A 90-day subchronic gavage toxicity study in Fischer 344 rats with 3-methylfuran.

A 90-day gavage study was conducted with 0.0, 0.02, 0.

A 28-day gavage toxicity study in Fischer 344 rats with 3-methylfuran.

3-Methylfuran is produced in foods during food processing and preservation techniques that involve heat treatment such as cooking, jarring, canning, and pasteurization. Currently, there are no studies available on the toxicity of 3-methylfuran. We conducted a 28-day gavage toxicity study (7 days per week) using doses of 0.

A 28-day gavage toxicity study in male Fischer 344 rats with 2-methylfuran.

In most thermally treated products, a series of alkylated furan derivatives have been found, in particular 2-substituted alkylfurans such as 2-methylfuran. These methyl analogs are metabolically activated in a similar fashion as the parent furan, yielding highly reactive unsaturated dialdehydes. There is currently limited toxicological data available for 2-methyl furan exposure by any route that makes conducting a risk assessment difficult.

Antibiotic use for treating dental infections in children: a survey of dentists' prescribing practices.

Background: The authors conducted a study to examine the antibiotic prescribing practices of general and pediatric dentists in the management of odontogenic infections in children.

Methods: The authors relied on a cross-sectional study design to assess the antibiotic prescribing practices of general and pediatric dentists in North Carolina. The survey instrument consisted of five clinical case scenarios that included antibiotic-prescribing decisions in a self-administered questionnaire format.

Toxicologic and immunologic effects of perinatal exposure to the brominated diphenyl ether (BDE) mixture DE-71 in the Sprague-Dawley rat.

Brominated diphenyl ethers (BDEs) are persistent environmental contaminants found in human blood, tissues, and milk. To assess the impact of the commercial BDE mixture DE-71 on the developing immune system in relation to hepatic and thyroid changes, adult (F0) rats were exposed to DE-71 by gavage at doses of 0, 0.5, 5, or 25 mg/kg body weight (bw)/d for 21 weeks.

Brominated diphenyl ether (BDE) levels in liver, adipose, and milk from adult and juvenile rats exposed by gavage to the DE-71 technical mixture.

Brominated diphenyl ethers (BDEs) are used as flame retardants in consumer products. Rodent studies indicate that the liver, thyroid, and nervous system of developing animals are targets of BDEs. To explore the relationship between exposure and health in developing animals, BDE accumulation in adult and juvenile rats was examined in conjunction with changes in liver weight and serum thyroxine (T4).

A novel IL-1 family cytokine, IL-33, potently activates human eosinophils.

Background: Eosinophils are likely key cells involved in the pathogenesis of asthma and allergic diseases; however, the mechanisms that regulate eosinophil dynamics and functions in mucosal tissues are incompletely understood. IL-33, which is produced by mucosal cells, is a new member of the IL-1 cytokine family. Mice injected with IL-33 display profound mucosal eosinophilia with associated pathologic changes.

Chronic rhinosinusitis in adults.

There is no consensus on diagnostic criteria for chronic rhinosinusitis. By convention, the symptoms of chronic rhinosinusitis are similar to those of acute rhinosinusitis but last more than 8 weeks. Diagnosis is based on history, physical examination, and computed tomography scan of the sinuses or rhinoscopy.

Further examination of the effects of nitrosylation on Alternaria alternata mycotoxin mutagenicity in vitro.

Previously, Alternaria extract and metabolite mutagenicities+/-nitrosylation were characterized using Ames Salmonella strains TA98 and TA100, which are both reverted at GC sites. To examine other targets for mutation, the metabolites Altertoxin I (ATX I), Altenuene (ALT), Alternariol (AOH), Alternariol monomethyl ether (AME), Tentoxin (TENT), Tenuazonic acid (TA) and Radicinin (RAD) were reexamined+/-nitrosylation, using Ames Salmonella strain TA97, sensitive to frameshift mutations at a run of C's, as well as strains TA102 and TA104, reverted by base pair mutations at AT sites and more sensitive to oxidative damage. ATX I was also assessed for mammalian mutagenicity at the Hprt gene locus in Chinese hamster V79 lung fibroblasts and rat hepatoma H4IIE cells.

