Poor outcomes have been reported in African Americans and Hispanics compared to Caucasians with lupus nephritis. The purpose of this retrospective analysis was to identify independent predictors of outcomes in African Americans and Hispanics with lupus nephritis. In total, 93 African Americans, 100 Hispanics, and 20 Caucasians with a mean age of 28 +/- 13 years and an annual household income of 32.9 +/- 17.3 (in 1000 US dollars) were studied. World Health Organization (WHO) lupus nephritis classes II, III, IV, and V were seen in 9, 13, 52, and 26%, respectively. Important baseline differences were higher mean arterial pressure (MAP) in African Americans compared to Hispanics and Caucasians (107 +/- 19, 102 +/- 15, and 99 +/- 13 mmHg, P < 0.05), and higher serum creatinine (1.66 +/- 1.3, 1.25 +/- 1.0, and 1.31 +/- 1.0 mg/dl, P < 0.025). African Americans had lower hematocrit compared to Hispanics and Caucasians (29 +/- 5, and 31 +/- 6, and 32 +/- 7%, P < 0.05), and lower annual household income (30.8 +/- 14.9, 33.1 +/- 15.9, and 42.2 +/- 29.3 in 1000 US dollars; P < 0.05). Lower prevalence of WHO class IV was seen in Caucasians (30%) compared to Hispanics (57%, P = 0.03) and African Americans (51%, P = 0.09). Development of doubling creatinine or end-stage renal disease was higher in African Americans and Hispanics than in Caucasians (31, 18, and 10%; P < 0.05), as was the development of renal events or death (34, 20, and 10%; P < 0.025). Our results suggest that both biological factors indicating an aggressive disease and low household income are common in African Americans and Hispanics with lupus nephritis, and outcomes in these groups are worse than in Caucasians.

No abstract

Several novel analogues of tacrine have been synthesized and tested for their ability to inhibit acetylcholinesterase, butyrylcholinesterase, and neuronal uptake of 5-HT (serotonin) and noradrenaline. Changes in the size of the carbocyclic ring of tacrine produced modest potency against cholinesterase enzymes. Addition of a fourth ring resulted in compounds with marked selectivity for acetylcholinesterase (AChE) over butyrylcholinesterase (BChE): e.g. 6-amino-4,5-benzo-5H-cyclopenta[1,2-b]-quinoline (14a) had an IC50 of 0.35 microM against AChE and 3.1 microM against BChE. Some tetracyclic compounds are 100-400 times more active than tacrine as inhibitors of neuronal uptake of serotonin, in particular 13-amino-6,7-dihydro-5H-benzo-[3,4]cyclohepta[1,2-b]quinoline (18), which had an IC50 of 20 nM. These compounds would be expected to facilitate both cholinergic and monoaminergic transmission. They should be worth investigating in models of memory impairment.

A new potassium channel toxin, HmK, has been isolated from the sea anemone Heteractis magnifica. It inhibits the binding of [125I]-alpha-dendrotoxin (a ligand for voltage-gated K channels) to rat brain synaptosomal membranes with a Ki of about 1 nM, blocks K+ currents through Kv 1.2 channels expressed in a mammalian cell line, and facilitates acetylcholine release at the avian neuromuscular junction. HmK comprises of 35 amino acids (Mr 4055) with the sequence R1TCKDLIPVS10ECTDIRCRTS20MKYRLNLCRK30TCGSC35. A full assignment of the disulfide linkages was made by using partial reduction with tri(2-carboxyethyl)phosphine (TCEP) at acid pH and rapid alkylation with iodoacetamide. The disulfide bridges were identified as Cys3-Cys35, Cys12-Cys28, and Cys17-Cys32. A cDNA clone encoding HmK was isolated using RT-PCR from the total RNA obtained from sea anemone tentacles, while the 5'- and 3'-flanking regions of the cDNA were amplified by RACE. The full-length cDNA was 563 bp long and contained a sequence encoding a signal peptide of 39 amino acids. The coding region for matured HmK toxin was cloned and expressed as a glutathione S-transferase (GST) fusion product in the cytoplasm of Escherichia coli. After affinity purification and cleavage, the recombinant toxin was shown to be identical to native HmK in its N-terminal sequence, chromatographic behavior, and binding to dendrotoxin binding sites on rat brain membranes.