[Evaluation of the clinical use of calcium channel blockers in psychiatry].
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Bipolar Disorder↗
Biomedical subjects
J Xu
Publications and source records attributed to J Xu.
[The relation between the seed germination and seedling development of Bletilla striata and Mycena osmundicola etc. fungi].
This paper reports the effects of Mycena osmundicola etc. fungi on the seed germination and seedling growth of Bletilla striata. The results showed that B. striata seeds are easily germinated under normal conditions and belong to a special type among Orchidaceae. Fungi promote cotyledon differentiation and growth, as well as rhizoid formation of B. striata protocorms after seeds are sown with fungi. A liquid extract mixture enhanced the percentage of seed germination, and carbinol extract notably accelerated differentiation and growth of the protocorm's cotyledon after seeds were incubated with the liquid extract of Mycena osmundicola-culture products.
Agaricales↗
Laser polarized muonic helium.
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Journal Article↗
Structure and expression of subunit A from the bovine chromaffin cell vacuolar ATPase.
Subunit A of the vacuolar H(+)-ATPase class is thought to be responsible for the ATP hydrolysis which drives proton-pumping. We report here the cloning and sequence determination of the first mammalian cDNA encoding a bovine vacuolar ATPase subunit A from an adrenal medulla cDNA library. Northern blots of bovine adrenal medulla RNA reveal a message of approximately 3.8 kb. The predicted peptide sequence, consisting of 618 amino acids with a calculated molecular weight of 68397 daltons, is similar to the sequences of the three known subunit A proteins. beta-Galactosidase-subunit A fusion proteins were immuno-decorated by an antiserum raised to the subunit A protein from corn coleoptile vacuoles.
Adenosine Triphosphatases↗
Molecular cloning of phosphofructokinase 1 gene from a thermophilic bacterium, Thermus thermophilus.
Phosphofructokinase 1 (PFK1) from Thermus thermophilus differs from other bacterial PFKs in that it is regulated by effector-induced reversible tetramer-dimer conversion rather than conformational change alone. We have cloned its gene and the deduced amino acid sequence was compared with that of other PFKs. While almost all amino acid residues involved in substrate binding sites, which are assigned from crystal structures of other PFKs, are well conserved, some possibly important changes are found at subunit interfaces.
Amino Acid Sequence↗
Comparison of pharmacological agents (aspartate vs. aminophosphonobutyric plus kynurenic acids) to block synaptic transmission from retinal photoreceptors in frog.
The combination of aminophosphonobutyric plus kynurenic acids (APB/Kyn) was compared to aspartate with respect to its ability to block synaptic transmission from photoreceptors. Like aspartate, APB/Kyn blocks photoreceptor synaptic transmission, as monitored by the b- and d-waves of the electroretinogram, by the proximal negative response and M-wave of the proximal retina, and by the light-evoked increase in extracellular K+ concentration in the inner plexiform layer. Unlike aspartate, APB/Kyn has relatively minor effects on retinal resistance, light-evoked changes in K+ and Ca2+ concentrations in the subretinal space, light-evoked changes in subretinal space volume, resting extracellular concentrations of K+ and Ca2+ in the proximal and distal retina, and the c-wave. Effects of APB/Kyn are generally more reversible than effects of Asp. A disadvantage of APB/Kyn is that the a-wave usually becomes smaller and slower. Overall, APB/Kyn disrupts the retina less than aspartate. Therefore, in some situations in which blockade of photoreceptor synaptic transmission is desired, the use of APB/Kyn may be preferable to that of aspartate.
Aminobutyrates↗
Localization of the alpha-like globin gene cluster to region q12 of rabbit chromosome 6 by in situ hybridization.
The rabbit (Oryctolagus cuniculus) alpha-like globin gene cluster (HBAC) contains several block duplications of zeta-, alpha and theta-globin genes. Using in situ hybridizations to metaphase chromosome spreads, the gene cluster has been mapped to region q12 of chromosome 6. Given that human HBAC maps to the short arm of chromosome 16, the mapping of rabbit HBAC to 6q12 confirms the assignment of homology between OCU6q and HSA16p based on similarities of chromosomal banding patterns. In both species, HBAC is in a very G + C-rich region within the most distal band of the chromosome.
Animals↗
Inhibition of succinate-ubiquinone reductase by nitrosalicyl-N-alkylamides.
The abilities of eight nitrosalicyl-N-alkylamides to inhibit succinate-ubiquinone reductase were compared. These compounds possess both a nitro group at 3- or 5-position of the benzyl ring, and a methyl, decyl, dodecyl or tetradecyl group subsituted for the amide hydrogen of salicylamide. The result shows the following: (a) 3-Nitrosalicyl-N-alkylamides are stronger inhibitors than 5-nitrosalicyl-N-alkylamides when they have the same alkyl group. (b) The inhibitory abilities of both 3-and 5-nitrosalicyl-N-alkylamides increase with increasing alkyl group length. (c) Kinetic data show that the inhibition by 3-nitrosalicyl-N-tetradecylamide is noncompetitive with respect to the electron acceptor Q2.
