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Chronic inflammatory bowel diseases, ulcerative colitis and Crohn's disease, are thought to be distinct clinical entities. The mechanisms involved in the pathogenesis of the diseases are poorly understood, however, it is thought that dysregulation of the immune system, especially of the mucosal immune reactivity, as well as a genetic susceptibility and environmental factors, e.g. bacterial flora, may each contribute to initiation and/or progression and chronicity of the diseases. Experimental animal models are available to study the different components involved in inflammatory bowel disease and to complement our understanding of chronic inflammatory reactions in these organs ultimately leading to effective alternative therapeutic approaches.

Many cell types efficiently present an epitope of the hepatitis B surface Ag (HBsAg) to murine class I-restricted CTL following an in vitro pulse with native 22-nm HBsAg particles. Processing of exogenous HBsAg particles required its cytochalasin B-insensitive uptake and acid proteolysis in an endocytic compartment, was insensitive to brefeldin A and cycloheximide, and did not involve regurgitation of antigenic peptides. In contrast, after an in vitro pulse of cells with exogenous, heat-denatured 1-micron HBsAg aggregates, only macrophages (but not other cell types tested) presented the Ld-restricted HBsAg epitope efficiently to CTL. Processing of exogenous HBsAg aggregates required its cytochalasin B-sensitive uptake, was insensitive to brefeldin A, and involved regurgitation of antigenic peptides. Processing of the two different, exogenous HBsAg preparations for class I-restricted epitope presentation thus involved alternative pathways: an "endocytic pathway" for native 22-nm particles, and a "phagocytic pathway" for denatured 1-microns aggregates. Both HBsAg preparations displayed different immunogenicity for class I-restricted CTL in vivo when delivered without adjuvants: native HBsAg particles were of high immunogenicity, and denatured HBsAg aggregates were of low immunogenicity. Class I-restricted CTL are thus primed in vivo after "endocytic processing" of native HBsAg particles as well as "phagocytic processing" of denatured HBsAg aggregates.

Injection of low doses of particulate hepatitis B surface Ag (HBsAg) into H-2d mice without adjuvants primes an Ld-restricted, S28-39-specific T cell response. This study indicates that dendritic cells (DC) and macrophages (M phi) both serve as APCs that support priming of CD8+ CTL precursors in vivo to exogenous HBsAg particles. After transfer into a syngeneic, naive host, HBsAg particle-pulsed DC, either freshly purified from skin or derived from a cloned DC line, efficiently primed class I-restricted, HBsAg-specific CTL precursors. M phi, either harvested from the peritoneal cavity or generated in macrophage-CSF-stimulated bone marrow cell cultures in vitro or derived from established, cloned M phi lines (PU5-1.8, J774A.1), pulsed with HBsAg particles in vivo or in vitro, elicited a class I-restricted, HBsAg-specific CTL response after adoptive transfer into naive hosts. The class I-restricted CTL response induced by HBsAg particle immunization was suppressed in carrageenan-treated mice, but was restored when carrageenan-treated mice were immunized with syngeneic, HBsAg-pulsed M phi. Selective elimination of M phi by liposome-incorporated dichloromethylene-diphosphonat did not suppress the induction of a CTL response of H-2d mice by HBsAg particle immunization. HBsAg-pulsed, freshly prepared DC are more potent than pulsed M phi in priming class I-restricted CTL in vivo. The relative importance of both types of APC in priming CTL remains to be resolved.

