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Biomedical subjects

B Johnson

Publications and source records attributed to B Johnson.

At least 451 records · Page 25Linked to original sources
PubMedDate not supplied

Widespread arsenic contamination of soils in residential areas and public spaces: an emerging regulatory or medical crisis?

A critical review finds government agencies allow, permit, license, or ignore arsenic releases to surface soils. Release rates are controlled or evaluated using risk-based soil contaminant numerical limits employing standardized risk algorithms, chemical-specific and default input values. United States arsenic residential soil limits, approximately 0.4- approximately 40 ppm, generally correspond to a one-in-one-million to a one-in-ten-thousand incremental cancer risk range via ingestion of or direct contact with contaminated residential soils. Background arsenic surface soil levels often exceed applicable limits. Arsenic releases to surface soils (via, e.g., air emissions, waste recycling, soil amendments, direct pesticide application, and chromated copper arsenic (CCA)-treated wood) can result in greatly elevated arsenic levels, sometimes one to two orders of magnitude greater than applicable numerical limits. CCA-treated wood, a heavily used infrastructure material at residences and public spaces, can release sufficient arsenic to result in surface soil concentrations that exceed numerical limits by one or two orders of magnitude. Although significant exceedence of arsenic surface soil numerical limits would normally result in regulatory actions at industrial or hazardous waste sites, no such pattern is seen at residential and public spaces. Given the current risk assessment paradigm, measured or expected elevated surface soil arsenic levels at residential and public spaces suggest that a regulatory health crisis of sizeable magnitude is imminent. In contrast, available literature and a survey of government agencies conducted for this paper finds no verified cases of human morbidity or mortality resulting from exposure to elevated levels of arsenic in surface soils. This concomitance of an emerging regulatory health crisis in the absence of a medical crisis is arguably partly attributable to inadequate government and private party attention to the issue.

Animals↗
PubMedDate not supplied

Rehabilitative considerations for patients with severe Stevens-Johnson syndrome or toxic epidermal necrolysis. A case report.

Stevens-Johnson syndrome and toxic epidermal necrolysis are dermatologic disorders that demonstrate pathophysiologic similarities to partial-thickness burn injury and benefit from treatment in a multidisciplinary burn center. Although burn therapists frequently participate in the care of these patients, guidelines for rehabilitative intervention have not been previously identified. A case report highlights the potential rehabilitative complications and treatment interventions indicated for patients with severe forms of these conditions.

Child↗
PubMedDate not supplied

Expression of Fc gamma binding sites on human extraplacental membranes.

Binding sites for the Fc portion of immunoglobulin G (IgG) molecules (Fc gamma BS) were identified on amnionic epithelial cells and chorionic trophoblast cells in human extraplacental membranes using direct immunofluorescence with labeled human IgG. The binding sites are similar to FC gamma BS on placental trophoblast in their specificity and high degree of relative binding affinity for IgG monomers. Neither immunoglobulin A (IgA) nor IgM bound to a significant degree to the membranes. Binding was completely inhibited with unlabeled IgG but not F(ab')2 fragments of IgG. Studies on isolated amnion cells demonstrated that the binding sites are expressed on the cell membrane. At the level of sensitivity of the immunohistologic methods used, aggregated IgG or antigen-antibody complexes failed to bind amnionic epithelial cells or chorionic trophoblasts. This is in contrast to Fc gamma BS on macrophages which, being present in the same tissue, failed to exhibit significant binding of deaggregated IgG but bound complexes avidly.

Amnion↗
PubMedDate not supplied

Closing of a psychiatric intensive care unit: a manifestation of lost values.

TOPIC: A psychiatric intensive care unit shown to be of value to patients and staff was closed within a year, ostensibly for economic reasons. PURPOSE: To examine the usefulness of psychiatric intensive care units, and the importance of thinking through the ramifications of downsizing SOURCE: A case study of a psychiatric ICU in Northern Ontario, Canada and a review of the literature. CONCLUSIONS: When downsizing is considered, a careful examination of values must take place, remembering patient care comes first.

Cost Control↗
PubMedDate not supplied

Experiences with implantable hearing devices and a presentation of a new device.

Following animal experiments, anatomic examinations, and histologic studies, an implantable hearing device was developed. This device, the temporal bone stimulator (TBS), uses an inductive coil without percutaneous connection that transmits bone-conducted vibrations to the inner ear. Ten patients have been implanted and followed by the Central Ear Research Institute. The TBS is effective and may have wide application in producing amplification in good sound fidelity when used in patients who have external canal, middle ear, or eustachian tube disease that is poorly corrected by surgery or conventional hearing aids. The utilization of similar principles of electromagnetic transfer of energy directly to the ossicles appears reasonable and is potentially highly rewarding for those who have sensorineural hearing impairments with thresholds greater than 40 dB. The enormous potential benefits derived from the application of these implantable hearing devices is worthy of the greatest effort in future otologic investigation.

Animals↗
PubMedDate not supplied

Implantable bone conduction hearing device: Audiant bone conductor. Update on our experiences.

An implantable hearing device has been developed and has undergone testing by animal experimentation and clinical trials in humans. Recently, the Food and Drug Administration has approved the use of this device in adults who are within the criteria of its utilization, mainly patients with conductive hearing impairments who have good inner ear reception and who are unable to benefit from surgical correction. This update describes observations and experiences we have had during the device's development and defines its limitations as well as its unique thrust into the future relief of hearing impairment. Clinical trials during the investigational period and engineering problems as well as progress are thoroughly discussed.

Adolescent↗
PubMedDate not supplied

Trustee insights on business and health care.

Many hospital board members are active business people in their communities and are sensitive to and aware of increasingly difficult problems both hospitals and business face. This article summarizes two focus group discussions held with the members of the MHA Governance Council earlier this year. The Council is comprised of 25 hospital trustees and three hospital executives.

Commerce↗