Animals↗
Xanthine oxidase in experimental spinal cord injury.
The excessive generation of free radicals is thought to be one of the major mechanisms leading to tissue injury in various pathological conditions, including ischemia, inflammation, and trauma. Conversion of xanthine dehydrogenase (XDH) to xanthine oxidase (XO) contributes to the formation of superoxide, an oxygen radical. We measured XDH and XO activity using a newly developed fluorometric assay in an experimental spinal cord injury model in rats. XO activity increased by more than 100% 4 h after spinal cord trauma. Total (XDH + XO) activity also increased by 96% during the same period. Allopurinol, an inhibitor of XO (100 mg/kg/day x 2 days, i.p.), completely inhibited plasma and spinal cord XO activity but did not affect posttraumatic edema determined by water content or polymorphonuclear (PMN) cell infiltration reflected by myeloperoxidase (MPO) activity in traumatized spinal cord. These results indicate that XDH conversion to XO may not be the major mechanism of oxygen radical formation in the pathogenesis of vasogenic edema or inflammatory response in this experimental spinal cord injury model in rats.
Allopurinol↗
A sensitive fluorometric method for measurement of vascular permeability in spinal cord injury.
A sensitive fluorometric method was modified for the evaluation of drug action upon vascular permeability in rat spinal cord injury. Fluorescein isothiocyanate-conjugated dextran (FITC-D MW 71,200), used as a macromolecular tracer, was injected iv 2 hours before sacrifice. The optimal pH for FITC-D fluorescence was 8.2. The recovery in spinal cord was 101.4 +/- 4.0% (mean +/- SD). The extent of FITC-D extravasation, expressed as the vascular injury index (VII), was increased in proportion to the trauma force. The peak of VII after trauma was at 2 hours. This fluorometric method is sensitive, simple, and reliable for evaluation of drug effects upon vascular permeability in CNS trauma.
Animals↗
Kininogen and kinin in experimental spinal cord injury.
Activation of the kallikrein-kinin system has been implicated in the pathogenesis of vasogenic brain edema and posttraumatic vascular injury. We determined the levels of kininogen and kinin in an experimental spinal cord injury model in the rat. Kininogen content in traumatized cord segments increased in a time-dependent manner. Western blot analysis showed that the kininogen in traumatized cord comigrates with 68K low-molecular-weight kininogen or T-kininogen. Trypsin treatment of the kininogen in traumatized cord released both bradykinin and T-kinin, which were separated by HPLC and quantified with a kinin radioimmunoassay. Endogenous kinin levels in the frozen spinal cord also increased up to 40-fold 2 h after injury as compared with controls. The results demonstrate an increased accumulation of kininogen and its conversion to vasoactive kinins in experimental spinal cord injury.
Animals↗
Characterization of Tn5-Induced Mutants of Xenorhabdus nematophilus ATCC 19061.
A negative-selection vector, pHX1, was constructed for use in transposon mutagenesis of Xenorhabdus nematophilus ATCC 19061. pHX1 contains the Bacillus subtilis levansucrase gene which confers sucrose sensitivity. In addition, various Tn5-containing plasmids with different replication origins were transferred by conjugation from Escherichia coli into X. nematophilus ATCC 19061, and one of these plasmids, pGS9, yields Tn5 insertion mutants of X. nematophilus ATCC 19061. By using these two delivery vehicles, more than 250 putative Tn5 insertion mutants of X. nematophilus ATCC 19061 were isolated and were then characterized. Mutants that were altered in bromothymol blue adsorption, ability to lyse sheep erythrocytes, production of antibiotics on a variety of media, and virulence for Galleria mellonella were found.
Journal Article↗
Brain polyphosphoinositide metabolism during focal ischemia in rat cortex.
Using a rat model of stroke, we examined the effects of focal cerebral ischemia on the metabolism of polyphosphoinositides by injecting 32Pi into both the left and right cortices. After equilibration of the label for 2-3 hours, ischemia induced a significant decrease (p less than 0.001) in the concentrations of labeled phosphatidyl 4,5-bisphosphates (66-78%) and phosphatidylinositol 4-phosphate (64-67%) in the right middle cerebral artery cortex of four rats. The phospholipid labeling pattern in the left middle cerebral artery cortex, which sustained only mild ischemia and no permanent tissue damage, was not different from that of two sham-operated controls. However, when 32Pi was injected 1 hour after the ischemic insult, there was a significant decrease (p less than 0.01) in the incorporation of label into the phospholipids in both cortices of four ischemic rats compared with four sham-operated controls. Furthermore, differences in the phospholipid labeling pattern were observed in the left cortex compared with the sham-operated controls. The change in labeling pattern was attributed to the partial reduction in blood flow following ligation of the common carotid arteries. We provide a sensitive procedure for probing the effects of focal cerebral ischemia on the polyphosphoinositide signaling pathway in the brain, which may play an important role in the pathogenesis of tissue injury.
Animals↗
Changes in Schultz-Dale reaction in sensitized canine tracheal smooth muscle.
