Biomedical subjects

S Chong

Publications and source records attributed to S Chong.

94 records · Page 6Linked to original sources

PubMedDate not supplied

Neurologic complications of pediatric liver transplantation.

The neurologic complications of 24 children, ages 5 months to 18 years, following orthotopic liver transplantation at the Indiana University hospitals are reported. Biliary atresia (14 patients) was the most common cause for orthotopic liver transplantation. Three children died. Seventeen children (70%) had no neurologic deficit on follow-up 6 months or longer after transplantation. Eleven children (46%), including 4 of 16 patients (25%) who had received OKT3, had neurologic complications. Seven children (29%) had new-onset seizures; 4 of these patients had status epilepticus. Two children had intracranial hemorrhage. Seizures occurred later in children than in adults following orthotopic liver transplantation and were not associated with poor prognosis. Longer term follow-up is indicated to assess subtle, cognitive deficits following liver transplantation in children.

Adolescent↗

PubMedDate not supplied

Current methodologies used for evaluation of intestinal permeability and absorption.

This review article will focus on the various techniques that are currently employed by drug discovery scientists in evaluating permeability/absorption of drug candidates during the drug candidate selection process. Various preclinical methodologies are available; each having advantages and disadvantages, but it is the judicious use of these techniques that can help identify drug candidates that will be well absorbed in humans. It is well recognized that the human intestinal permeability cannot be accurately predicted based on a single methodology (in vitro: tissue/cell culture, in situ, or in vivo).

Animals↗

PubMedDate not supplied

Detection of Chlamydia trachomatis antigens in male urethral swabs and urines with a microparticle enzyme immunoassay.

BACKGROUND AND OBJECTIVES: More information is needed on the natural history of Chlamydia trachomatis urethral infections in men. Newer assays for detecting antigens in male first void urine and urethral swabs identify patients for control programs. A new microparticle enzyme immunoassay from Abbott Laboratories called IMX Select Chlamydia was evaluated and compared with culture and an expanded gold standard for sensitivity and specificity. STUDY DESIGN: Paired samples of first void urine and two urethral swabs were tested from 230 men, 73% of whom had symptoms of urethritis. Both specimen types were tested with IMX Select, the other swab was cultured, and a part of the first void urine was tested by Chlamydiazyme enzyme immunoassay. Performance calculations were made against urethral culture and an expanded gold standard that included direct fluorescent staining of discordant specimens by Microtrak. RESULTS: Compared with urethral swab culture, the IMX Select test performed on urethral swabs and first void urine had sensitivities of 93.8% and 81.3%, and specificities of 95.2% and 95.7%, respectively. Calculations of sensitivity and specificity based on the expanded gold standard were: IMX Select on urethral swabs, 88.5% and 99.4%; IMX Select on first void urine, 80.8% and 100%; Chlamydiazyme after blocking confirmation on first void urine, 73.1% and 100%; culture on urethral swabs, 61.5% and 100%. CONCLUSION: This IMX Select Chlamydia enzyme immunoassay, which generates laboratory results within 2 hours, performed better than culture and an established enzyme immunoassay on male urethral swabs. The experimental first void urine protocol showed promise for noninvasive male testing.

Antigens, Bacterial↗

PubMedDate not supplied

Thiol-mediated catalysis of nitroglycerin degradation by serum proteins. Increase in metabolism was not accompanied by S-nitrosothiol production.

In vitro degradation of nitroglycerin (NTG) in human plasma has been shown to be accelerated significantly by sulfhydryl compounds. The interaction between NTG and N-acetyl-1-cysteine (NAC) in human plasma produces a pharmacologically active S-nitrosothiol, which may be responsible, at least in part, for the in vivo nitrate tolerance-reversing effect of NAC. The mechanism of this thiol-mediated NTG degradation in plasma has not been identified. In this report, we examined the catalytic activity of various plasma proteins toward NAC-mediated NTG degradation and found human serum albumin (HSA) to have the highest catalytic activity among the proteins tested. However, the dinitrate metabolite distribution ratio found with HSA (favoring the 1,3- over the 1,2-isomer) was substantially different from that observed with human plasma (where equal amounts of both dinitrates were produced). In addition, the HSA-catalyzed degradation of NTG did not lead to enhanced formation of S-nitrosothiol. These findings therefore argue against a predominant role exerted by HSA in the thiol-mediated NTG metabolism in plasma. The HSA-mediated catalysis of NTG was partially blocked by pretreatment with NAC followed by a thiol-alkylating agent, suggesting that the catalytic mechanism was due, in part, to the conversion of disulfide linkages within the HSA structure to reactive sulfhydryl groups.

Acetylcysteine↗