Pattern structures on generalized nonlinear Schrödinger equations with various nonlinear terms.
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Journal Article↗
Biomedical subjects
C Zhou
Publications and source records attributed to C Zhou.
Halotolerance of Methanobacterium thermoautotrophicum delta H and Marburg.
Methanobacterium thermoautotrophicum delta H and Marburg were adapted to grow in medium containing up to 0.65 M NaCl. From 0.01 to 0.5 M NaCl, there was a lag before cell growth which increased with increasing external NaCl. The effect of NaCl on methane production was not significant once the cells began to grow. Intracellular solutes were monitored by nuclear magnetic resonance (NMR) spectroscopy as a function of osmotic stress. In the delta H strain, the major intracellular small organic solutes, cyclic-2,3-diphosphoglycerate and glutamate, increased at most twofold between 0.01 and 0.4 M NaCl and decreased when the external NaCl was 0.5 M. M. thermoautotrophicum Marburg similarly showed a decrease in solute (cyclic-2,3-diphosphoglycerate, 1,3,4,6-tetracarboxyhexane, and L-alpha-glutamate) concentrations for cells grown in medium containing > 0.5 M NaCl. At 0.65 M NaCl, a new organic solute, which was visible in only trace amounts at the lower NaCl concentrations, became the dominant solute. Intracellular potassium in the delta H strain, detected by atomic absorption and 39K NMR, was roughly constant between 0.01 and 0.4 M and then decreased as the external NaCl increased further. The high intracellular K+ was balanced by the negative charges of the organic osmolytes. At the higher external salt concentrations, it is suggested that Na+ and possibly Cl- ions are internalized to provide osmotic balance. A striking difference of strain Marburg from strain delta H was that yeast extract facilitated growth in high-NaCl-containing medium. The yeast extract supplied only trace NMR-detectable solutes (e.g., betaine) but had a large effect on endogenous glutamate levels, which were significantly decreased. Exogenous choline and glycine, instead of yeast extract, also aided growth in NaCl-containing media. Both solutes were internalized with the choline converted to betaine; the contribution to osmotic balance of these species was 20 to 25% of the total small-molecule pool. These results indicate that M. thermoautotrophicum shows little changes in its internal solutes over a wide range of external NaCl. Furthermore, they illustrate the considerable differences in physiology in the delta H and Marburg strains of this organism.
2,3-Diphosphoglycerate↗
[A comparison between "moist ointment" and 0.25% iodophor, silver sulfadiazine paste and 0.1% rivanol in the treatment of deep II degree burn wounds].
One hundred and fifteen patients suffering from deep II degree burn were randomly divided into four groups, and "Moist ointment," 0.25% iodophor, silver sulfadiazine paste and 0.1% rivanol were respectively used as topical agents. Their effects were observed and compared. The results showed that "Moist ointment" group was significantly inferior to other groups in respects of healing of wound surface, bacteriostatic property, cost of treatment and formation of hyperplastic scar. Therefore, we suggested that the use of moist ointment in the treatment of deep II degree burn wound should be prohibited.
Administration, Topical↗
[Observation of cochlear microcirculation in experimental endolymphatic hydrops].
30 guinea pigs were made as a model of endolymphatic hydrops by obliteration of endolymphatic sac and duct. Cochlear microcirculation of the lateral wall in the third turn was observed and recorded. The diameters and velocities of the vessels were analysed in IBAS image system. The stria vascular vessels and spiral ligament vessels were analysed respectively. The data showed: 1. 1, 2 and 3 months after operation, the diameter of SLV averaely decreased 0.80 microns, 0.87 microns, 1.21 microns (P < 0.05) respectively and velocity decreased 100.8 microns/s, 141.0 microns/s, 136.0 microns/s (P < 0.05) respectively. 2. The diameter of SVV dilated 3 months after operation. With the elapse of time, SVV had a dilation tendency. These indicated that hydrops effect different changes in SLV and SVV. The overpressure of endolymphatic fluid may be the possible cause of changes in SVV and SLV.
Animals↗
Effects of liuwei dihuang wan [symbol: see text:bd and some other TCM drugs on bone biomechanics and serum 25 (OH)D3 content in rats.
