Indoor air pollutants: limited-resource households and child care facilities.

This paper reports on a study of indoor air quality in homes and child care facilities in non-metropolitan counties of New York State. Specific pollutants examined were lead, radon, carbon monoxide, asbestos, and mold. Some homes had high levels of pollutants, and certain pollutants were significantly and negatively correlated with household income. High levels of pollutants also were observed in many child care facilities, which raises questions about constant exposure of children to pollutants. Recommendations are made for lowering pollutant levels in low-income households and child care facilities.

Distinctive microvillous brush border staining with HBME-1 distinguishes pleural mesotheliomas from pulmonary adenocarcinomas.

HBME-1 is an antimesothelial monoclonal antibody that recognises an unknown antigen on microvilli of mesothelioma cells. The aim of this study was to evaluate the staining pattern with respect to antibody dilution, cellular distribution and intensity of immunohistochemical staining with HBME-1 in pleural mesotheliomas compared with pulmonary adenocarcinomas. A total of 27 pulmonary adenocarcinomas and 26 mesotheliomas were stained with commercially available HBME-1 at various antibody dilutions and evaluated for the site (membranous, +/- microvillous brush border or cytoplasmic), intensity and percentage of cells staining. On light microscopy, 23 mesotheliomas showed distinctive microvillous brush border staining with HBME-1 (three mesotheliomas--two sarcomatoid and one poorly differentiated--were negative). Twenty-five adenocarcinomas showed membranous +/- cytoplasmic staining but lacked the distinctive microvillous brush border staining. In a subgroup of tumours studied by electron microscopy following immunogold labelling by HBME-1, all of 16 mesothelioma cases showed strong immunogold labelling in the membranes of the long microvilli. In contrast, the 12 cases of pulmonary adenocarcinomas showed minimal labelling in the membranes of the short microvilli, but staining was seen within vesicles, often near the surface of the cells. This study shows that the presence of a distinctive microvillous brush border by immunohistochemical staining with HBME-1 allows distinction between pleural mesotheliomas and pulmonary adenocarcinomas (sensitivity of 88%, specificity of 100%). The difference in the ultrastructural distribution of immunogold labelling with HBME-1 between mesotheliomas and adenocarcinomas underscores the light microscopy findings.

Electron microscopic assessment of smeared or imprinted specimens of solid tumours.

The aim of this study was to develop a reliable method for preparation of smeared or imprinted cytology specimens for electron microscopic examination. Ten different solid tumours were studied. In each case one air-dried (Diff-Quik stained) and one alcohol-fixed (Pap stained) smear was prepared for diagnostic purposes. Simultaneously, a third smear or imprint was prepared for electron microscopy on a coverslip that was coated with poly-L-lysine and attached to a glass slide using double-sided adhesive tape. The smear or imprint was primary fixed in 2% glutaraldehyde in 0.1 M phosphate buffer, pH 7.4, for 2 hours. The coverslip was removed from the slide, placed in a glass petri dish and processed for electron microscopy. The smear/imprint on the coverslip was embedded in resin on a silicon embedding mould and allowed to polymerise for 8-12 hours. The coverslip was removed using liquid nitrogen and the block sectioned using standard techniques as for a monolayer. The specimens collected for electron microscopy using this technique yielded sufficient material for assessment with excellent tissue preservation producing good ultrastructural detail. Focal mechanical damage was seen in some specimens but diagnostic areas were always found within the block. As the smear/imprint can be regarded as a monolayer, the processing time can be reduced compared with solid tissue specimens. This technique ensures that well-preserved tissue is available for electron microscopy even when the sample size is very limited.

Parental language and verbal responsiveness to children in crowded homes.

This article is a secondary data analysis of the University of Kansas Language Acquisition Project, which intensively studied, on a regular basis, parent and child language from age 6 months to 30 months. The association between residential density and parent-child speech was examined. Parents in crowded homes speak in less complex, sophisticated ways with their children compared with parents in uncrowded homes, and this association is mediated by parental responsiveness. Parents in more crowded homes are less verbally responsive to their children. This in turn accounts for their simpler, less sophisticated speech to their children. This mediational pathway is evident with statistical controls for socioeconomic status. This model may help explain prior findings showing a link between residential crowding and delayed cognitive development.

Acute pain management: evaluation of the effectiveness of intravenous patient-controlled analgesia with vascular patients.

A new technique of postoperative analgesia now widely used throughout North America is patient-controlled analgesia (PCA). With this technique, patients manage acute pain by self-administering postoperative IV narcotics. Vascular patients, who often suffer from multiple disease processes of the cardiovascular system, are excellent candidates for IVPCA since effective pain management has the potential to reduce the incidence of complications. However, no studies to date have examined the use of patient-controlled analgesia with vascular patients. This retrospective, descriptive study identifies the demographic characteristics, dosing patterns, and side-effects evident in vascular patients placed on IV morphine PCA following surgery. The results of this study suggest that the use of IVPCA with an older patient group, such as vascular patients, can be successful when implemented as part of a program established and monitored by an Acute Pain Service.

