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Biomedical subjects

G Xiao

Publications and source records attributed to G Xiao.

At least 127 records · Page 7Linked to original sources
PubMed1994

[The pharmacokinetics of ceftazidime in the burned patients].

Pharmacokinetic studies were carried out following systemic administration of ceftazidime in ten burn patients (TBSA 30%-60% and with full-thickness burn) and six healthy volunteers. Dynamic ceftazidime concentrations in blood, urine and blister fluid were analysed by HPLC. The results showed that the burned patients, especially during their shock phase, some pharmacokinetics parameters differed from that of normal volunteers, in that the volume of distribution (0.45 +/- 0.06 L/kg vs. 0.23 +/- 0.05 L/kg) and non-renal clearance of drug (30.54 +/- 21.97ml.min-1 vs. 11.08 +/- 4.91 ml.min-1) increased, but the elimination of half-life was prolonged. The result indicated that it was not necessary to increase the dosage of ceftazidime in extensive burns in the early period. Burn blister fluid concentrations were higher than MIC. Ranging from 1.004-21.62 micrograms/ml, indicating that systemic ceftazidime could penetrate second-degree burn tissue in the early postburn stage.

Adolescent↗
PubMed1994

[Prophylactic effect of systemic ceftazidime on bacterial translocation in scalded rats].

In this study, we evaluated the prophylactic effect of Ceftazidime on bacterial translocation (BT) of Pseudomonas aeruginosa in scalded rat by qualitative and quantitative bacterial cultures of blood, organs and mesenteric lymph nodes (MLN). Ceftazidi-me was administered systemically at 3 h, 6 h and 12 h post injury respectively. The dynamic changes in levels of Ceftazidime in blood and organ tissues were also determined. The results showed that effective levels of Ceftazidime in blood, liver and mucosa of the small intestine were rapidly reached and maintained for more than 4 h, but no drug was found in MLN. The prophylactic effect on BT was significant when systemic administration started at 3 h post injury (P < 0.001) and 6 h post injury (P < 0.05). Although the incidence of BT was unchanged (P > 0.05) when systemic administration started at 12 h, the number of organisms present in livers and kidneys, except MLN, was dramatically reduced (P < 0.01).

Animals↗
PubMed1994

[The study of mechanisms and effects of prophylaxis and cure of electroacupuncture against ischemia injury in brain].

In order to observe the influence of electroacupuncturing (EA) "Ren Zhong" point on acute ischemia injury in brain, an experimental model of acute ischemia injury in brain was produced by antidromically blocking double common carotid arteries in 18 rabbits. The basic arteries' pressure will be increased by EA, RA and the contents of AI, A II increased and the content of LA reduced obviously in brain. An experimental evidence was given for the safety of EA anesthesia and the curative effect of EA on ischemia in brain.

Angiotensin II↗
PubMed1993

Structures of 3-hydroxy-1-(2-methoxyethyl)-2-methyl-4-pyridinone, its hydrochloride and 1-ethyl-3-hydroxy-2-methyl-4-pyridinone hydrochloride hydrate.

3-Hydroxy-1-(2-methoxyethyl)-2-methyl-4(1H)-pyridinone (1) exists mainly in the quinoid form with a small contribution from the aromatic zwitterion form, while 3-hydroxy-1-(2-methoxyethyl)-2-methyl-4(1H)-pyridinone hydrochloride (2) and 1-ethyl-3-hydroxy-2-methyl-4(1H)-pyridinone hydrochloride hydrate (3) are observed to occur in the aromatic form with a minor contribution from the quinoid resonance form. Different substituents at the ring N position do not have significant geometric effects in either the neutral molecules, as a group, or in the hydrochloride salts.

Crystallography, X-Ray↗
PubMed1993

Synthesis, physicochemical properties, and biological evaluation of N-substituted 2-alkyl-3-hydroxy-4(1H)-pyridinones: orally active iron chelators with clinical potential.

The synthesis of a range of novel bidentate ligands containing the chelating moiety 3-hydroxy-4(1H)-pyridinone is described. The pKa values of the ligands and the stability constants of their iron(III) complexes have been determined. The crystal structures of one of the ligands and one of the iron(III) complexes are presented. The distribution coefficients of the ligands are reported and are related to the ability of the ligands to remove iron from hepatocytes. The influence of 3-hydroxy-4(1H)-pyridinones on oxidative damage to cells is described. In contrast to the iron chelator in current therapeutic use, desferrioxamine-B, many of the bidentate ligands described in this study are orally active in iron-overloaded mice.

Administration, Oral↗
PubMed1993

3-[1-(Ethylamino)ethylidene]-6-methyl-3H-pyran-2,4-dione.

The structural results clearly indicate that 3-[1-(ethylamino)ethylidene]-6-methyl-3H-pyran-2,4-dione exists as a keto-enamine tautomer in the solid state. The H atom bonded to N(9) refines with a normal temperature factor and the bond distance of the keto group [C(4)--O(13)] of 1.263 (1) A is elongated due to resonance. This resonance is also indicated by an averaging of the single bonds [C(2)--C(3), C(3)--C(4), C(4)--C(5) and C(8)--N(9)] and double bonds [C(3)--C(8) and C(4)--O(13)] in the crystal structure and by the fact that not only is the pyran ring planar [r.m.s. deviation 0.0212 (9) A] but also there is planarity for the whole molecule [r.m.s. deviation 0.074 (1) A]. A strong intramolecular hydrogen bond is found between the 4-oxo group and the amine H atom.

Hydrogen Bonding↗
PubMed1993

Transformation of wheat protoplasts mediated by cationic liposome and regeneration of transgenic plantlets.

E. coli plasmid pCGN1055 containing the hygromycin phosphotransferase (Hpt) gene under the control of the plant promoter was introduced into wheat protoplasts by cationic liposome (lipofectin)-mediated transformation, and transgenic albino plantlets were obtained. The transformation frequencies were 6.0% and 8.8% according to hygromycin resistance and DNA molecular hybridization. The assay of Hpt enzyme activity and Southern blot indicated the foreign gene existed and expressed in transgenic plantlets.

Cations↗
PubMed1993

[Molecular genetic analysis on six cases of sex reversal syndrome].

Southern blot hybridization using Y-specific DNA probes and electrophoretic analysis of the SRY gene fragment amplified through polymerase chain reaction (PCR) have been performed in six cases of sex reversal syndrome (three 46, XX males and three 46, XY females). The result showed that the Y-specific DNA hybridization signal and SRY sequence were absent in one XX male and present in the remaining cases. This finding indicates that testis development of this XX male was initiated in the absence of the SRY gene.

Adult↗