Tracheal smooth muscles from adult dogs 17 to 20 months of age sensitized with ragweed pollen demonstrated a Schultz-Dale phenomenon in response to specific antigen challenge. Seventy percent of the sensitized tracheal smooth muscles developed a Schultz-Dale reaction that consisted only of a phasic response, and the remaining 30% developed a Schultz-Dale reaction that consisted of a phasic component followed by a discrete tonic component. All the Schultz-Dale reactions were mediated only by histamine. The triggering of presynaptic acetylcholine release by histamine during the Schultz-Dale reaction from tracheal smooth muscles of ragweed-pollen-sensitized puppies 6 to 8 months of age was not detected in sensitized adult dogs. Hyperresponsiveness to acetylcholine was detected in tissues from sensitized puppies but not from sensitized adult dogs. Maximal active tension obtained from the sensitized adult canine trachealis during the Schultz-Dale reaction was lower than that obtained from trachealis from sensitized puppies. Dose-response studies showed that sensitized tissues used in the present studies were hyperresponsive to histamine when compared with their nonsensitized control littermates. These results suggest that the nature of the Schultz-Dale response and the identity of the transmitters is age-dependent.
Acetylcholine↗
Airway smooth muscle mechanics and biochemistry in experimental asthma.
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Animals↗
[Induced differentiation of mouse embryonic stem cells by retinoic acid and dibutyryl cyclic adenosine monophosphate].
In vitro induced differentiation of mouse embryonic stem cells (ES-5 cells), derived from 5-day 129 mouse blastocyst was studied with retinoic acid (RA) and dibutyryl cyclic adenosine monophosphate (dB-cAMP). RA only or RA with dBcAMP together can both induce monolayer ES-5 cells to differentiate into cells of two types: neuron-like cells and fibroblast-like cells. After treated with 10(-6)mol/L RA for 6 days, the differentiated cells were about 80% of all cells, among which most cells were fibroblast-like cells and others were neuron-like cells. While after 6 days of treatment with 10(-6)mol/L RA and 1 mmol/L dBcAMP, the ratio of differentiated cells can be up to 90-95%, and most cells (about 90-95% of differentiated cells) are neuron-like cells. Immunocytochemical analysis of phenotypic markers, especially GFAP and laminin, showed that the neuron-like cells were glia cells. DBcAMP affected the direction and efficiency of induction by RA. The induced differentiation by RA on attached aggregated ES-5 cells was studied as well. In this case, more cell types appeared, such as epitheloid cells, fibroblast-like cells and spindle shaped cells and so on. The exact nature of these differentiated cells was not identified. After attached culture for about 15 days, rhythmically contracting cardiac-like muscle cells were most attractive among those several differentiated cell types. The change of phenotypic markers during induced differentiation of ES-5 cells in monolayer and aggregated state was summarized in table 1. Transforming growth factor-beta 1 (TGF-beta 1) was also examined in undifferentiated and differentiated cells. Untreated ES-5 cells showed positive immunofluorescent reaction to TGF-beta 1 and various differentiated cells showed different reactions. Glia cells and cardiac-like cells displayed a much stronger TGF-beta 1 reaction. These results indicate that the exact role played by TGF-beta 1 during induced differentiation needs further investigation. The different effect of RA on monolayer and aggregated ES cells and the possible significance of cell to cell interaction in the latter case are discussed.
Animals↗
[Scavenging effects of dimercaptosuccinic acid per os on nickel in mice and rats].
In mice and rats given iv or im 63NiCl2 148-370 kBq, radioactivity was present in highest concentrations in kidney, lung, and liver. After given ig dimercaptosuccinic acid (DMSA) 1 g.kg-1, radioactivity decreased remarkably in kidney, lung, and blood. The excretion of 63Ni via urine and feces within 24 h, respectively 13.0 +/- 2.4% and 0.6 +/- 0.4%, was similar to that in the control group in mice. But radioactivity increased markedly in bone. The Ni content of bone decreased on d 7. In rats given im 63NiCl2 370 kBq, two different nickel complex peaks appeared in the gel chromatograms of serum, kidney, and lung. DMSA reduced the contents of protein-bound Ni in serum, kidney, and lung. The results showed that DMSA detoxified the Ni by forming a low toxicity Ni-DMSA complex to redistribute in the body.
Animals↗
A study on the catalytic performance of lipase in reverse micelles.
The hydrolysis of olive oil catalyzed by Candida rugosa lipase solubilized in "H2O/AOT/isooctane" reverse micellar solution has been studied. The optimal conditions observed for lipase in reverse micelles were t = 25 degrees C, pH = 7.9, and R = [H2O]/[AOT] = 10. Lipase in reverse micelles is found to be quite stable. For example, after being incubated at 33 degrees C for 12 hours in AOT/isooctane with R = 5.4, the residual activity of lipase remains as high as 89%. No inhibition was observed even though the substrate concentration was increased up to 50% (v/v), and it was inhibited slightly when 40 mM Cu2+, Co2+ or Mn2+ ions were in the water pools.
Candida↗