Innovation adoption: introducing I.V. patient controlled analgesia to the nursing workplace.

Technology in the nursing workplace is inevitable but what is not certain is how well these technologies will be initially accepted by nurses. One technological innovation that has appeared in some Canadian hospitals is IV Patient Controlled Analgesia (IV PCA), an innovative technique for pain management, employing the use of a computer-driven pump. Few nursing studies have examined the adoption of technological innovations. This qualitative study examines the incorporation of IV PCA to the nursing workplace and job-related factors that influenced it. A five-phase integration process was identified along with factors impacting on this process. Incorporating IV PCA into nursing practice involved the nurses' judgements of the influence of this innovation on the nurses' comfort with care delivery; the patient/nurse relationship; managing the technology; and the relationship with other health care professionals and patients' family/visitors. Anxiety accompanied the integration process, peaking as IV PCA was introduced to patient care. Findings of this study suggest that actions and decisions initiated by nurse administrators and educators have the potential to influence the successful adoption of this innovation.

Immunogold-silver staining method for light and electron microscopic detection of lymphocyte cell surface antigens with monoclonal antibodies.

We used the immunogold-silver staining method (IGSS) for detection of lymphocyte cell surface antigens with monoclonal antibodies in light and electron microscopy and compared this procedure with the immunogold staining method. Two different sizes of colloidal gold particles (5 nm and 15 nm) were used in this study. Immunolabeling on cell surfaces was visualized as fine granules only by IGSS in light microscopy. The labeling density (silver-gold complexes/cell) and diameters of silver-enhanced gold particles on cell surfaces were examined by electron microscopy. Labeling density was influenced not by the enhancement time of the physical developer but by the size of the gold particles. However, the development of shells of silver-enhanced gold particles correlated with the enhancement time of the physical developer rather than the size of the colloidal gold particles. Five-nm gold particles enhanced with the physical developer for 3 min were considered optimal for this IGSS method because of reduced background staining and high specific staining in the cell suspensions in sheep lymph. Moreover, this method may make it possible to show the ultrastructure of identical positive cells detected in 1-micron sections counterstained with toluidine blue by electron microscopy, in addition to the percentage of positive cells by light microscopy.

Induction of class I major histocompatibility complex antigen expression by West Nile virus on gamma interferon-refractory early murine trophoblast cells.

Primary murine trophoblast giant cells (TGC) do not express detectable major histocompatibility complex (MHC) antigens and are refractory to the MHC-increasing effects of alpha and beta (virus-induced) interferons and gamma (immune type) interferon during early implantation (postcoital days 3.5-6). West Nile virus infection of primary TGC monolayers from postcoital-day-3.5 preimplantation blastocysts induced paternal MHC antigen expression within 16 hr, as detected by immunogold labeling for electron microscopy. Induction is unlikely to have been mediated by secreted virus-induced interferons or other factors, as it occurred in the presence of high concentrations of anti-alpha/beta interferon antibodies and was not induced by virus-inactivated supernatants from MHC-induced primary TGC cultures. Attempts to induce MHC antigen expression with poly(I.C) or recombinant tumor necrosis factor alpha in primary TGC cultures also failed. Thus, the apparent inhibition of MHC antigen expression in primary TGC during early implantation and their refractoriness to induction of de novo MHC antigen expression is not absolute. This may represent a maternal-and/or species-protective evolutionary device. As such, manipulation of this phenomenon may allow a conclusive assessment of the significance of inhibition of MHC antigen expression on trophoblast cells in the implanting semiallogeneic embryo.

Isolation of colonic crypts that maintain structural and metabolic viability in vitro.

The aim of this study was to develop a method by which colonic epithelial cells can be isolated from resected mucosa or colonoscopic biopsy specimens and viability maintained in the short term. The principles of the technique are to digest the lamina propria from the epithelium with Dispase and collagenase, to disrupt the epithelium by trituration, and to purify the epithelial cells by seiving and differential sedimentation. Whole and partial crypts were isolated with consistently high purity of 93.5% +/- 1.2% (excluding red cells). Structural integrity was confirmed by light and electron microscopy, exclusion of trypan blue, minimal leakage of lactic dehydrogenase over 5 h (4.1% +/- 1.7%), and 51Cr leakage of less than 2% per hour over 16 h. Functional integrity was supported by continued deoxyribonucleic acid synthesis [( 3H]thymidine uptake) over 16 h and the formation of epithelial monolayer cultures on plastic. Thus, this simple method yields a highly enriched cell population that maintains high viability in vitro for at least 16 h. Such cells may be useful for the study of the biology of colonic epithelial cells.

