in nursing home residents.

PURPOSE: To examine the usefulness of an individualized balance and gait training proramme according to the specific problems identified from the problem-oriented assessment of mobility (POAM) in residents of a nursing home. METHOD: The clinical records of 74 NH residents (49 female, 25 male) who were consecutively referred to physical therapy for problems related to poor balance or gait or a recent fall in a 2 year period were reviewed retrospectively for the study. According to the medical charts, patients had received a four week (20 sessions) problem-oriented exercise programme that specifically targeted balance and gait deficits identified from the POAM and the retest had been done after four weeks of training. RESULTS: The mean initial and final balance scores were 8.47+/-3.80. and 10.77+ /-3.37. respectively, and the mean gait scores were 6.73+/-2.30 initially and 7.71+/-1.95 finally. A Wilcoxon signed-rank comparison of the initial and final POAM indicated that significant improvement occurred in the balance scores (Z = 5.345, p < 0.0001) and the gait scale (Z = 3.589, p < 0.0001) in this group. Item analysis demonstrated the number of patients who improved or did not change on individual items. CONCLUSIONS: Both balance and gait were significantly improved after a four-week intervention programme based on the deficits identified by POAM. The POAM is a useful tool to guide the clinician to target specific balance and gait deficits for individual nursing home elders.

Aged↗

PubMed2001

Molecular cloning and characterization of a novel mammalian endo-apyrase (LALP1).

Here we describe the cloning, localization, and characterization of a novel mammalian endo-apyrase (LALP1) in human and mouse. The predicted human LALP1 gene encodes a 604-amino acid protein, whereas the mouse Lalp1 gene encodes a 606-amino acid protein. The human and mouse genes have 88% amino acid sequence identity. These genes share considerable homologies with hLALP70, a recently discovered mammalian lysosomal endo-apyrase. The human LALP1 gene resides on chromosome 10q23-q24 and contains 12 exons and 11 introns covering a genomic region of approximately 46 kilobase pairs. The subcellular localization and enzymatic activity of LALP1 indicated that LALP1 is indeed an endo-apyrase with substrate preference for nucleoside triphosphates UTP, GTP, and CTP.

Amino Acid Sequence↗

PubMed2001

Wnt-1 signaling inhibits apoptosis by activating beta-catenin/T cell factor-mediated transcription.

Wnt signaling plays a critical role in development and oncogenesis. Although significant progress has been made in understanding the downstream signaling cascade of Wnt signaling, little is known regarding Wnt signaling modification of the cell death machinery. Given that numerous oncogenes transform cells by providing cell survival function, we hypothesized that Wnt signaling may inhibit apoptosis. Here, we report that cells expressing Wnt-1 were resistant to cancer therapy-mediated apoptosis. Wnt-1 signaling inhibited the cytochrome c release and the subsequent caspase-9 activation induced by chemotherapeutic drugs, including both vincristine and vinblastine. Furthermore, we found that Wnt-1-mediated cell survival was dependent on the activation of beta-catenin/T cell factor (Tcf) transcription. Inhibition of beta-catenin/Tcf transcription by expression of the dominant-negative mutant of Tcf-4 blocked Wnt-1-mediated cell survival and rendered cells sensitive to apoptotic stimuli. These results provide the first demonstration that Wnt-1 inhibits cancer therapy-mediated apoptosis and suggests that Wnt-1 may exhibit its oncogenic potential through a mechanism of anti-apoptosis.

Animals↗

PubMed2001

Rapid decrease of RNA level of a novel mouse mitochondria solute carrier protein (Mscp) gene at 4-5 weeks of age.

We cloned a novel mouse gene that encodes a protein with homology to the mitochondria solute carrier proteins (Mscp). The major full-length Mscp transcript contains 4112 bp of cDNA and a deduced protein of 338 amino acids. The Mscp protein shares 50%, 40%, and 39% sequence identity with the C. elegans hypothetical protein T26089 and the yeast mitochondria carrier proteins MRS3 and MRS4, respectively. It also showed homology with the uncoupling proteins (UCP1, UCP2, and UCP3; 22%, 24%, and 29% identity, respectively). The protein has six transmembrane domains and three mitochondria energy-transfer protein signature motifs, which are conserved among all the members of mitochondria carrier protein family. Northern analysis indicated that the Mscp gene is highly expressed in the spleen. Using cDNA microarray and Northern analysis, we have shown a significant decrease of the splenic Mscp mRNA levels around 4-5 weeks of age in several mouse strains including C57BL/6J, nonobese diabetic (NOD), and several NOD-congenic mice. These results suggest that the Mscp gene is decreased during splenic lymphocyte maturation in these mice.

