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Biomedical subjects

C S Li

Publications and source records attributed to C S Li.

At least 109 records · Page 6Linked to original sources
PubMed1989

[Pharmacodynamics of dihydroartemisinine against Plasmodium berghei in mice].

Dihydroartemisinine (DHA) is a derivative of qinghaosu(artemisine), which is an antimalarial drug. DHA was given to mice inoculated with Plasmodium berhgei ANKA strain by intramuscular injection. Within proper dose range, the dose-effect and time-effect curves of DHA against the malaria can be described by y = 4.9960 + 2.9536 x and y = 7.2654 - 0.3414 t, respectively, where y is the estimated value of parasitemia suppressing rate in probit; x is log dose; t is the period since drug administration im. Accordingly, the ED50 = 1.00 +/- 0.13 mg/kg and the time of half-effect was 6.6 h, when the dose was 5.0 mg/kg im. The elimination rate constant of the effective dose in vivo was 0.2662h-1 with a half-life of 2.6 h.

Animals↗
PubMed1988

Influence of electrical stimulation of the limbic structure on ovarian steroidogenesis in hypophysectomized and adrenalectomized rats.

The effects of electrical stimulation of the medial amygdala (AMYG) and dorsal hippocampus (DHPC) on the rates of 14C transfer from 14C-1-acetate into ovarian steroids in hypophysectomized and adrenalectomized rats (H-A rats) were investigated. The 14C transfer rates into estrogen were increased by stimulation of AMYG and DHPC. The 14C transfer rates into progesterone and 20 alpha-hydroxy-pregn-4-en-3-one (20 alpha-OH-P) were increased by the AMYG stimulation but decreased by the DHPC stimulation. From these results, it might be suggested that these limbic structures were involved in the regulation of ovarian steroidogenesis without participation of pituitary and adrenal.

17-alpha-Hydroxypregnenolone↗
PubMed1985

Cefuroxime pharmacokinetics in continuous and intermittent peritoneal dialysis.

Pharmacokinetics of cefuroxime was studied in patients on continuous ambulatory or intermittent peritoneal dialysis. A single intravenous bolus (15 mg/kg) of cefuroxime provided a mean serum concentration of 86 mg/litre 5 min, 40 mg/litre 1 h, 163 mg/litre 24 h after the injection. The peritoneal clearance of cefuroxime varied widely among different individuals, ranging from 1.45 to 6.17 ml/min with a mean of 3.59 ml/min during 4-hour exchanges, and from 0,52 to 11.3 ml/min during 2-hour exchanges. A single injection (15 mg/kg) of the antibiotic could not provide satisfactory antibiotic concentrations in peritoneal effluent during peritoneal lavage. When cefuroxime had been added to peritoneal dialysis solution before the solution was instilled into the peritoneal cavity, a significant decrease in cefuroxime concentration occurred in the peritoneal effluent even after a short equilibration time. Furthermore, cefuroxime concentrations measured in residual dialysis solutions in the plastic bags ranged from 44.3 to 1,351% of the concentration of cefuroxime calculated from the added doses, indicating that despite great care, mixing of the antibiotic with dialysis solutions in plastic bags was far from uniform.

Adult↗
PubMed1982

Improved method for determining erythrocyte creatine by the diacetyl-alpha-naphthol reaction: elimination of endogenous glutathione interference.

We describe a simple, accurate, and reproducible method for determining erythrocyte creatine. The method is free from glutathione inhibition and is adaptable to use with standard spectrophotometers as well as centrifugal analyzers. A clear filtrate, essentially free of protein, hemoglobin, and glutathione, is prepared from 0.1 mL of packed erythrocytes by treatment with Ba(OH)2 and ZnSO4, then reacted with diacetyl-alpha-naphthol. The standard curve for this method is linear from 10 to 500 mg/L. We show that endogenous sulfhydryl species such as erythrocyte glutathione will interfere with the creatine-diacetyl-alpha-naphthol reaction. This observation confirmed a suspicion of underestimation of erythrocyte creatine by the method of Griffiths (Clin. Chim. Acta 9: 210, 1964). Added p-chloromercuribenzoic acid did not completely eliminate this inhibition. In the present method these interfering sulfhydryl species are eliminated from the reaction mixture, thus obviating the need for p-chloromercuribenzoic acid and dialysis. The reference interval for this method is 42-80 mg/L.

Creatine↗
PubMed1979

Multiple Y-V plasty.

Webs and contracture, whether congenital or the result of trauma or surgical excision, have been resurfaced with local tissue utilizing the principle of multiple Y-V advancement flaps. Initially the procedure was used in releasing broad scar contracture following a burn wound of the torso, and for congenital soft tissue shortening of the dorsum of the foot, both with gratifying results. The procedure was later used to obtain adjacent soft tissue for resurfacing defects of the nasal tip or ala, resulting from trauma and following the excision of a tumor. (For example, it enabled us to compensate for a rotation flap defect.) It is also useful for additional release of scar contractures of the digits and extremities after transposition of Z-plasty flaps, which can be further advanced using the Y-V advancement principle.

Cicatrix↗
PubMedDate not supplied

PCP/NMDA receptor-channel complex and brain development.

Phencyclidine (PCP) acts on a variety of neurotransmitter systems--cholinergic, catechoaminergic, indoleaminergic, and peptidergic--but the dose at which it produces its psychotomimetic effects is lower than the concentration at which it affects these systems. At low doses, PCP interacts primarily with a binding site located within the ionophore associated with the NMDA receptor complex--binding to this site has been used as a biochemical marker for NMDA channel activity. PCP/NMDA receptor-channel complex has been shown to play an important role in brain development but little is known of the neurochemical effects following postnatal administration of NMDA antagonists in rats. In the present study, rats were treated with PCP from Day 5 until Day 15 after birth and binding to the PCP receptor was measured on postnatal Day 21 using [3H]MK-801; MK-801 is a more potent and specific ligand at the PCP receptor than PCP itself. Postnatal PCP administration produced specific alterations in PCP receptor binding in 21-day-old rat forebrain. There was a reduction in the high affinity component of [3H]MK-801 binding under baseline binding conditions. In the presence of both L-glutamate and glycine, [3H]MK-801 binding in PCP-treated rats increased significantly compared to baseline but did not differ from saline-treated controls. These findings suggest that chronic PCP administration in developing rats alter NMDA channel functioning which could have long-term neurobehavioral consequences.

Aging↗