Gap junction intercellular communication and benzene toxicity.

Aberrant regulation of gap junction intercellular communication (GJIC) has been linked to several human diseases, including cancer and abnormal hematopoietic development. Benzene exposure has been shown to cause hematotoxicity and leukemia, but the underlying mechanisms involved remain unclear. We have observed that several metabolites of benzene have the ability to block gap junction intercellular communication.

Benzene metabolites block gap junction intercellular communication. Role in hematotoxicity and leukemia?

A metabolite of benzene, trans,trans-muconaldehyde (MUC) was found to be a strong inhibitor of gap junction intercellular communication (GJIC) with potency similar to that of chlordane. Hydroquinone and the MUC metabolite OH-M-CHO were also strong inhibitors of GJIC. The other MUC metabolites tested, CHO-M-COOH and OH-M-COOH had weak effects on GJIC, while COOH-M-COOH had no effect.

Metabolites of benzene are potent inhibitors of gap-junction intercellular communication.

Chronic exposure to benzene has been shown to lead to bone marrow depression and the development of leukemia. The mechanism underlying the carcinogenicity of benzene is unknown, although a number of genetic changes including chromosomal aberrations have been associated with benzene toxicity. Metabolism of benzene is required for the induced toxicological effects.

Association of lipid peroxidation with antenatal betamethasone and oxygen radial disorders in preterm infants.

Introduction: Premature infants are highly susceptible to 'oxygen radical diseases' (ORD), including bronchopulmonary dysplasia, intraventricular hemorrhage/white matter injury, retinopathy of prematurity, and necrotizing enterocolitis. The incidence of ORD is reduced following antenatal treatment with betamethasone. Oxidant-mediated injury is characterized at the cellular level by peroxidation of lipid membranes.

Use of stable isotopically labeled benzene to evaluate environmental exposures.

The use of stable, isotopically labeled compounds in controlled exposure experiments at environmentally relevant levels allows for the distinguishing of urinary metabolites associated with known exposure from background levels generally present in the urine. Exposures of volunteers to (13)C-benzene for 2 h at 40+/-10 p.p.

Association of lipid peroxidation with hepatocellular injury in preterm infants.

Introduction: We wished to determine whether cholestasis induced by total parenteral nutrition (TPN) in preterm newborn infants is associated with increased oxidative stress secondary to increased reactive oxygen intermediates. We hypothesized that elevated urinary thiobarbituric-acid-reacting substances (TBARS), a marker of oxidative stress, would be associated with hepatocellular injury as measured by serum alanine transaminase (ALT) and aspartate transaminase (AST) levels.

Materials And Methods: Preterm infants (<35 weeks' gestation) admitted to the neonatal intensive care unit were enrolled (with their parents' informed consent) in either the 'cholestasis' group (if their direct bilirubin was >2 mg/dl [34.