RESUMEN

The presence of hazardous air pollutants (HAPs) entrained in end-use natural gas (NG) is an understudied source of human health risks. We performed trace gas analyses on 185 unburned NG samples collected from 159 unique residential NG stoves across seven geographic regions in California. Our analyses commonly detected 12 HAPs with significant variability across region and gas utility. Mean regional benzene, toluene, ethylbenzene, and total xylenes (BTEX) concentrations in end-use NG ranged from 1.6-25 ppmv─benzene alone was detected in 99% of samples, and mean concentrations ranged from 0.7-12 ppmv (max: 66 ppmv). By applying previously reported NG and methane emission rates throughout California's transmission, storage, and distribution systems, we estimated statewide benzene emissions of 4,200 (95% CI: 1,800-9,700) kg yr-1 that are currently not included in any statewide inventories─equal to the annual benzene emissions from nearly 60,000 light-duty gasoline vehicles. Additionally, we found that NG leakage from stoves and ovens while not in use can result in indoor benzene concentrations that can exceed the California Office of Environmental Health Hazard Assessment 8-h Reference Exposure Level of 0.94 ppbv─benzene concentrations comparable to environmental tobacco smoke. This study supports the need to further improve our understanding of leaked downstream NG as a source of health risk.

Asunto(s)

RESUMEN

Nucleoside triphosphate diphosphohydrolase-1 (NTPDase1/CD39) is the dominant ecto-nucleotidase of vascular and placental trophoblastic tissues and appears to modulate the functional expression of type-2 purinergic (P2) G-protein coupled receptors (GPCRs). Hence, this ectoenzyme could regulate nucleotide-mediated signalling events in placental tissue. This immunohistochemical and immuno-electron microscopic study demonstrates the expression of NTPDase1/CD39, P2Y1 and P2Y2 receptors in different cell types of human placenta. Specifically P2Y1 has an exclusive vascular distribution whereas P2Y2 is localized on trophoblastic villi. Co-localization of P2Y1 and NTPDase1/CD39 are observed in caveolae, membrane microdomains of endothelial cells. The differential localization of these P2 receptors might indicate their unique roles in the regulation of extracellular nucleotide concentrations in human placental tissues and consequent effects on vascular tone and blood fluidity.

Asunto(s)

RESUMEN

This paper deals with the emergence, elaboration, and use of the concept of "the wounded healer." The term refers to a person whose personal experience of illness and/or trauma has left lingering effects on him--in the form of lessons learned that later served him in ministering to other sufferers, or in the form of symptoms or characteristics that usefully influenced his therapeutic endeavors. While such persons and their actions have been noted across the ages, in other cultures, and in many contexts, it was not until the early twentieth century that the patterns in the behaviors of such persons were recognized, named, explained, and categorized as "healing." Early in the century, the concept was commonly used in the fields of pastoral counseling and analytical psychology; by the end of the century it had been vastly expanded and extended and no longer referred mainly to a healer of psychological suffering. The term wounded healer is now in common use in areas such as rehabilitation medicine, medical-career choice, Alcoholics Anonymous and the self-help movement, and chronic-illness support groups, as well as in the original areas of psychotherapy and pastoral care.

Asunto(s)

RESUMEN

Assessment of chemicals for their potential to cause developmental toxicity must include evaluation of the development of the fetal skeleton. The method described here is an improved and fully automated double staining method using alizarin red S to stain bone and alcian blue to stain cartilage. The method was developed on the enclosed Shandon Pathcentre, and the quality of specimens reported here will be reproduced only if carried out on a similar processor under the same environmental conditions. The staining, maceration and clearing process takes approximately 6 days. The personnel time, however, is minimal since solutions are changed automatically and the fetuses are not examined or removed from the processor until the procedure is completed. Upon completion of processing, the bone and cartilage assessment of the specimens can be carried out immediately if required. Full evaluation of skeletal development in both the rat and the rabbit is necessary to meet the requirements of safety assessment studies. This method allows this to be accomplished on a large scale with consistently clear specimens and in a realistic time.