We investigated lamina propria T cells from the small intestine (jejunum/ileum) and the large intestine (colon) of euthymic (BALB/c, C.B-17, C57BL/6) and athymic (C57BL/6 nu/nu; BNX bg/bg nu/nu xid/xid) mice. CD3+ T cells represented about 40% of the lamina propria lymphocytes (LPL) from the small or the large intestine of euthymic mice, and 20-30% of the LPL populations from the small or large intestine of athymic mice. In the lamina propria T cell population of the small intestine, 85% were of the alpha beta lineage in euthymic mice, but only 40% were of the alpha beta lineage in athymic mice. T cells of the gamma delta lineage were thus more frequent than T cells of the alpha beta lineage in the intestinal lamina propria T cells of extrathymic origin. CD4+ T cells represented 40% of the lamina propria T cells in the small as well as in the large intestine of euthymic mice, and 20-30% of the T cells in the lamina propria of the nude mouse gut. In euthymic mice, 40% of the T cells in the small intestine lamina propria, and 30% of the T cells in the colonic lamina propria were CD8+. In intestinal lamina propria T cell populations of athymic mice, the CD8+ T cell population was expanded. Most (60-70%) CD8+ T cells in the lamina propria of the small and the large intestine of euthymic and athymic mice expressed the homodimeric CD8 alpha + beta- form of the CD8 coreceptor. A fraction of 15-20% of all CD3+ T cells in the lamina propria of the small and the large intestine of euthymic and athymic mice were 'double negative' CD4- CD8-. A large fraction of the TCR alpha beta + T cells in the colonic lamina propria (but not in the small intestine lamina propria) of euthymic mice expressed the CD2 and the CD28 costimulator molecules, the adhesion molecule LECAM-1 (CD62 L), and could be activated in vitro by CD3 ligation. These data reveal a considerable heterogeneity in the surface phenotype and the functional phenotype of murine lamina propria T cells.

Cogan's syndrome is an uncommon disease characterized by ocular inflammation, vestibuloauditory dysfunction and symptoms of systemic disease. The etiology is unknown, however there is evidence for an autoimmune pathogenesis. The "typical" Cogan's syndrome presents as bilateral interstitial keratitis and progressing vestibuloauditory dysfunction. The presence of other inflammatory manifestations in addition of keratitis has been termed as "atypical" Cogan's syndrome.We report on six patients presenting with typical as well as atypical ocular manifestations between 1982 and 1994. Typically, the illness was accompanied by systemic symptoms. Each patient had audiovestibular involvement, that was the initial presentation in 4 cases. Vestibular dysfunction often preceded hearing loss. Five of our patients not only presented with keratitis but also demonstrated signs of ocular inflammation diagnosed as scleritis or episcleritis. In two patients these ocular symptoms were the first signs of Cogan's syndrome, recurred periodically and did not respond to corticosteroids.In 3 patients that were diagnosed early and treatment with corticosteroids was initiated early, hearing could be stabilized, in the remaining patients total bilateral deafness could not be prevented.The importance of being aware that vestibuloauditory dysfunction may occur in patients with ocular inflammation, and the fact that early immunotherapy may prevent the risk of deafness, has to be emphasized.

The MACHO Collaboration's search for baryonic dark matter via its gravitational microlensing signature has generated a massive database of time ordered photometry of millions of stars in the LMC and the bulge of the Milky Way. The search's experimental design and capabilities are reviewed and the dark matter results are briefly noted. Preliminary analysis of the approximately 39,000 variable stars discovered in the LMC database is presented and examples of periodic variables are shown. A class of aperiodically variable Be stars is described which is the closest background to microlensing which has been found. Plans for future work on variable stars using the MACHO data are described., 10 pages with 5 bitmapped figures, uuencoded compressed PostScript. Text and full resolution figures at ftp://igpp.llnl.gov/pub/kcook/macho-var Invited review for Proceedings of IAU Colloquium 155: Astrophysical Applications of Stellar Pulsation (Cape Town, February 1995), ASP Conference Series, eds. R. Stobie and P. Whitelock

Gravimetric changes in marble and limestone briquettes exposed to outdoor environment at five sites in the eastern United States have been monitored since 1984. An earlier report describes procedures and results obtained in 1984--1988. This report presents the results of the exposure period 1984--1988 and reviews and summarizes those of prior years. A linear relationship was found between cumulative gravimetric losses and exposure period or rain depth. These losses resulted in an average recession rate of 14 to 24 {mu}m/yr for marble and twice that for limestone. Variations in recession among the various exposure sites can be ascribed to differences in rain depth and hydrogen ion concentration. The annual recession rates obtained from gravimetry yielded rates that were for marble twice those obtained from runoff experiments, and more than three times those for limestone; this indicates that physical erosion plays an important role. Gravimetric monitoring of exposed briquettes is continuing in a planned 10-yr program.

