Study of heavy metal poisoning in frequent users of Chinese medicines in Hong Kong and Macau.

This study is a direct assessment of blood heavy metal concentrations of frequent users of Chinese medicines (CM), who had been taking prescribed CM at least 6 days per week for not less than 3 months, to determine whether their intake of CM could cause an increased load of toxic heavy metals in the body. From November 2009 to June 2010, 85 subjects were recruited with informed consent, and their blood samples were collected for measurement of arsenic, cadmium, lead and mercury concentrations. Results showed that blood concentrations of four heavy metals of nearly all 85 subjects were within reference ranges. Only one subject who had consumed plentiful seafood was found to have transiently increased blood arsenic concentration (29% higher than the upper limit of the reference range). However, after refraining from eating seafood for 1 month, his blood arsenic concentration returned to normal. Eighty commonly prescribed CM in both raw medicine and powder concentrate supplied by local distributors were also tested for the four heavy metals. Twelve out of the 80 raw medicines were found to contain one or more of the heavy metals that exceeded the respective maximum permitted content. Cadmium was most frequently found in the contaminated samples. None of the powder concentrates had heavy metal content exceeding their respective maximum permitted level.

Value of long-term administration of acyclovir and similar agents for protecting against AIDS-related lymphoma: case-control and historical cohort studies.

Acyclovir or similar agents with activity against Epstein-Barr virus (EBV) theoretically may prevent non-Hodgkin's lymphoma (NHL) in AIDS. A case-control study of 29 patients with AIDS-related NHL and 58 matched control subjects assessed the frequency with which daily acyclovir (>/=800 mg/d) or similar agents were used for > or =1 year. In a historical cohort of 304 patients with AIDS for > or =2 years, the prevalence of NHL was assessed among 3 groups of patients: those who received long-term treatment with high-dose acyclovir (or similar agents) or low-dose or intermittent acyclovir; those treated with ganciclovir/foscarnet for <1 year; and those who had not previously been treated with acyclovir, ganciclovir, or foscarnet. In the case-control study, 22 patients (72.4%) with NHL never received acyclovir or similar drugs versus 19 control subjects (32.8%; P=. 002); 2 patients (6.9%) with NHL received acyclovir (> or =800 mg/d) for > or =1 year versus 27 (46.6%) of control subjects (P=.0001). In the cohort study, 6 (6.8%) of 88 patients who received acyclovir (> or =800 mg/d) for > or =1 year developed NHL versus 15 (15.5%) of 97 patients who received intermittent or lower-dose acyclovir and 30 (25.2%) of 119 patients who never received these agents (P=.002). Long-term administration (>1 year) of high-dose acyclovir or similar agents with anti-EBV activity may prevent NHL in patients with AIDS. A prospective, randomized study is warranted to confirm these results.

Identification of terminal N-acetylglucosamine residues of highly branched asparagine-linked oligosaccharides as immunoreactive domains of a chicken heterophile antigenic determinant.

Chicken heterophile antigenic determinant (CHAD-1) has been previously found in medullary lymphocytes of the bursa and thymus as well as in some non-lymphoid cells by the immunoperoxidase method, using rabbit antiserum to a complete Freund's adjuvant (CFA) as the first antibody. In this work we demonstrated that absorption of anti-CFA serum with highly purified preparations of hen egg white glycoproteins (ovomucoid, ovoinhibitor, ovalbumin) or chicken orosomucoid completely blocked immunoperoxidase staining for CHAD-1. Treatment of these glycoproteins with beta-N-acetylglucosaminidase suppressed their capacity to inhibit this staining. Absorption of anti-CFA serum with asparagine-linked glycopeptides which have the mannose alpha 1,3 arm disubstituted by GlcNAc residues and which have another GlcNAc residue linked beta 1,4 to the beta-linked mannose of the core also inhibited staining for CHAD-1. These data indicated that highly branched asparagine-linked oligosaccharides with terminal GlcNAc residues beta-linked to mannose represent immunoreactive domains of CHAD-1.