Asunto(s)

RESUMEN

With roots in ancient religious practices of purification and cleansing and in ancient medicine's purgings, Plato evolved a verbal catharsis for diseases of the soul, and Aristotle developed a catharsis of the passions through tragic drama. Through the centuries, most cultures have had recognized contexts in which emotions were evoked, heightened in intensity, and ultimately released or discharged; and cathartic procedures can be detected in many cultures' healing practices. The late decades of the nineteenth century saw the emergence of numerous psychological healings with a cathartic basis. Catharsis came to mean the lively remembering of a traumatic experience in addition to the emotional release; and the term abreaction frequently was used to refer to the emotional release. Subsequently, the notion that the recovered traumatic memories needed to be integrated with the rest of the patient's mental life became a third significant element. The significance of these three factors has been debated vigorously; but, whether it has been some combination of them or merely the emotional discharge, there has been a cathartic element in many twentieth-century approaches to psychological healing.

Asunto(s)

RESUMEN

OBJECTIVE: The purpose of this paper is the assessment of the healer's listening as an aspect of the history of caring and curing, with particular attention to its place in psychological healing. METHOD: An extensive range of philosophical, religious, and medical sources from antiquity to the present were studied. RESULTS: Over the centuries, listening has been a crucial aspect of the various endeavors undertaken by healers in the interest of acquiring information from, achieving understanding of, and bringing about healing effects for sufferers. Yet it has been vision rather than hearing that has been emphasized in knowing and understanding, and looking rather than listening that has been emphasized in healing endeavors. Only around the turn of the twentieth century did there emerge the focused study of care in listening, of listening beyond the words themselves, and of the significance of the interested listener as a soothing, empathic force. CONCLUSIONS: The place of listening in depth and with empathy is a crucial element in healing. While the emphasis on looking remains significant in the gathering and appraisal of data, at times it threatens to overwhelm the need for an attentive and concerned listener. There appears to be a natural tension between the two modes that has, in modern times, been translated into a tension between the two modes that has, in modern times, been translated into a tension between a scientific mode of gaining information and a humanistic mode of knowing sufferers. A healer neglects either one at his or her peril--and at the peril of his or her patients.

Asunto(s)

RESUMEN

As one of the internal senses or inward wits, the imagination was long thought to play a crucial role in the age-old struggle between the rational and the irrational, and it was conceived of as a faculty that might be damaged in some forms of psychopathology. During the Renaissance it emerged as a force or factor with a considerable potential for causing harm in the form of disease and for doing good in the form of curing disease. Its place in psychological healing has been significant for much of the time since then, including a lively attention to it in the work of Carl Jung and in the guided imagery techniques of recent decades.

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

In the medical literature of the eighteenth century melancholia came to be defined as partial insanity. Seventeenth-century English law introduced the term and influenced later forensic concerns about the concept. But the history of melancholia reveals a gradual development of such a concept of limited derangement associated with the delusions usually cited in accounts of this disease. In the early nineteenth century the relationship of melancholia and this concept weakened and was gradually abandoned, the content of the syndrome of melancholia was reduced, and out of this complex process emerged the notion of monomania.

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

A lipopolysaccharide (LPS) fraction was extracted from Nichols, nonpathogenic Treponema pallidum by the hot, phenol-water procedure. The LPS was freed of nucleic acids and water-soluble proteins by successive exposures to ribonuclease, deoxyribonuclease, and Pronase. Purified LPS responded positively in a colorimetric assay for lipopolysaccharide. Electron microscope examination of the LPS both before and after purification demonstrated a heterogeneous mixture of forms including spheres, doughnuts, and ribbons. The trilaminar nature of the ribbon forms was observed by both negative staining and thin sectioning. Lyophilization of the LPS caused an increase in the number and length of ribbon forms seen. Results suggest that the surface layers of treponemes are similar to those of gram-negative bacteria.

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)