Amino Acid Sequence↗

PubMed2001

A new trihydroxy fatty acid from the ascomycete, Chinese truffle Tuber indicum.

From the chloroform/methanol extract of the fruiting bodies of the ascomycete Chinese truffle Tuber indicum Cooke et Massee, a new trihydroxylated monounsaturated fatty acid (1) has been isolated. The structure of this new linoleic acid-derived metabolite was established as 9,10,11-trihydroxy-(12Z)-12-octadecenoic acid by means of spectroscopic and chemical methods. The fatty acid composition of the chloroform-soluble fraction of this fungus was analyzed by gas chromatography-mass spectrometry. The content of the predominant unsaturated fatty acids (oleic and linoleic acids) is as high as 68%. The use of dimethyl disulfide adduct was effective in the determination of the position of the double bond, and the glycol oxidation fission reaction with sodium metaperiodate supported on silica gel was helpful in establishing the location of the trihydroxylic groups in the new fatty acid.

Ascomycota↗

PubMed2001

Capillary supply regions.

The diffusion and consumption of substrate from capillaries are basic in human physiology. The general solution for the concentration in a region containing many parallel non-homogeneous capillaries is found. Except in very special cases, capillary supply regions cannot be approximated by Krogh's cylinder or Voronoi polygonal cylinders.

Capillaries↗

PubMed2001

The inhibitory effects of BmK IT2, a scorpion neurotoxin on rat nociceptive flexion reflex and a possible mechanism for modulating voltage-gated Na(+) channels.

Buthus martensi Karsch IT2 (BmK IT2), a scorpion neurotoxin, was found to display a biphasic inhibitory effect on the C component of the rat nociceptive flexion reflex by subcutaneous injection in vivo, and also on the total Na(+) currents of rat dorsal root ganglion neurons using whole-cell patch clamping. BmK IT2 blocked the tetrodotoxin-resistant (TTX-R) component of the Na(+) currents with a degree of selectivity. The partial block of the TTX-R Na(+) currents, brought about by 0.01 microg/microl BmK IT2, reversed less rapidly and completely than the partial block of the tetrodotoxin-sensitive (TTX-S) current brought about by the same concentration of BmK IT2. These results suggest that the inhibition of the rat nociceptive flexion reflex by BmK IT2 may be attributed to modulation of the different voltage-gated Na(+) channels.

Animals↗

PubMed2001

Armillaramide, a new sphingolipid from the fungus Armillaria mellea.

A new C(18)-phytosphingosine ceramide containing non-hydroxy fatty acid, armillaramide (1), has been isolated together with ergosterol peroxide from the fruiting bodies of the basidiomycete Armillaria mellea. Its structure was established as (2S,3S,4R)-2-hexadecanoylamino-octadecane-1,3,4-triol by spectroscopic and chemical methods.

Agaricales↗

PubMed2001

Metabolism of phenolic compounds during loquat fruit development.

Phenolic compounds in loquat fruit were identified as 5-caffeoylquinic acid (chlorogenic acid), neochlorogenic acid, hydroxybenzoic acid, 5-p-feruloylquinic acid, protocatechuic acid, 4-caffeoylquinic acid, epicatechin, o-coumaric acid, ferulic acid, and p-coumaric acid. Neochlorogenic acid was found to be dominant in the early stages of loquat fruit development. Both the concentrations and types of phenolic compounds were high in young fruit but then decreased steadily during growth. However, the concentration of chlorogenic acid increased during ripening and became predominant in ripe fruit. The large rise in chlorogenic acid concentration appears to be a characteristic of loquat fruit ripening. In all of the cultivars tested, the types of phenolic compounds were similar but the total phenolic content varied from 81.8 to 173.8 mg/100 g of fresh pulp. In the biosynthetic pathway of chlorogenic acid, the enzyme activities of phenylalanine ammonia-lyase (PAL), 4-coumarate:CoA ligase (CL), and hydroxycinnamoyl CoA:quinate hydroxycinnamoyl transferase (CQT) were high at the early stage of growth, diminished to low levels approximately 3 weeks prior to harvest, but then rose to a peak at 1 week before harvest. The changes of these enzyme activities seemed to be associated with variations in chlorogenic acid concentration during development, maturation, and ripening of loquat fruit.

Chlorogenic Acid↗