After a relatively long-term injection of hydrocortisone into rats, the strength of bone (anti-stress capacity) reduced evidently, while the rigidity (anti-deformity capacity) increased markedly (ie, bone fragility elevated). At the same time, the content of serum 25(OH)D3 decreased remarkably. After oral administration of Liuwei Dihuang Wan ([see symbol: see text]), anti-stress capability of bone increased evidently and its anti-deformity capability returned to normal; however, there was no elevation of serum 25(OH)D3 content. The effect of Longmu Zhuanggu Chongji ([see symbol: see text]) or Jisheng Shenqi Wan (see symbol: see text]) was lower than that of Liuwei Dihuang Wan. The experiments suggests that Liuwei Dihuang Wan is beneficial to preventing and curing osteoporosis, but no correlation between its mechanism and the metabolism of 25(OH)D3 was demonstrated.
Animals↗
Osmoregulatory alterations in myo-inositol uptake by bovine lens epithelial cells. Part 4: Induction pattern of Na(+)-myo-inositol cotransporter mRNA under hypertonic conditions denoting an early-onset, interactive, protective mechanism against water stress.
PURPOSE: To examine the effect of hypertonicity on the induction of the Na(+)-myo-inositol (Na(+)-MI) cotransporter(s) in cultured bovine lens epithelial cells (BLECs). METHODS: Na(+)-MI cotransporter 626-bp reverse transcription-polymerase chain reaction product amplified from lens cell RNA and aldose reductase (AR) cDNA probes were used to measure respective mRNA content by Northern blot analysis. RESULTS: Northern blot analysis of BLEC mRNA hybridized to Na(+)-MI cotransporter cDNA showed that Na(+)-MI cotransporter mRNA increased when secondary cultures of BLECs were exposed to physiological medium supplemented with 116 mmol/l NaCl. A time course further revealed a maximal increase in Na(+)-MI cotransporter mRNA by 8 hours. Thereafter, the level of Na(+)-MI cotransporter mRNA steadily declined for the duration of the 72-hour incubation period despite continuous exposure of BLECs to hypertonicity. AR mRNA levels maximally increased by 24 h of cell exposure to hypertonic condition. Unlike Na(+)-MI cotransporter mRNA, AR mRNA remained elevated throughout the duration of the experiment. Hypertonic exposure resulted in a steady state accumulation of myo-inositol and sorbitol for 6 days. Inhibition of sorbitol formation prompted the intracellular myo-inositol content to a higher level. CONCLUSIONS: These data suggest that enhanced MI transport and accumulation, as an adaptive osmoregulatory response to hypertonicity in cultured BLECs, is a primary, early-onset, protective mechanism against water stress, succeeded by, enhanced sorbitol formation and accumulation, a secondary, late-onset protective mechanism. The lens appears to respond to the preliminary stages of hyperosmotic stress by induction of Na(+)-MI cotransporter mRNA, indicating that the myo-inositol carrier protein(s) play an initial responsive role in the management of osmotic stress. Lens water stress management is interactive because myo-inositol and sorbitol levels are regulated in concert.
Aldehyde Reductase↗
Osmoregulatory alterations in myo-inositol uptake by bovine lens epithelial cells. Part 2: Cloning of a 626 bp cDNA portion of a Na+/myo-inositol cotransporter, an osmotic shock protein.
PURPOSE: Bovine lens epithelial cells (BLECs) accumulate osmotically active organic solutes (i.e., osmolytes) including myo-inositol when exposed to hypertonic stress (osmotic shock). In hypertonic medium, the increase in myo-inositol accumulation is attributed to an elevation in activity of Na+/myo-inositol cotransporter(s). The authors report the nature of the hypertonicity-induced enhancement of myo-inositol uptake in cultured BLECs by amplifying a 626 bp cDNA from lens cell RNA. METHODS: A portion of cDNA encoding a Na+/myo-inositol cotransporter was isolated from cultured BLECs using PCR primers designed from an established myo-inositol transporter from Madin-Darby canine kidney (MDCK) cells. Using the reverse transcription-polymerase chain reaction, a 626 bp PCR product was amplified. Its nucleic acid sequence was determined by the dideoxynucleotide method using Sequenase kit. Na+/Myo-inositol cotransporter mRNA expression in the cultured cells was demonstrated under physiological and hypertonic conditions by northern analysis of poly(A)+ RNA using the lens cell 626 bp cDNA as probe. RESULTS: The BLEC cDNA sequence was 92% identical with the Na+/myo-inositol cotransporter of MDCK cells. Myo-inositol transporter mRNA was demonstrated in cultured BLECs and was significantly induced by hypertonic stress. CONCLUSIONS: These data suggest that cultured bovine lens epithelial cell adaptation to hypertonicity involves intracellular accumulation of small organic osmolytes (i.e., myo-inositol) through elevation of myo-inositol uptake activity resulting from the upregulation of transporter mRNA.