Oxygen and hydrogen removal by cold trapping is a standard technique for liquid metals such as Na and NaK, compare e.g. [1]. In order to achieve high efficiencies these cold traps are often filled with wire meshs. In the past these cold traps often plugged much earlier than expected. This was due to an improper design because of an insufficient knowledge of the precipitation kinetics. Although considerable progress has been achieved in the last years in the understanding of the impurity removal from sodium, there were still open questions concerning the impurity removal at very low concentration ranges.

Bei 41 Patienten in einem mittleren Alter von 57,9 ± 12,5 Jahren wurden 32 Silikonlinsen (Iovision 201) und 28 PMMA-Linsen (AMO-Array) implantiert. Beide Linsen-typen realisieren sehr ahnliche Sehqualitaten beziiglich Nah- und Fernvisus, Kontrastseh-scharfe und Blendungsempfindlichkeit. Von den 60 Augen mit implantierter MIOL haben nach zwei Jahren 6 Augen (10%) eine Kapselfibrose entwickelt, die mit dem Nd-YAG-Laser behan-delt wurde. Eine Defokussierkurve wurde vor und nach Kapsulotomie aufgenommen. Kapselfibrose reduziert den Fernvisus, und die Nahsehscharfe bei MIOL geht verloren. Nach Kapsulotomie wird die optisch wirksame Flache einer HKL vom Pupillendurchmesser sowie der vorderen und hinteren Kapseloffnung bestimmt. Das Zentrum der Multifokallinse mit einer Flache von 2,2 mm Durchmesser ermoglicht praktisch nur ein monofokales Sehen. Deshalb mussen Pupille und Kapseloffnungen einen Mindestdurchmesser aufweisen, um den Mehr-starkeneffekt einer MIOL zur Wirkung kommen zu lassen.

We developed a model in which full-thickness human genital mucous membranes (fallopian tubes, endometrium) were heterotopically xenografted into the skin of severe combined immunodeficient (SCID) mice. The transplanted tissue retained its human phenotype for at least 4 weeks including the glandular epithelium, the lamina propria, and main parts of the grafted vessels. By using an occlusive chamber filled with covering phosphate-buffered saline we created a system that protected the moist human epithelial surface. This system will allow the study of the interaction of test substances, or of invasive, pathogenic microorganisms, with epithelial cells and other cellular components of the human genital mucosa under in vivo conditions.

New insights into HIV-pathogenesis suggest that the cell mediated immune response might play a crucial role in controlling HIV infection by suppressing HIV-replication in CD4-positive cells by a lymphokine-like soluble factor and by killing HIV-infected cells via classical CTL mediated lysis. This type of a cellular immune response rather than an antibody response seems to be most promising to protect if not from infection, so at least from disease. Therefore rationally designed candidate vaccines should be capable of inducing a cell mediated immunity in addition to a humoral immune response. In order to avoid adverse side effects upon immunization, carefully selected antigens and epitopes should be presented in a favourable manner to the immune system. In previous experiments, we could demonstrate that the gag-polyprotein precursor, known to include a series of T-helper and CTL epitopes, assembles to highly immunogenic, complete noninfectious HIV-1 virus-like particles (VLP). Based on these VLP we developed a novel antigen presentation system, which allows the presentation of selected epitopes derived from HIV reading frames other than gag to the immune system. Alternatively complete derivatives of the HIV-1 external glycoprotein can be presented by the VLP. Immunological analysis of different VLP preparations in a BALB/c mouse model revealed the induction of a strong CTL response. The significance of these observations for future vaccine strategies is discussed.

