Anaphylactoid reactions associated with reuse of hollow-fiber hemodialyzers and ACE inhibitors.

From July 18 through November 27, 1989, 12 anaphylactoid reactions (ARs) occurred in 10 patients at a hemodialysis center in Virginia. One patient required hospitalization; no patients died. ARs occurred within minutes of initiating dialysis and were characterized by peripheral numbness and tingling, laryngeal edema or angioedema, facial or generalized sensation of warmth, and/or nausea or vomiting. All 12 ARs occurred with dialyzers that had been reprocessed with an automated reprocessing system. A cohort study, including all patients undergoing dialysis sessions on the six days when an AR occurred, showed that the patients who experienced ARs were significantly more likely than patients who did not to be treated with angiotensin-converting enzyme (ACE) inhibitors (7/10 vs. 3/33; relative risk = 7.9; 95% confidence interval = 2.5 to 25.2) and to have been exposed to reused dialyzers rather than to new dialyzers (12/70 sessions vs. 0/31; P = 0.016). In those sessions using a reused dialyzer, the mean number of dialyzer uses in case-sessions was significantly higher than for noncase-sessions (10.3 vs. 6.2; P = 0.016). After reuse of dialyzers was discontinued at the center, no further ARs occurred, despite the continued administration of ACE inhibitors. This is the first report of an outbreak of ARs associated exclusively with reused dialyzers. We hypothesize that interactions between a dialyzer that has been repeatedly reprocessed and reused, blood, and additional factors, such as ACE inhibitors, increased the risk of developing ARs.     

The metabolism of cypermethrin in man: differences in urinary metabolite profiles following oral and dermal administration.

1. The pyrethroid insecticide cypermethrin was administered orally to six male volunteers as a single dose of 3.3 mg (cis: trans 1:1) and dermally to six volunteers at a dose of 31 mg/800 cm2 (cis:trans 56:44) as a soya oil-based formulation. Urine samples were collected for up to 5 days and analysed for the metabolites cis and trans 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (DCVA), 3-phenoxybenzoic acid (3PBA) and 3-(4'-hydroxyphenoxy) benzoic acid (4OH3PBA) following an acid hydrolysis procedure. 2. Following oral dosing approx. equal amounts of (cis+trans DCVA) and (3PBA+4OH3PBA) were excreted with peak excretion rates occurring between 8 and 24 h after dosing. The ratio of trans:cis DCVA was on average 2:1. Based on DCVA measurements the amount of cypermethrin absorbed was estimated to be between 27% and 57% (mean 36%) of the administered dose. 3. Peak urinary excretion rates of metabolites occurred between 12 and 36 h after dermal dosing. The amount of metabolites derived from the phenoxybenzyl moiety (3PBA+4OH3PBA) was on average 4 times greater than the amount of (cis+trans DCVA) recovered in urine. The ratio of trans:cis DCVA was, on average 1:1.2. Based on the recovery of the phenoxybenzyl metabolites it is estimated that 0.85-1.8% (mean 1.2%) of the administered cypermethrin was absorbed. 4. These studies demonstrate marked differences in the urinary metabolite profile by the two routes, and provide an improved basis for determining the extent and main route of absorption of cypermethrin under occupational exposure conditions.     

Seatbelt injury causing perforation of the cervical esophagus: a case report and review of the literature

Blunt trauma to the head and neck is a rare cause of cervical esophageal perforation. We report a cervical esophageal perforation caused by compression by a shoulder-harness seatbelt during a high-speed motor vehicle crash. We are not aware of a similar case in the trauma literature.     

Vehicle Effects on in Vitro Percutaneous Absorption Through Rat and Human Skin

We studied the effects of three vehicles (propylene glycol, octanol and ethyl decanoate) with differing polarity on the in vitro percutaneous absorption of three chemicals (fluazifop-butyl, dimethyl phthalate and fomesafen sodium salt) with a range of physico-chemical properties. Absorption rate measurements were made from high vehicle volume (200 µl/cm²) and low vehicle volume (<10 µLl/cm²) applications. For the lipophilic fluazifop-butyl absorption rate was highest from the more polar vehicle propylene glycol, but this effect was only significant under high-volume conditions. There was a variable vehicle effect on absorption of the intermediate chemical dimethyl phthalate. The largest vehicle effect was seen for the more hydrophilic fomesafen sodium salt where absorption was fastest from the least polar vehicle ethyl decanoate. These results support the hypothesis that the absorption process can in part be predicted from a knowledge of solute solubility. Vehicle effects were greater from high volume applications than from those more comparable to occupational exposure conditions.     

Occupational exposure of Sri Lankan tea plantation workers to paraquat.

Absorption of the herbicide paraquat (1,1''-dimethyl-4,4''-bipyridinium) by mixer-loaders and spray operators on a Sri Lankan tea plantation was assessed over five consecutive days of spraying. Beginning on the day before spraying started and continuing for each of the five spraying days and for seven days after the last day of spraying, 24-hour urine samples were collected from each of the workers. Potential dermal exposure was assessed during further applications of paraquat on the day after the last day of urine collection. For this purpose two spraying replicates were conducted that involved the handling or spraying of an amount of paraquat equivalent to the maximum used per day in the assessment of absorption. The mixer-loaders and spray operators incurred, on average, approximately equivalent amounts of potential dermal exposure (66 mg and 74 mg paraquat ion, resp.); however, the distribution of the exposure differed. About 86% of the total exposure experienced by the mixer-loaders was to the hands, whereas about 90% of the exposure of the spray operators involved their hands, legs, and feet, in approximately equal proportions. In both cases, 90% or more of the total potential exposure involved parts of the body that were normally uncovered. Despite the evidence of dermal exposure, no paraquat was detected in the workers'' urine. This probably was due to the very low concentration of paraquat in the solutions used for spot spraying on tea plantations (0.3-0.4 g paraquat ion per litre), the high standard of personal hygiene exercised by the workers, and the low permeability of human skin to paraquat.