Biomedical subjects

Qian Lin

Publications and source records attributed to Qian Lin.

23 records · Page 2Linked to original sources

PubMed2003

Design and synthesis of poly(ADP-ribose) polymerase-1 (PARP-1) inhibitors. Part 4: biological evaluation of imidazobenzodiazepines as potent PARP-1 inhibitors for treatment of ischemic injuries.

A class of poly(ADP-ribose) polymerase (PARP-1) inhibitors, the imidazobenzodiazepines, are presented in this text. Several derivatives were designed and synthesized with ionizable groups (i.e., tertiary amines) in order to promote the desired pharmaceutical characteristics for administration in ischemic injury. Within this series, several compounds have excellent in vitro potency and our computational models accurately justify the structure-activity relationships (SARs) and highlight essential hydrogen bonding residues and hydrophobic pockets within the catalytic domain of PARP-1. Administration of these compounds (5q, 17a and 17e) in the mouse model of streptozotocin-induced diabetes results in maintainance of glucose levels. Furthermore, one such inhibitor (5g, IC(50)=26 nM) demonstrated significant reduction of infarct volume in the rat model of permanent focal cerebral ischemia.

Animals↗

PubMed2003

Post-treatment with a novel PARG inhibitor reduces infarct in cerebral ischemia in the rat.

Poly(ADP-ribose) is synthesized from nicotinamide adenine dinucleotide (NAD(+)) by poly(ADP-ribose) polymerase (PARP) and degraded by poly(ADP-ribose) glycohydrolase (PARG). Overactivation of the poly(ADP-ribose) pathway increases nicotinamide and decreases cellular NAD(+)/ATP, which leads to cell death. Blocking poly(ADP-ribose) metabolism by inactivating PARP has been shown to reduce ischemia injury. We investigated whether disrupting the poly(ADP-ribose) cycle by PARG inhibition could achieve similar protection. We demonstrate that either pre- or post-ischemia treatment with 40 mg/kg of N-bis-(3-phenyl-propyl)9-oxo-fluorene-2,7-diamide, a novel PARG inhibitor, significantly reduces brain infarct volumes by 40-53% in a rat model of focal cerebral ischemia. Our result provides the first evidence that PARG inhibitors can ameliorate ischemic brain damage in vivo, in support of PARG as a new therapeutic target for treating ischemia injury.

Animals↗

PubMed2003

Design and synthesis of poly ADP-ribose polymerase-1 inhibitors. 2. Biological evaluation of aza-5[H]-phenanthridin-6-ones as potent, aqueous-soluble compounds for the treatment of ischemic injuries.

A series of aza-5[H]-phenanthridin-6-ones were synthesized and evaluated as inhibitors of poly ADP-ribose polymerase-1 (PARP-1). Inhibitory potency of the unsubstituted aza-5[H]-phenanthridin-6-ones (i.e., benzonaphthyridones) was dependent on the position of the nitrogen atom within the core structure. The A ring nitrogen analogues (7-, 8-, and 10-aza-5[H]-phenanthridin-6-ones) were an order of magnitude less potent than C ring nitrogen analogues (1-, 2-, 3-, and 4-aza-5[H]-phenanthridin-6-ones). Preliminary stroke results from 1- and 2-aza-5[H]-phenanthridin-6-one prompted structure-activity relationships to be established for several 2- and 3-substituted 1-aza-5[H]-phenanthridin-6-ones. The 2-substituted 1-aza-5[H]-phenanthridin-6-ones were designed to improve the solubility and pharmacokinetic profiles for this series of PARP-1 inhibitors. Most importantly, three compounds from this series demonstrated statistically significant protective effects in rat models of stroke and heart ischemia.

Animals↗

PubMed2003

[Hearing screening of 10,501 newborns].

OBJECTIVE: To investigate the results of hearing screening in newborns so as to explore the appropriate clinical strategy of hearing screening among newborns. METHODS: Transiently evoked otoacoustic emission (TEOAE) was used to examine the hearing of 10,501 newborns 2 - 4 days after birth. Those who failed the initial screening underwent secondary screening with TEOAE. Acoustic brain-stem response (ABR) and 40 Hz AERP were used to monitor the hearing of those who failed the secondary screening every 6 months since the age of 3 months to the age of 3 years. RESULTS: The false-positive rate was 14.92% in the initial screening, and was 0.26% after the 2-stage screening. 62 infants were diagnosed with hearing loss with a prevalence of congenital hearing loss (in one ear or two ears) of 5.90 per thousand and a prevalence of bilateral hearing loss of 2.76 per thousand. CONCLUSION: Hearing screening in the procedure with TEOAE, ABR and 40 Hz AERP helps identify infants with hearing loss as early as possible so as to conduct appropriate intervention.

China↗

PubMed2002

A clinical and experimental study on the protective effects of jiangzhi tongmai fang on endothelial injury.

31 cases of atherosclerosis (AS) were treated with Jiang Zhi Tong Mai Fang ([symbol: see text], formula of JZTMF), and its effect was compared with 30 cases treated with lovastatin in the control group. Clinically, the JZTMF formula showed an effect of regulating blood lipids, and therefore it was antiatherosclerotic. The mechanism is, probably, restoration of the function of endothelial cells (EC) by increasing the synthesis of 6-keto-PGF1 alpha and decreasing the release of endothelin (ET) as evidenced in the experimental study.

6-Ketoprostaglandin F1 alpha↗