CD8+ cytotoxic T lymphocytes (CTL) mediate protective immunity against many intracellular pathogens. New generation vaccines that exploit the potential of recombinant protein technology have to meet the challenge to identify immunodominant antigen systems of the pathogen of interest, to produce these antigens in recombinant form, and to find ways to selectively deliver them to the compartments of the specific immune system that mediate the protective responses. Immunization with soluble protein antigens usually primers CD4+ T cells but not CD8+ T cells because of the stringent requirements for 'endogenous processing' for major histocompatibility complex (MHC) class I-restricted epitope presentation to CD8+ CTL. This rule is not absolute because priming of class I-restricted CTL by soluble, recombinant viral protein antigens injected without adjuvants has been reported in various antigen systems. An understanding of the cell biology of alternative pathways of protein antigen processing for MHC class I-restricted epitope presentation is emerging. We describe subcellular sites, alternative peptide transport mechanisms, and alternative modes of MHC class I molecule recycling that allow different modes of peptide loading of class I molecules. Experimental evidence for some of these novel pathways of 'endogenous' processing for class I-restricted epitope presentation is discussed. Some pathways are still hypothetical. The issue of alternative modes of 'endogenous' processing for class I-restricted antigen presentation is of theoretical and practical relevance. Immunologists are interested in the question from which source protein antigens are derived that are potentially accessible to specific recognition by different T cell subsets.(ABSTRACT TRUNCATED AT 250 WORDS)

Many hypertensive patients have other, usually long-term diseases. Antihypertensive therapy may interfere with these diseases and their therapies. In the present study, the possible interactions of the ACE-inhibitor perindopril with several of the most common long-term diseases was evaluated.In a multicenter, double-blind, randomized, placebo-controlled trial, the effect of perindopril was evaluated in 490 patients with mild essential hypertension and any one of the following concomitant diseases: hyperlipidemia, type II diabetes mellitus, ischemic heart disease, cardiac arrhythmia, peripheral arterial occlusive disease, nephropathy with proteinuria, chronic obstructive pulmonary disease, or degenerative joint disease treated with nonsteroidal anti-inflammatory drugs (NSAIDs). After a 3-week single-blind placebo run-in, the patients received either perindopril (4 mg/d) or matching placebo for 6 weeks.Blood pressure was effectively reduced by perindopril irrespective of the associated disease. The rate of spontaneously reported side effects was low. Treatment with perindopril was free from adverse interactions with the concomitant diseases and therapies. Moreover, favorable actions could be observed in patients with ischemic heart disease (reduction of maximal ST-segment depression during peak exercise and decrease in the number of angina attacks), in patients with proteinuria (decrease in albuminuria in patients with normal serum creatinine levels), and in patients with NSAID-treatment (increase in prostaglandin E2 concentration in gastric mucosa suggesting gastric cytoprotection).This trial shows that ACE-inhibition with perindopril represents a simple, safe, and effective short-term therapeutic option for the large proportion of patients with mild essential hypertension and concomitant diseases and therapies.

A backcrossed mouse line was established homozygous for the autosomal recessive mutation scid (severe combined immunodeficiency) and carrying T cells which express transgenic (tg) T cell receptor (TCR) alpha and beta chains that mediate H-2 class I (Db)-restricted recognition of a male (H-Y) determinant (TCR-tg SCID mouse). A thymoma arose 'spontaneously' in one of the TCR-tg female SCID mice and the thymoma cells were adopted to factor-independent, in vitro growth in long-term tissue culture. The thymic lymphoma cell line was cloned and one of the subclones, TL1, was studied. The ultrastructure of TL1 cells resembled that of small-to-medium lymphoblasts. The cells had the following phenotype: CD3 + TCR alpha T+TCR beta T+CD4-CD8- CD44-CD45RB+LECAM-1 + IL-2R- and low H-2 expression. Exposure of TL1 cells to TCR-binding monoclonal antibodies or lectins blocked in their in vitro proliferation. In addition, TL1 cell proliferation was inhibited by coculture with male and female H-2b+ cells. Following adoptive transfer into both H-2b+ and H-2d+ SCID recipient mice, TL1 cells showed rapid, malignant growth and infiltrated lymphoid and nonlymphoid organs. Expression of the tg TCR complex was selectively downregulated in TL1 cells growing in H-2b+ male SCID recipients. However, the malignant in vivo growth potential of TL1 cells was comparable, irrespectively of the sex and haplotype of the SCID recipient. In conclusion, our data show that the growth of TL1 cells in vitro is suppressed by physiological ligation of their TCR complex, whereas TL1 cells, by downregulation of their TCR, may escape TCR-ligation-induced suppression in vivo.

