Antigen-specific cytotoxic T lymphocytes target airway CD103+ and CD11b+ dendritic cells to suppress allergic inflammation

Allergic airway inflammation is driven by the recognition of inhaled allergen by T helper type 2 (Th2) cells in the airway and lung. Allergen-specific cytotoxic T lymphocytes (CTLs) can strongly reduce airway inflammation, however, the mechanism of their inhibitory activity is not fully defined. We used mouse models to show that allergen-specific CTLs reduced early cytokine production by Th2 cells in lung, and their subsequent accumulation and production of interleukin (IL)-4 and IL-13. In addition, treatment with specific CTLs also increased the proportion of caspase(+) dendritic cells (DCs) in mediastinal lymph node (MLN), and decreased the numbers of CD103(+) and CD11b(+) DCs in the lung. This decrease required expression of the cytotoxic mediator perforin in CTLs and of the appropriate MHC-antigen ligand on DCs, suggesting that direct CTL-DC contact was necessary. Lastly, lung imaging experiments revealed that in airway-challenged mice XCR1-GFP(+) DCs, corresponding to the CD103(+) DC subset, and XCR1-GFP(-) CD11c(+) cells, which include CD11b(+) DCs and alveolar macrophages, both clustered in the areas surrounding the small airways and were closely associated with allergen-specific CTLs. Thus, allergen-specific CTLs reduce allergic airway inflammation by depleting CD103(+) and CD11b(+) DC populations in the lung, and may constitute a mechanism through which allergic immune responses are regulated.

The way forward for transcultural nursing

This paper suggests that the incorporation of a sociological perspective into transcultural nursing would enhance the present anthropological approach. The discussion considers the concept of ethnicity, which encompasses a wider perspective than that of culture alone, and is inclusive of both dominant and subordinate human social groupings. Anthropological understanding explores the beliefs and values of a particular community whereas sociological understanding reflects the position of that community within society and their associated experiences. The case is made by discussion of transcultural nursing, its roots in anthropology and the contribution that a sociological perspective can provide. Concepts of assimilation and acculturation are discussed, as is the adaptive nature of culture. A need for application of theoretical understanding to professional practice is demonstrated and a requirement for development of cultural competence is highlighted. The implications for curriculum development are discussed. This paper adopts a perspective that considers transcultural health care from the focal point of the user of health care service rather than the more usual dominant provider viewpoint.

Activation of NMDA receptors in the suprachiasmatic nucleus produces light-like phase shifts of the circadian clock in vivo

Although there is substantial evidence that glutamate mimics the effects of light on the mammalian circadian clock in vitro, it has been reported that microinjection of glutamate into the suprachiasmatic nucleus of the hypothalamus (SCN) region in vivo does not result in a pattern of phase shifts that mimic those caused by light pulses. The present study was designed to test the hypothesis that microinjection of NMDA into the SCN would induce light-like phase shifts of the circadian clock through activation of the NMDA receptor. Hamsters housed in constant darkness received microinjections of NMDA through guide cannulas aimed at the SCN region at various times throughout the circadian cycle. Wheel running was monitored as a measure of circadian phase. Microinjection of NMDA resulted in circadian phase shifts, the size and direction of which were dependent on the time of injection. The resulting phase-response curve closely resembled that of light. The circadian response showed a clear dose-dependence at circadian time (CT) 13.5 but not at CT19. Both phase delays and advances induced by NMDA were blocked by coinjection of the NMDA antagonist 2-amino-5-phosphopentanoic acid but were slightly attenuated by the non-NMDA antagonist 6-nitro-7-sulfamoylbenzo[f]quinoxaline-2,3-dione disodium. The ability of NMDA to induce phase shifts was not altered by coinjection with tetrodotoxin. These data are consistent with the hypothesis that activation of NMDA receptors is a critical step in the transmission of photic information to the SCN.

First trimester maternal serum concentrations of fetal antigen 2 in normal pregnancies and those affected by trisomy 21

Serum concentrations of fetal antigen 2 (FA-2), the amino-propeptide of the alpha1 chain of collagen type I, were measured in peripheral blood from women with normal (n = 234) and trisomy 21 affected (n = 14) pregnancies between 9 and 11 weeks gestation. Serum FA-2 concentrations were seen to be stable throughout this period, and though raised FA-2 concentrations were seen at the 10th week of gestation, a statistically significant difference between normal and trisomy 21 affected pregnancies was not found overall. Therefore it seems unlikely that FA-2 has a role in first trimester screening for trisomy 21, despite the fact that significantly higher FA-2 concentrations in trisomy 21 and significantly lower concentrations in trisomy 18 had been previously demonstrated in amniotic fluid in the second trimester.