Amino Acid Sequence↗
Substrate requirements of bacterial phosphatidylinositol-specific phospholipase C.
A series of symmetric short-chain phosphatidylinositols (PI), including dihexanoyl-PI, diheptanoyl-PI (racemic as well as D and L forms), and 2-methoxy inositol-substituted diheptanoyl-PI, have been synthesized, characterized, and used to investigate key mechanistic questions about phosphatidylinositol-specific phospholipase C (PI-PLC) from Bacillus thuringiensis. Key results include the following: (i) bacterial PI-PLC exhibits a 5-6-fold "interfacial activation" when its substrate is present in an interface as opposed to existing as a monomer in solution (in fact, the similarity to the activation observed with nonspecific PLC enzymes suggests a similarity in activation mechanisms); (ii) the 2-OH must be free since the enzyme cannot hydrolyze diheptanoyl-2-O-methyl-PI (this is most consistent with the formation of inositol cyclic 1,2-phosphate as a necessary step in catalysis); (iii) the inositol ring must have the D stereochemistry (the L-inositol attached to the lipid moiety is neither a substrate nor an inhibitor); and (iv) the presence of noninhibitory L-PI with the D-PI substrate relieves the diacylglycerol product inhibition detected at approximately 30% hydrolysis.
Bacillus thuringiensis↗
Establishment of National Quality Control Reference Panels and Requirements for Hepatitis B diagnosis reagents in China.
A National Quality Control Reference Panel for Hepatitis B Diagnostic Kits has been established. Markers for these standards which were prepared include National Standards for HBsAg and anti-HBs calibrated against WHO International Standards. In addition, Reference Panels for HBeAg, anti-HBe, anti-HBc, anti-HBc IgM and HBV were established and National Requirements set. These panels have been used for the nationwide evaluation of HB kits and for licensing purposes.
China↗
Expression of dopamine by chick primary sensory neurons and their related targets.
The expression of dopamine by primary sensory neurons and their peripheral projections was studied in the chick dorsal root ganglion by means of immunocytochemical procedures. Within the sensory neurons, dopamine immunoreactivity is first expressed by 0.8% of cells at E10 and reaches a percentage of 5.6% before hatching. After hatching, 8.6% of neurons, belonging to both the A and B classes of sensory neurons, exhibit a clear immunostaining. According to the immunostaining of nerve terminals located in various peripheral target tissues, these immunoreactive neurons are responsible, at least in part, for the sensory innervation of the skin and paravertebral ganglia. The results provide evidence that different classic neurotransmitters may be expressed by specific subpopulations of primary sensory neurons expressing various somatic and autonomic sensory functions in relation to specific targets.
Animals↗
Expression of gamma-aminobutyric acid and calcium binding protein-parvalbumin by chick motoneurons.
The expression of calcium binding protein parvalbumin (PV) and gamma-aminobutyric acid (GABA) was studied in the chick motoneurons by using pre- and postembedding immunocytochemistry. Our data reveal that PV and GABA are colocalized in the majority, but not all, of chick lumbo-sacral spinal motoneurons innervating the somatic muscles. It is suggested that, in this neuromuscular system, GABA does not act as a classical inhibitory neurotransmitter but, combined with calcium, could be involved, at least in part, in the maintenance of neurons and the prevention of cell death as in certain neurodegenerative disorders.
Animals↗
Mutation analysis of Saccharomyces cerevisiae CDC6 promoter: defining its UAS domain and cell cycle regulating element.
Using beta-galactosidase as the reporter gene, we carried out mutagenesis experiments to investigate the 5' promoter region of the CDC6 gene. Our results showed that the DNA element, between -262 and -170, is important for the upstream activating sequence (UAS) activities. On the basis of the DNA sequence, there is a Mlu I (-204) and a Mlu I-like (-216) element located within the middle of the UAS region. Insertion and deletion mutagenesis analysis of the Mlu I sequence has indicated that the internal CGCG sequence of the Mlu I site (ACGCGT) is important for gene expression. Furthermore, when DNA elements containing the Mlu I sites were subcloned into the tester plasmid, periodic expression of a reporter gene throughout the cell cycle was observed, as evidenced by the beta-galactosidase activities and lacZ mRNA. Because the possible transcriptional initiation sites of the CDC6 transcript have been previously defined (Zhou and Jong, 1990, J. Biol. Chem. 264, 9022-9029), we propose a model regarding the construct of the CDC6 promoter region. This 5' promoter construct contains a UAS region and a Mlu I element (MCB box) typical of a family of cell cycle-regulated genes involved in DNA metabolism. Previous genetic studies have not completely defined the CDC6 execution point in the functional yeast cell cycle map. Our results favor the possibility that the CDC6 gene is required, and directly involved, in the initiation of DNA replication.