Die Implantation von Intraokularlinsen bei Patienten mit hoher Myopie ist ein Diskussionsthema in der Kataraktchirurgie. In der vorliegenden Studie wurden postoperative Ultraschallbiometriedaten unter Anwendung des Linsenberechnungsprogrammes von Methling u. Kalb ausgewertet. Von den 73 nachuntersuchten kataraktoperierten Augen mit Achsenlangen groser als 25 mm lagen bei Kapselsackfixation (42 Augen) die Mittelwerte der Vorderkammertiefe bei 4,81 mm und bei Sulkusfixation (28 Augen) bei 4,50 mm. Im Unterschied zu emmetropen Augen wirkt sich diese Differenz von 0,3 mm nicht auf die Brechkraft in der Hinterkammerlinse aus, falls eine bestimmte postoperative Refraktion angestrebt wird.

This study examined the frequency and nature of pregnancy-related dreams in pregnant women in a family practice center and assessed the extent such dreams were discussed with providers of prenatal care.Pregnant women 18 years of age or older who were receiving prenatal care at the University of Missouri-Columbia Family Medical Care Center responded to a two-page self-administered questionnaire. The major variables measured were frequency of pregnancy-related dreams, frequency of frightening dreams, content of dreams, and discussion of dreams. Health professionals providing prenatal care to these women were also surveyed.Eighty-eight pregnant women, 41 family physicians, and 3 nurse practitioners participated in the study. Dreams about their pregnancy or baby were reported by 59 (67 percent) of 88 pregnant women, of whom 22 had experienced at least one frightening dream. Seventeen women reported being upset by a dream. The frequency of dreams increased with advancing gestational age. The content of the most common dream involved conflict with the father of the baby. Most women had talked to another person about their dreams, usually the baby's father. Only 2 women told their physicians about the pregnancy-related dream. One-half of the providers of prenatal care reported discussing pregnancy-related dreams with a pregnant patient at least once during their careers.Dreams about their pregnancy or baby occurred frequently in pregnant women and could be a neglected source of information about the psychological state of the patient.

In electrically coupled multichannel ducts with a U-bend geometry, magnetohydrodynamic effects can result in strong uneven distributions of flow rates Qi and pressure drops Δpi in the individual channels. A U-bend geometry is part of the KfK self-cooled Pb-17Li blanket design (radial-toroidal-radial channels). However, inserts are proposed which decouple electrically the radial channels (not the toroidal ones). In order to investigate the multichannel effect (MCE), screening experiments with InGaSn were performed with different flow channel geometries and channel numbers between 1 and 5. Hartmann numbers were varied between 0 and 1600 (maximum magnetic flux density: 4.5 T) and Interaction parameters between 0 and 10000. The MCE was modeled using the method of Core Flow Approximation (CFA) valid for infinitely large Interaction parameters. For electrically conducting walls between all channels, the volume flow rates in the outer channels are significantly larger than those in the inner channels for Δpi ≈ const. For Qi ≈ const., the highest pressure drop occurrs in the middle channel and the lowest in the outer channels. There is no significant difference between conducting and nonconducting outside walls. There is also no large difference between the multichannel U-bend and multichannel single bend. The pressure drop coefficient decreases with increasing Interaction parameter N. The extrapolation of these results to very high values of N agrees with the predictions obtained with the CFA. The flow geometry which is similar to the KfK-design, results in a fairly even flow rate and pressure drop distribution. The single channels behaved like electrically separated channels, no marked MCE was observed. This result is also expected by extrapolating theoretical results.