Abnormal amniotic fetal antigen 2 concentrations in trisomy 18 and trisomy 21

Fetal antigen 2 (FA-2) is a human protein, first identified in amniotic fluid, and shown to be identical to the aminopropeptide of the alpha 1 chain of collagen type I. It exists in several different size and charge forms. In the present study, FA-2 was measured in amniotic fluid using two different assays: a rocket line immunoelectrophoretic assay which measured total FA-2, and a radioimmunoassay which was specific for the high molecular mass forms of FA-2. Both assays gave similar results. FA-2 concentrations were measured in amniotic fluid samples collected from normal pregnancies at 10-23 weeks gestation; they were shown to rise steeply from 10-14 weeks, peak at 17 weeks and then fall slightly by 23 weeks. Comparison between amniotic fluid from normal pregnancies and pregnancies affected by trisomy, showed significantly higher FA-2 concentrations in trisomy 21 and significantly lower concentrations in trisomy 18.

The typing of fetal antigen 2 in human amniotic fluid

Fetal antigen 2 (FA-2) has been identified in amniotic fluid and shown to be of fetal origin. In this study we have extended previous observations on FA-2 heterogeneity with respect to both size and charge using gel filtration, ion-exchange chromatography, non-dissociating polyacrylamide gel electrophoresis and sodium dodecyl sulphate polyacrylamide gel electrophoresis. From the diversity of forms we have been able to define two principal FA-2 types, type A and type B. Type A has a high molecular mass (140 kDa), has subunits of 33 kDa and 29 kDa, and elutes at approximately 0.27 mol/l sodium chloride from diethylaminoethyl (DEAE)-Sephacel. Type B has the same mass and subunits as type A, but elutes at approximately 0.24 mol/l sodium chloride from DEAE-Sephacel. Other low molecular mass forms of FA-2 have also been identified. All FA-2 forms described were shown to be common to all amniotic fluid samples studied and were not attributable to artefacts of collection or storage. It was also demonstrated that the recently described FA-2 RIA is specific for FA-2 types A and B and the conversion of arbitrary units FA-2 into micrograms applies to type A. The typing is discussed with respect to (i) the aminopropeptide of the alpha 1 chain of human procollagen type I, (ii) the 24 kDa phosphoprotein in developing bone and (iii) fetal calf ligament protein 1 (FCL-1), suggesting that they are the same protein.

Regulation of T-cell receptor gene expression in human T-cell development

A cDNA clone encoding the alpha chain of the human T-cell antigen receptor was isolated by screening a library from the human T-cell line Jurkat with a mouse alpha-chain cDNA clone. This human alpha-chain clone, together with a human antigen receptor beta-chain cDNA clone, was used to determine the stage of T-cell development at which antigen receptor mRNAs first appear. Blot-hybridization analysis of mRNA isolated from a panel of human thymic tumor lines clearly demonstrated that beta-chain transcripts could be detected in all T-lineage cells. However, alpha-chain transcripts were only found in the most phenotypically mature lines, which express the antigen receptor-associated molecule T3. Furthermore, beta-chain transcripts were abundant in RNA prepared from purified T3-negative thymocytes, whereas alpha-chain transcripts were virtually absent. From these results we conclude that alpha-chain expression occurs later in thymic ontogeny than that of the beta chain and propose that it controls surface expression of the antigen receptor-T3 complex.

The human thymus microenvironment: heterogeneity detected by monoclonal anti-epithelial cell antibodies

Monoclonal antibodies were raised against human thymus stromal cells and their specificity for the epithelial component of thymus stroma assessed by double immunofluorescence using anti-keratin antibodies to identify epithelium. Our monoclonal antibodies identify six distinct patterns of epithelial cell antigen expression within the thymus: pan epithelial (antibody IP1); cortex (MR3 and MR6); cortical/medullary junction (IP2); subcapsule and subpopulation of medulla (MR10/MR14); Hassall's corpuscles and adjacent subpopulation of medulla (IP3); Hassall's corpuscles only (MR13/IP4). This heterogeneity of antigen expression suggests that many different epithelial microenvironments exist within the human thymus.