Bacterial Proteins↗
Comparison of trans-dominant inhibitory mutant human immunodeficiency virus type 1 genes expressed by retroviral vectors in human T lymphocytes.
trans-Dominant inhibitory mutant versions of the human immunodeficiency virus type 1 (HIV-1) regulatory genes tat and rev have previously been described. We have constructed a series of retroviral vectors to transduce these genes and compare their inhibitory activities. The inhibitory activities were measured with transient transfection assays by using a reporter which expresses an HIV-1 gag-Escherichia coli lacZ fusion protein with strict dependence on coexpression of both tat and rev. Additionally, the vectors were packaged as amphotropic virions and used to stably transduce human CEM T lymphocytes. The transduced CEM cells were challenged with HIV-1, and the effects of the mutant HIV-1 genes were determined by measuring the levels of HIV-1 p24gag produced. A tat gene substituted at amino acid 41 (tatk41a) retained partial trans-activating activity and lacked inhibitory activity. A tat gene with a premature stop codon at amino acid 54 (tat54ter) showed moderate trans-dominant inhibition of the reporter plasmid but failed to significantly inhibit HIV-1 replication. The M10 rev mutant, with a 2-amino-acid substitution, showed strong trans-dominant inhibitory activity both in the reporter plasmid and in the HIV-1 infection assay. The greatest inhibition of HIV-1 growth was seen when M10 was expressed under the transcriptional control of a human cytomegalovirus promoter; slightly less inhibition was achieved when expression of M10 was controlled by the Moloney murine leukemia virus long terminal repeat, and minimal inhibition was seen when the HIV-1 long terminal repeat controlled the M10 gene. These results demonstrate the potential utility of retroviral vectors expressing trans-dominant inhibitory mutant HIV-1 genes for gene therapy approaches to AIDS.
Acquired Immunodeficiency Syndrome↗
Dynamic properties and the two-point correlation function for electrons in localized coherent Langmuir fields.
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Basic dynamic properties of the high-order nonlinear Schrödinger equation.
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Density of states and tunneling spectra in two-dimensional d-wave superconductors.
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Journal Article↗
Isolation and characterization of bovine gingival proteoglycans versican and decorin.
1. We have isolated, chemically and immunologically characterized versican and decorin from bovine gingiva. 2. Versican was of large molecular weight and the molecular size of the core protein was estimated to be greater than 200 kDa. 3. The glycosaminoglycan chains were susceptible to chondroitinase ABC and N-linked oligosaccharides were present on the protein core of the molecule. 4. Immunological studies provided evidence that a hyaluronic acid binding region was present in the core protein of versican. 5. The overall structure was similar to that of versican isolated from bovine sclera. 6. Decorin had a molecular weight of 102 kDa and its glycosaminoglycan chain was completely digested by specific glycosidases. 7. The partially deglycosylated core protein had a molecular weight of 55 kDa and N-linked oligosaccharides were present on the molecule.
Amino Acids↗
Immunolocalization of beta 1 integrins in human gingival epithelium and cultured keratinocytes.
Beta 1 integrins are cell surface receptors for extracellular matrix binding. We have recently shown that these receptors may also play a role in cell-cell binding of human epidermal keratinocytes. In this study we used immunofluorescence and confocal laser scanning microscopy to localize beta 1 integrins in frozen sections of human gingiva and cultures of human gingival keratinocytes. The results show that beta 1 integrin polypeptides, localized by monoclonal and polyclonal antibodies, were detected mainly in the basal layer of the keratinized epithelium. There was also scattered staining in connective tissue fibroblasts, nerves, and blood vessel walls. In the basal layer, the integrins were found around the entire periphery of the basal keratinocytes. Furthermore, confocal laser scanning microscopy (CLSM) revealed that most of the staining was in fact localized in dot-like structures at the lateral cell membranes of neighboring basal cells. In cultured human gingival keratinocytes maintained in low calcium (0.15 mM) conditions beta 1 integrins were localized in several different structures: trails which were left behind when the cells moved in culture, dots underneath the cells, around the nucleus, and in cell-cell contacts. The trails were also found to contain fibronectin and type IV collagen but not laminin. Switching the keratinocytes to high calcium (1.2 mM) conditions induced the formation of cell-cell contacts which were strongly positive for beta 1 integrins. No fibronectin or type IV collagen was found in cell-cell contact sites.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