Rectus sheath hematoma: review of 126 cases at a single institution.

Rectus sheath hematoma (RSH) is an uncommon condition characterized by abdominal pain and an abdominal wall mass. We reviewed the clinical features, treatment, and outcomes of 126 patients treated for RSH at Mayo Clinic from January 1, 1992, to December 31, 2002. Most patients (64%) were women and the mean +/- SD age was 67.

Mutagenicity of bisphenol A (4,4'-isopropylidenediphenol) in vitro: effects of nitrosylation.

Bisphenol A (4,4'-isopropylidenediphenol) is a common component of polycarbonate plastics and epoxy resins. Since bisphenol A-containing plastics and resins have found uses in food-contact items, its potential migration into foodstuffs and possible health consequences have been the focus of many recent studies. However, the potential mutagenic activation of bisphenol A by nitrosylation has received little attention.

Effects elicited by toxaphene in the cynomolgus monkey (Macaca fascicularis): a pilot study.

Toxaphene, which was added to glycerol/corn oil, was administered at a level of 1 mg/kg body weight/day in gelatin capsules to four healthy young adult cynomolgus (Macaca fascicularis) monkeys for 52 weeks. Four control monkeys ingested capsules containing only glycerol/corn oil. Each group had two males and two females.

Examination of Alternaria alternata mutagenicity and effects of nitrosylation using the Ames Salmonella test.

Molds of the genus Alternaria are common food pathogens responsible for the spoilage of fruits, vegetables, grains, and nuts. Although consumption of Alternaria alternata-contaminated foodstuffs has been implicated in an elevated incidence of esophageal carcinogenesis, the mutagenic potencies of several A. alternata toxins seem unable to account for the levels of activity found using crude mycelial extracts.

Fractional distillation of acid contaminants from sevoflurane.

On two occasions, sevoflurane distributed for clinical practice has been found to be contaminated with compounds thought to include hydrogen fluoride (HF) and silicon tetrafluoride (SiF(4)). Both compounds can produce pulmonary injury. However, injury would require fractional distillation of the compounds during the course of sevoflurane vaporization.

Dosing via gavage or diet for reproduction studies: a pilot study using two fat-soluble compounds-hexachlorobenzene and aroclor 1254.

The choice of a dosing route for in vivo toxicological tests is often dictated by practical constraints. Reproduction studies are particularly challenging in this regard since the determination of no-effect levels and allowable daily intakes from reproduction data encompasses exposure of the dam to the test xenobiotic prior to pregnancy, during gestation and during lactation. The fetus/infant can be exposed to the xenobiotic as well as the dam's metabolic products of the test xenobiotic during gestation and lactation.

Stereoselectivity in glutathione conjugation and amidase-catalyzed hydrolysis of the 2-bromoisovalerylurea enantiomers in the single-pass perfused rat liver.

Stereoselective glutathione conjugation and amidase-catalyzed hydrolysis of [(R)- and (S)-]2-bromoisovalerylurea (BIU), yielding bromoisovaleric acid (BI) and urea, have been observed in the rat in vivo and in isolated rat hepatocytes. The metabolism of enantiomeric (R)- and (S)-BIU was presently examined in the single-pass perfused rat liver with varying input concentrations (8-250 microM). Steady-state hepatic extraction ratios for (R)-BIU (0.

Uptake of a protein-bound polar compound, acetaminophen sulfate, by perfused rat liver.

