Urinary 1-hydroxypyrene as a biomarker of polycyclic aromatic hydrocarbons exposure of workers on a contaminated site: influence of exposure conditions.

The aim of the study was to determine the exposure levels of workers to polycyclic aromatic hydrocarbons on gasworks sites by the measurement of urinary 1-hydroxypyrene. Start-shift and end-shift urine samples were taken every day during an entire week (Monday to Friday), once in November and a second time in June. Four groups of workers were selected according to their activity. Increased exposure was only found among volunteers involved in the remediation of a site, 0.16 to 2.31 mumol/mol creatinine in non-smokers. The median of the non-smoker referent group was 0.02 mumol/mol creatinine (95% confidence interval, 0.01 to 0.04). Smokers had greater exposure levels than non-smokers in every group. Within and between variability was around 200%. Assessment of the exposure of persons on contaminated soil is possible, with the condition that the exposed subjects come in direct contact with the soil.

Infection and the epidural space: a case report.

An epidural infection is a rare and extremely dangerous complication of epidural anesthesia. This case report describes an epidural infection following the use of a continuous lumbar epidural anesthetic. This patient was fortunate, in that the infection did not result in neurologic sequelae and required only long-term intravenous antibiotic therapy. With the increasing use of epidural analgesia and anesthesia, it is important that anesthetists are aware of such a complication in this commonly used technique. This article will review the incidence, pathophysiology, symptomatology, diagnosis, and treatment of epidural infections. Factors relating to epidural infections (equipment use, fever, septicemia and viremia, and duration of catheterization) are also discussed.

Laryngospasm-induced pulmonary edema.

Laryngospasm is one of the more common forms of airway obstruction encountered by an anesthetist. Therapy usually is straightforward, with resolution of the obstruction normally occurring within minutes. In some cases, however, the patient's vigorous inspiratory efforts may lead to a rapidly deteriorating form of pulmonary edema. Two cases are presented that are quite typical of the development of this complication. The etiology, recognition and management of this form of non-cardiac pulmonary edema is discussed.

Pediatric day-care surgery: a 30-year hospital experience.

Over a 30-year period (may 1955 to December 1985), day care surgery was performed on 39,654 patients at the Winnipeg Children's Hospital (WCH). Up to 51% of all pediatric surgical cases and 59% of elective pediatric cases, involving more than 50 different procedures, were performed annually on a day-care basis. The overall incidence of postoperative problems and admission to hospital was 1.5% and 1.1%, respectively. A unique preoperative home visiting program by nurses was demonstrably effective in reducing late cancellations by 75%. The WCH experience adds further evidence that day-care surgery in a pediatric hospital is safe and effective for a large proportion of infants and children requiring operation.

Effects of a viral laryngotracheitis on the epithelial barrier of chicken airways.

The effects of a virus infection on the barrier function of tracheal epithelium were compared to the effects of a chemical agent (methacholine) which selectively increases membrane permeability, and both were compared to controls. The disruption of the airway epithelium induced by the virus infection caused an increased permeation of horseradish peroxidase (HRP) through this barrier. Methacholine enhanced HRP uptake from the airway lumen to the blood as compared to controls. Visualization of HRP in the tracheal epithelium by transmission electron microscopy correlated with the radioimmunoassay measurements in the blood. Serial anti-HRP antibody titers were measured by a competitive binding technique. The antigen permeation induced by methacholine was associated with an enhanced anti-HRP antibody production. The larger increase in antigen permeation seen with the viral infection was associated with depressed anti-HRP titers. It was concluded that viral disruption of the airway epithelial barrier may contribute to an increased uptake of orally inhaled antigens. The relationship, however, between the increased antigen penetration consequent to the viral infection and the development of allergy remains unclear.

The innervation of smooth muscle in the primary bronchus of the chicken.

The innervation of the primary bronchus of the chicken was studied with in vitro pharmacological techniques and with the electron microscope. The primary response of the smooth muscle to field stimulation is relaxation of the muscle and this is not blocked by adrenergic blocking agents. Excitatory cholinergic innervation can be demonstrated when the muscle is partially relaxed. Examination of the ultrastructure of the muscle and nerves shows numerous axon profiles filled with large granular vesicles of the type associated with nonadrenergic or purinergic neurotransmission. Agranular vesicles characteristic of cholinergic innervation are also seen but there is no evidence of adrenergic innervation to the smooth muscle. The smooth muscle cells show connections of the nexus type. These findings indicate that the primary bronchus of the chicken has a dominant inhibitory system and this is nonadrenergic in type.