A study of short-term absence from work among a group of third year student nurses

The objective of the study was to investigate short-term absence (STA) taken by a group of student nurses during the 3-year training period. The amount of, reasons given for, and attitudes towards such absence were considered. The information was attained by means of a questionnaire, interviews with selected students and analysis of data from hospital records. A group of 30 student nurses, approaching the end of their training, co-operated in the study. The methods used in the study are described and the findings which emerged are described and discussed.

Infection of inbred and nude (athymic) rats with Brugia spp

Infective larvae of Brugia pahangi were injected subcutaneously into inbred PVG (-RTIc) rats, and 'nude' (PVG-rnu/rnu) (athymic) rats. Adult worms or circulating microfilariae were recovered from 20/34 (59%) of PVG-RTIc rats and from 30/30 (100%) of 'nude' rats. Fertile worms were regularly found in the lumbar lymphatics and hearts of both strains of rat. Blood eosinophilia first developed in PVG-RTIc rats about 17 days, and in all such animals by 6 weeks. High circulating eosinophil counts persisted only in patent animals, proving a useful hallmark for the presence of microfilariae. Nude rats despite patency, developed eosinophilia only latterly and then to a lesser extent. Specific anti-B. pahangi IgG antibody was first detected at 7 days in all infected PVG-RTIc rats, with levels rising until 8 weeks and remaining high only in microfilaraemic animals; total IgE showed a similar response. Specific IgE rose in all the eight patent rats inconsistently and only to low levels in eight non-patent infected rats. IgG and IgE were undetectable in nude rats. Other strains of inbred rats of different RTI haplotype were also successfully infected with B. pahangi and the human parasite B. malayi, a total of 10/23 (43%) and 5/15 (33%) becoming patent respectively. In the small numbers tested no major influence of RTI haplotype was detected. Infection by the intraperitoneal route did not result in the development of microfilariae. The difference in patency rates between 'nude' and normal PVG rats supports the contention that the development of filarial infections is T lymphocyte dependent. Inbred and 'nude' rats provide a valuable model of human filariasis, in which many features of filarial immunopathology can be studied.

Human atrial and ventricular myosin light-chains subunits in the adult and during development

1. Myosin was isolated from human right- and left-atrial and -ventricular myocardium, and examined both in adult subjects and at different stages during pre- and post-natal development. 2. The myosin light-chain subunits in the atria and ventricles were different when characterized by isoelectric focusing and subsequent two-dimensional poly-acrylamide-gel electrophoresis. 3. No differences were observed between the light-chain subunits in the right and left ventricle at any stage of development. 4. The foetal ventricle contained a characteristic light chain that was a major component throughout the latter half of gestation. This foetal light chain, which disappeared in the postnatal period, could not be distinguished from adult atrial light chain 1 on two-dimensional electrophoresis. 5. Myosin in the adult atria, particularly the left, contained components similar to ventricular light-chain components. 6. The possible stimuli for the observed changes in myosin light-chain expression are discussed in relation to the known physiological changes occurring during development.

Myosin adenosinetriphosphatase activity and light chain subunit composition of human right and left ventricle

Myosin was isolated from the free right and left ventricular wall of normal adult human myocardium and purified until actin contamination was considered negligible as judged by sodium dodecyl sulphate polyacrylamide gel electrophoresis and adenosine triphosphatase assay in the presence of magnesium chloride. Ca2+ and K+ ethylenediaminetetra-acetic acid activated adenosine triphosphatase activities were determined in the presence of 3 mmol.litre-1 adenosine triphosphate. Myosin light chain subunits, VLC-1 and VLC-2, were analysed by polyacrylamide gel electrophoresis using: (i) sodium dodecyl sulphate at pH 7.0; (ii) 6 mol.litre-1 urea at pH 8.5; and (iii) isoelectric focusing in 9.2 mol.litre-1 urea over the pH range 4 to 6. No inherent differences in enzymic or physiochemical properties of the myosins from the human right and left ventricle were observed. Similar results were obtained in the baboon and dog.

Foetal myosin light chain in human ventricle

Myosin light chain subunits from adult human atria and ventricle were characterized by two-dimensional gel electrophoresis. Atrial (ALC-1 and ALC-2) differed from ventricular (VLC-1 and VLC-2) light chains. Foetal (18--21 week) ventricle contained VLC-1 plus a foetal light chain (FLC-1) which could not be distinguished from adult ALC-1. Myosin FLC-1 was gradually lost from the ventricle and replaced by VLC-1 during foetal development and in the immediate postnatal period.