Expression of CD4+ or CD8+ determinants and ten different TCR V beta genes was analysed by two-colour flow cytometry in lymph node cells (LNC) of BALB/c and dm2 (a BALB/c Ld loss mutant) mice. TCR V beta 14 expression of CD8+ T cells and TCR V beta 7 and 14 of CD4+ T Cells were significantly more frequent in BALB/c than in dm2 LNC, whereas no differences were observed in the frequency distribution of TCR V beta+ CD4-CD8- double negative LNC from BALB/c versus dm2 mice. These results represent the first published evidence for positive selection of particular TCR V beta genes by individual MHC class I molecules in non-manipulated mice.

We treated 11 patients with posterior chamber intraocular lenses that were dislocated into the vitreous cavity. Using a pars plana approach, vitrectomy was performed and in order to facilitate manipulation, half of the bulbus volume was filled by perfluorodecaline. The IOL was grasped with forceps and repositioned with a special technique. In this way the first haptic is fixed in the ciliary sulcus. Fixation of the second haptic with 9 x 0 polypropylene suture was performed with a similar procedure. Finally, prophylactic cryotherapy of the retina is indicated.

Die Pravention atherosklerotisch bedingter Herz-Kreislauf-Erkrankungen ist das Hauptziel der Behandlung von Hypercholesterinamien. Viele grose epidemiologische Studien haben den Zusammenhang zwischen der Konzentration des Cholesterins im Blut und der Inzidenz der koronaren Herzerkrankung einerseits und der Ernahrung andererseits belegt [1]. So erbrachte die SiebenLander-Studie [4] eine enge Beziehung zwischen dem Anteil der gesattigten Fette bei der Kalorienaufnahme bzw. dem Nahrungscholesterin und der Mortalitat an koronarer Herzerkrankung. Die Ni-Hon-San-Studie [3] untersuchte Japaner, die nach Anderung ihrer Esgewohnheiten durch Ortswechsel hohere Cholesterinwerte und eine hohere Mortalitatsrate an Herz-Kreislauf-Erkrankungen aufwiesen.

Intravenous injection of 10(6) to 10(7) non-fractionated spleen cells (SC) from C57BL/6 (B6, H-2b) mice into completely allogeneic, immunodeficient H-2d severe combined immuno deficiency (scid) mice leads to engraftment of allogeneic donor T cells. Mice analysed in the tenth week posttransfer had engrafted donor-type CD4+ and CD8+ T cells in the spleens but showed no clinical evidence of graft-versus-host disease (GVHD). Transfer of allogeneic T cells engrafted in scid recipients did not induce GVHD upon i.v. injection into secondary scid recipients and lead in most recipients to engraftment of a pure CD4+ T-cell population. Experiments were carried out to investigate the reason(s) for the lack of GVHD in recipient scid mice, i.e. the presence of allotolerance in the engrafted donor T cells. Scid spleen cells (SC) efficiently stimulated alloreactive responses of B6 T cells: scid SC stimulated H-2d-specific cytotoxic responses in a B6 anti-scid mixed lymphocyte culture in vitro, and scid SC injected i.v. into B6 mice efficiently primed splenic cytotoxic lymphocyte precursors against H-2d alloantigens. Moreover when assayed in vitro, no veto activity or natural suppressor activity was detectable in scid SC. These data demonstrate that tolerizing mechanisms currently believed to operate in vivo can not explain the fact that allogeneic T cells injected i.v. into immunodeficient scid mice become tolerized against host-type alloantigens. Our results are discussed in the light of clinical experience of allogeneic T-cell transfer in scid infants.

Gravimetric changes in marble and limestone briquettes exposed to outdoor environment at five sites in the eastern United States have been monitored since 1984. An earlier report describes procedures and results obtained in 1984--1988. This report presents the results of the exposure period 1984--1988 and reviews and summarizes those of prior years. A linear relationship was found between cumulative gravimetric losses and exposure period or rain depth. These losses resulted in an average recession rate of 14 to 24 {mu}m/yr for marble and twice that for limestone. Variations in recession among the various exposure sites can be ascribed to differences in rain depth and hydrogen ion concentration. The annual recession rates obtained from gravimetry yielded rates that were for marble twice those obtained from runoff experiments, and more than three times those for limestone; this indicates that physical erosion plays an important role. Gravimetric monitoring of exposed briquettes is continuing in a planned 10-yr program.

