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Biomedical subjects

X H Yu

Publications and source records attributed to X H Yu.

26 records · Page 2Linked to original sources
PubMed1989

[Irreversible action of the opioid agonist alpha-CAM and its reaction with SH groups at opioid receptor binding sites].

7 alpha-Bis (beta-chloroethyl)amino-methyl-6,14-endoethenotetrahydrooripavine (alpha-CAM) was found to bind to opioid receptors irreversibly and react directly with sulfhydryl (SH) groups in P2 preparations of rat brain. The P2 preparations were pretreated as follows: protection of the SH groups at the opioid receptor binding sites by morphine or etorphine, and inactivation of the SH groups outside the binding sites by N-ethylmaleimide (NEM), followed by removal of the morphine or etorphine by washing. alpha-CAM was still able to bind the pretreated P2 preparations in an irreversible manner. The results indicate that the formation of covalent bonds between alpha-CAM and the SH groups of opioid receptor binding sites is possibly one of the biochemical mechanisms of the irreversible action of alpha-CAM.

Analgesics↗
PubMed1989

[Pharmacological study on a new irreversible agonist of opioid receptors, 7 alpha-bis(beta-chloroethyl) aminomethyl-6, 14-endoetheno-tetrahydrooripavine].

7 alpha-bis (beta-chloroethyl) aminomethyl-6, 14-endoetheno-tetrahydro oripavine (alpha-CAM) is a new irreversible opioid receptor agonist. Its effect on isolated tissues (guinea pig ileum, mouse vas deferens, rat vas deferens and rabbit vas deferens) were studied. It was shown to be bound irreversibly to rat brain P2 membrane preparations. The ED50 of its analgesic effect in mice (icv) was found to be 0.12 nmol/mouse, and the effect may last as long as 2-3 days. It is a compound which produces the longest analgesia known up to date. A single dose (icv) of alpha-CAM was sufficient to produce dependence in mice. Thus, the compound may serve as an agent for studying the mechanism of physical dependence.

Analgesics↗
PubMed1988

A seroepidemiologic study of hepatitis B virus infection among barbers in Huangshi City, Hubei, China.

Between March and August 1986 in Huangshi City, serum samples were collected from 316 apparently healthy barbers as a study group, as well as from 361 healthy employees of department stores as a control group. They were tested for hepatitis B surface antigen (HBsAg), antibody to HBsAg (anti-HBs) and antibody to hepatitis B core antigen (anti-HBc) by enzyme-linked immunoadsorbent assays. Barbers showed a prevalence higher than that in controls for HBsAg (16.8 vs. 9.2%, P less than 0.01), anti-HBs (67.1 vs. 45.9%, P less than 0.001), and anti-HBc (39.2 vs. 21.2%, P less than 0.001). The prevalence of at least one marker of hepatitis B virus (HBV) infection was significantly higher in barbers than in controls (86.1 vs. 61.7%, P less than 0.001). Although the socioeconomic status and education level did not correlate with the frequency of HBV markers, the prevalence of HBsAg increased in parallel with the duration of practice. Because of their high risk for HBV infection, barbers need to be screened for markers of HBV infection on a routine basis, and are prime candidates for immunoprophylaxis with hepatitis B vaccine.

Adolescent↗