Neuromuscular structure and function in the airways.

The smooth muscle and the neural pathways of the airways have many similarities to the muscle and innervation of the gastrointestinal tract, as expected from their common embryological origin. The smooth muscle and its innervation vary in structure and function from species to species and extrapolation from one species to another may not be valid. In the human trachea and main stem bronchi the smooth muscle has numerous cell-to-cell connections of the nexus or gap junction type. The principal nervous pathways in the human airways are excitatory, which is cholinergic, and inhibitory, which is nonadrenergic or purinergic. Adrenergic nerves have not been demonstrated in the smooth muscle, but may be present in the ganglions that are found around the trachea and bronchi. Possible defects in the innervation may lead to alterations in the intrinsic activity, of the smooth muscle and be responsible for certain reactive states of the smooth muscle.

A simple technique for the utilization of postmortem tracheal and bronchial tissues for ultrastructural studies.

Human tracheal and bronchial tissues were taken from autopsy cases within five hours of death. The tissue was placed in a modified Krebs-Henseleit solution at either 37 degrees C. or 7 degrees C. A combination of 95 per cent oxygen and 5 per cent carbon dioxide was bubbled through the Krebs-Henseleit solution. Two hours after equilibration of the tissue in the bath at 37 degrees C. and electrical field stimulation was applied to the tissue and, if the tissue was physiologically active, it was utilized for further studies. At the termination of these studies the tissue was processed for electron microscopy. Control tissue was taken directly from the same area as the test tissue and was processed for electron microscopy without immersion in the Krebs-Henseleit solution. The tissue, after immersion in the Krebs-Henseleit solution for at least three hours, showed evidence of substantial recovery from the period of anoxia.

Uptake and transport of exogenous proteins by respiratory epithelium.

The tracer proteins, horseradish peroxidase and ferritin, placed in the trachea of guinea pigs were taken up by epithelial cells and transported to the extracellular space. The interval between the introduction of the tracer proteins into the lumen of the trachea and the morphologic demonstration of the porteins in the extracellular space or within the basal portion of the cells was between 30 and 60 minutes. The proteins were transported in vesicles and no penetration of the epithelial intercellular tight junctions was found. The intercellular tight junctions were made permeable to horseradish peroxidase by anesthetic ether and this permeable epithelium was compared to the vesicle type transport. Transepithelial transport of proteins is a possible mechanism for the introduction of antigenic material into the subepithelial lymphoid tissue and this transport may also be of importance in the late onset type of asthma.

Constrictive pericarditis with dwarfism in two siblings (mulibrey nanism).

Two siblings with marked dwarfism, now 11 and 19 years of age, have been followed from infancy. The girl had frequent episodes of pneumonitis and presented at age 4 years with hepatic enlargement and ascites which proved to be due to constrictive pericarditis. The boy presented with growth failure and pseudohydrocephalus. He had fibrous dysplasia of the tibia and a pathologic fracture; acute hepatic congestion followed physical activity at age 13 years and led to the diagnosis of constrictive pericarditis. Muscle function was normal, there was no evidence for a primary liver disorder, and mental development was normal so that the coined word "mulibray" seemed inappropriate. Pericardiectomy produced only partial improvement; both patients have hepatic enlargement and continue to need diuretics. A third patient with dwarfism, frequent respiratory infections, and pericardial calcification has certain features of the syndrome.

Obstruction of superior vena cava after the Mustard procedure for transposition of the great arteries. Conservative management of chylothorax.

Chylothorax may be produced by superior vena cava (SVC) obstruction, a recognized complication of the Mustard operation for trasposition of the great arteries. The chylothorax may be reduced by keeping the subject in the upright position. Conservative management is an alternative to repeat operation. This syndrome must be recognized, as it can be confused with congestive heart failure. Severe chylothorax may develop insidiously because of progressive SVC obstruction after the immediate postoperative period.