Class I major histocompatibility complex antigen expression on early murine trophoblast and its induction by lymphokines in vitro. II. The role of gamma interferon in the responses of primary and secondary giant cells.

The induction of paternal Class I and II MHC antigens by crude lymphokine preparations or purified recombinant gamma interferon was investigated on (C57BL/6J X CBA/H)F1 primary and secondary trophoblast giant cell outgrowths from 3.5-day post-coital (pc) blastocyst and 7.5-day pc ectoplacental cone preparations, respectively, using sensitive immunogold labelling techniques and electron microscopy. Class I MHC (but not Class II) antigens could readily be induced on secondary trophoblast giant cells, by incubation in vitro with gamma interferon for 40 h. However, repeated attempts to induce detectable MHC antigens on primary trophoblast giant cells failed. Mock-treated (C57BL/6J X CBA/H)F1 secondary trophoblast giant cell control preparations failed to express detectable MHC antigens. These findings suggest that, at the time of implantation, there is a time window during which MHC antigens are neither expressed constitutively nor are inducible by soluble factors which normally modulate cell surface MHC antigen concentration.

Class I major histocompatibility complex antigen expression on early murine trophoblast and its induction by lymphokines in vitro.

The expression of paternal class I and class II major histocompatibility complex (MHC) antigens in cultures of murine ectoplacental cone trophoblast was examined using immunogold labelled antibodies and electron microscopy. Class I MHC antigens could be induced on ectoplacental cone derived trophoblast following exposure to concanavalin A stimulated T cell supernatants. Class I MHC antigens were not detected in untreated trophoblast cultures. Class II MHC antigens were never detected on trophoblast whether treated or untreated. This is the first report of the experimental induction of Class I MHC antigens on a population of normally MHC-negative trophoblast cells.

Activity of divicine in Plasmodium vinckei-infected mice has implications for treatment of favism and epidemiology of G-6-PD deficiency.

Intravenous injection of divicine into mice infected with Plasmodium vinckei rapidly killed the parasites and caused haemolysis. Degenerating parasites were observed frequently inside intact circulating erythrocytes, implying that parasite death was not a passive consequence of haemolysis. Both parasite death and haemolysis were prevented by the iron chelator desferrioxamine. In vitro, divicine caused the accumulation of malonyldialdehyde and the depletion of reduced glutathione in normal mouse erythrocytes. Desferrioxamine inhibited the former event, but not the latter. These observations support the hypothesis advanced by Huheey & Martin (Experientia, 31, 1145, 1975) to explain the patchy geographical distribution of glucose-6-phosphate dehydrogenase deficiency in historic malarial areas and also suggest that desferrioxamine, a drug already in clinical use, is a potential treatment for favism and other examples of oxidative haemolysis.

Radical-mediated damage to parasites and erythrocytes in Plasmodium vinckei infected mice after injection of t-butyl hydroperoxide.

Intravenous injection of t-butyl hydroperoxide rapidly killed Plasmodium vinckei in mice, and caused haemolysis. The same dose seemed harmless to unparasitized mice. Many parasites disintegrated inside circulating erythrocytes, so parasite death was not simply a passive consequence of haemolysis. Injection of desferrioxamine, which removes the traces of free iron that promote the dissociation of t-butyl hydroperoxide into radical species, prevented both parasite death and haemolysis. Lipid peroxidation, as measured by accumulation of malonyldialdehyde over 2 h in vitro, occurred in erythrocytes exposed to t-butyl hydroperoxide, and was particularly marked in erythrocytes from parasitized mice. These erythrocytes accumulated appreciable malonyldialdehyde even without exposure to t-butyl hydroperoxide. Desferrioxamine inhibited the accumulation of malonyldialdehyde, but did not prevent depletion of reduced glutathione by t-butyl hydroperoxide. This suggests that t-butyl hydroperoxide damaged parasites and erythrocytes by dissociating into radical species, rather than by decreasing intraerythrocyte anti-oxidant capacity. In earlier experiments we suggested that intraerythrocytic parasite death and haemolysis caused by alloxan were mediated by radical species, and these experiments with t-butyl hydroperoxide add weight to this interpretation. We regard both of these systems as models for macrophage-induced parasite death and host pathology in acute malaria.

Malignant haemangiopericytoma: case report and ultrastructural study.

A case of a rapidly fatal malignant haemangiopericytoma arising in the deep tissues of the face is recorded. The histology of the tumour was anaplastic but otherwise typical. Ultrastructural study confirmed the diagnosis by revealing tumour cells with delicate interdigitating cytoplasmic processes and basement membrane formation resembling pericytes. A feature of the tumour not previously recorded in haemangiopericytoma was ciliogenesis.