Young (less than 3 months of age) and old (greater than 1 year of age) C.B-17 scid/scid mice were tested for the presence of immunoglobulin in serum and CD3+ T cells in spleen and peritoneal cavity. In all old severe combined immune deficiency (scid) mice tested we found detectable, but very variable levels of serum immunoglobulin as well as splenic and peritoneal CD3+ T cells comprising 3% to 10% of the nonfractionated cell populations of these organs (n = 10). In contrast, none of the analyzed young scid mice showed any evidence of peripheral lymphocytes. Low numbers (2 x 10(5) to 5 x 10(5) cells/mouse) of highly purified CD4+ cells from congenic C.B-17 or BALB/c donor mice were injected intravenously into young scid recipient mice. A CD4+ T cell population was clearly engrafted when transplanted scid mice were analyzed 8 to 13 weeks after T cell transfer: (a) a CD3+CD4+CD8- T cell population was detectable in the spleens of all recipient scid mice by flow microfluorometry analyses; (b) CD3+CD4+CD8 T cell lines could be grown out of these spleens in vitro; (c) the histological examination revealed evidence of lymphoid cell repopulation in the spleens of all transplanted scid mice and (d) transplanted CD4+ T cell populations could be serially transferred into secondary and tertiary recipient scid mice. These data indicate that scid mice can be constructed in which only the CD4+ T cell compartment is selectively reconstituted. In contrast to the successful engraftment of CD4+ T cell, highly purified congenic CD8+ T cells could not be engrafted into the spleen of scid mice.

Luxierte Kunstlinsen stellen immer eine Komplikation fur das Auge dar und sollten reponiert werden. Eine inkomplette Vitrektomie via Pars plana mit anschliesender skleraler Nahtfixation der Linsenhaptik im Sulcus ciliaris werden bevorzugt. Der Austausch einer luxierten HKL gegen eine neue HKL oder VKL ist notwendig, wenn die Fixation nicht gelingt. Es wird uber 12 Patienten berichtet.

Side Effects of Water-Soluble Contrast Agents in Upper Gastrointestinal Tract J. GMEINWIESER;W. ERHARDT;H. REIMANN;R. BABIC;U. SPECK;B. WENZEL-HORA; Investigative Radiology

Evidence is presented that early steps in T cell differentiation, to the point of TCR expression, can occur in athymic nude bone marrow (BM) and perhaps also in normal BM. Low density nylon wool nonadherent BM from 5- to 8-wk-old nude and normal mice was found to contain dim CD3+ CD4- CD8- cells. This subpopulation was not found in scid/scid low density nylon wool nonadherent BM but was present at similar frequency in both nude and normal BM and expressed comparable fluorescence intensity. With the use of additional markers, a difference between nude and normal dim CD3+ CD4- CD8- cells was found: the ratio of J11d+/J11d- cells was at least threefold higher in nude than in normal BM. Whereas 60% of nude J11d+ CD3+ cells expressed a TCR-alpha/beta and 40% expressed a gamma/delta TCR, almost no TCR-gamma/delta expressing cells were detected in dim CD3+ cells from normal mice in either the J11d+ or J11d- subpopulation. The majority of those cells express a TCR-alpha/beta. We established that nude dim CD3+ CD4- CD8- cells were distinguishable from mature recirculating T cells and developed an in vitro clonal culture system that supported the growth of these cells. When these cells were cocultured in vitro in a limiting dilution system with inactivated anti-CD3 mAb-secreting cells, in the presence of rIL-2 and rIL-4, one in 5 x 10(2) to 1 x 10(3) cells were growth inducible. Most progeny cells expressed a CD3+ CD8+ CD4- surface phenotype. Cultures displayed nonspecific cytolytic reactivity. With the use of a sensitive dot-blot technique, transcripts coding for C alpha, C beta, VC gamma, and C delta TCR genes were detected in these cultures. Rehybridization experiments demonstrated mutually exclusive expression of either C alpha or C delta mRNA transcripts in the majority of clones selected for a high probability of clonality. Most (greater than 95%) of T cell clones derived from normal BM expressed the C alpha transcript with approximately 5% expressing the C delta transcript. In contrast, about 40% of T cell clones derived from nude BM expressed the C delta transcript whereas the remaining 60% expressed 10-fold lower C alpha message than normal BM-derived clones.