The hepatocytic entry of acetaminophen sulfate conjugate was examined in the rat liver, perfused with red cells with and without albumin, by use of the multiple-indicator dilution technique. [3H]acetaminophen sulfate was injected into the portal vein in a bolus of blood containing 51Cr-labeled red blood cells (a vascular reference), sucrose (a low-molecular-weight interstitial reference) or 125I-labeled albumin (a high-molecular-weight interstitial reference, included when albumin was present), and the time courses of their outflow into the hepatic venous blood were observed. The [3H]acetaminophen sulfate, which binds partially to albumin, emerged between albumin and sucrose in the presence of albumin, processed the upslope of the sucrose curve and showed a late low-in-magnitude tailing; the precession disappeared in the absence of albumin.

Esterases for enalapril hydrolysis are concentrated in the perihepatic venous region of the rat liver.

Perfusion of substrate via only the hepatic artery with simultaneous substrate-free perfusion of portal vein or hepatic vein [hepatic artery portal vein-hepatic artery hepatic vein] was used to examine the enzymic distribution of carboxylesterases towards the hydrolysis of enalapril to enalaprilat in the perfused rat liver preparation. In this single-pass method, [14C]enalapril was delivered by the hepatic artery at 2 ml/min into the liver, whereas drug-free perfusate entered the portal vein or hepatic vein at 10 ml/min for HAPV and HAHV perfusions, respectively. During steady state, a multiple indicator dose of 51Cr-labeled red blood cells (vascular marker), [58Co]EDTA (interstitial space marker, which behaves similarly to labeled tracer sucrose), and 3H2O was given into the hepatic artery.

Effects of perfusate flow rate on measured blood volume, disse space, intracellular water space, and drug extraction in the perfused rat liver preparation: characterization by the multiple indicator dilution technique.

The effect of hepatic blood flow on the elimination of several highly cleared substrates was studied in the once-through perfused rat liver preparation. A constant and low input concentration of ethanol (2.0 mM), [14C]-phenacetin and [3H]-acetaminophen (0.

Combined hepatic arterial-portal venous and hepatic arterial-hepatic venous perfusions to probe the abundance of drug metabolizing activities: perihepatic venous O-deethylation activity for phenacetin and periportal sulfation activity for acetaminophen in the once-through rat liver preparation.

Although normal-retrograde liver perfusion allows definition of relative distribution patterns of multienzyme systems involved in parallel, competing and sequential metabolic pathways, the technique fails to describe localization patterns for unienzyme systems. A novel method of perfusion, which can describe the relative zonal enrichment of drug metabolizing activity of unienzyme systems in periportal region and in the entire liver, is described. The rat liver was perfused once-through with combined hepatic arterial (2 ml/min/liver-containing drug) and portal or hepatic venous (10 ml/min/liver, without drug) flows [HAPV and HAHV].

Disposition of enalapril in the perfused rat intestine-liver preparation: absorption, metabolism and first-pass effect.

A new procedure, namely the in situ perfused rat intestine-liver preparation, was introduced to examine the roles of the intestine and the liver in the elimination of enalapril, a new angiotensin-converting enzyme inhibitor. The in situ perfused rat intestine preparation was used to determine the rate and extent of enalapril absorption after an-intraduodenal dose. In the former technique, enalapril in blood perfusate (10 ml/min) was delivered via the superior mesenteric artery into the once-through perfused rat intestine-liver preparation, with sampling effected in reservoir, portal vein and hepatic vein.

Kinetics of meperidine N-demethylation in the perfused rat liver preparation.

Meperidine and normeperidine elimination was studied in the once-through perfused rat liver preparation. Biliary excretion of these bases was minimal, and nonlinear metabolism of meperidine (extraction ratio of 1.0 to 0.

Kinetics of procainamide N-acetylation in the rat in vivo and in the perfused rat liver preparation.

The kinetics of procainamide N-acetylation were studied in the rat in vivo and in vitro. For the in vivo studies, first order kinetics for procainamide and N-acetylprocainamide were found among their respective iv doses of 20, 50, and 70 mg/kg, and 10, 20, and 30 mg/kg. The fraction of total body clearance of procainamide that forms N-acetylprocainamide was found to be 0.