In patients in a surgical intensive care unit a controlled clinical trial was performed concerned with the pathophysiological functions of histamine in stress ulcer disease and with the influence of cimetidine prophylaxis on this complication. The commonly used organization of a controlled clinical trial was enforced to be changed by considerable theoretical, ethical and practical difficulties in designing and conducting the study: As a surprising and remarkable result of the study clinically manifest stress ulcers occurred exclusively in our patients in the intensive care unit and among them mainly in those with severy polytrauma and postoperative complications. Cimetidine was highly effective in preventing stress ulceration in severe polytrauma patients. But it seems absolutely unnecessary to distribute this drug in all patients of a surgical intensive care unit like from a cornucopia of happiness.

In a preliminary study high doses of the H1-antagonist clemastine (clem) and the H2-antagonist cimetidine (cim) were used in order to detect the side effects of both drugs on allergic reactions. After pretreatment with clem or clem/cim different guinea pigs were challenged with either OA or histamine. Bronchial obstruction was measured by body plethysmography using a new parameter ('compressed air'). Pretreatment with clem/cim in high doses protected guinea pigs against OA-induced bronchial obstruction much more effectively than H1-receptor antagonism alone; lower cim doses produced insignificant effects. In histamine-challenged animals cim showed no protective effects. In vitro clem/cim caused a marked reduction of histamine release measured in perfused lungs from 16.9 +/- 4.2 ng/ml (eight control cases) to 2.8 +/- 1.7 ng/ml (n = 8). Our preliminary data suggest that high doses of clem/cim can protect sensitized guinea pigs against allergen-induced bronchial obstruction by inhibiting histamine release.

Microwave and thermal problems in manufacturing high‐power microwave attenuators are considered and some proposals of thick film solutions are presented. Theoretical considerations have been confronted with the results of measurements.

Several preparations of Cremophor El®, several of other non-ionic detergents and several components of Cremophor El were tested for their histamine-releasing capacity in dogs. Lutensol AP 10 and a derivative of 1,2-propylenglycol were ineffective, but showed excellent properties as detergents. Thus the histamine-releasing capacity was not necessarily combined with the tenside effect of the surfactants. Oleic acid found in Tween 80 as well as in Cremophor El seems to be the most effective constituent, but the alcohol seems also to be important for the histamine-releasing capacity. The development of a non-toxic solubilizer for lipophilic drugs seems of considerable clinical interest.

The technical issues, development problems and required experiments and facilities for fusion nuclear technology have been investigated. The results have been used to develop a technical framework for a test plan that identifies the role, timing, characteristics and costs of major experiments and facilities. A major feature of this framework is the utilization of non-fusion facilities over the next 15 years, followed by testing in fusion devices beyond about the year 2000. Basic, separate effect and multiple interaction experiments in non-fusion facilities will provide property data, explore phenomena and provide input to theory and analytic modelling. Experiments in fusion facilities can proceed in two phases: (1) concept verification and (2) component reliability growth. Integrated testing imposes certain requirements on fusion testing device parameters; these requirements have been quantified. The nuclear subsystems addressed in the study are: (a) blanket and first wall; (b) tritium processing system; (c) plasma interactive components; and (d) radiation shield. The two generic classes of liquid and solid breeder blankets have significant engineering feasibility issues, and new experimental data must be obtained before selection of an attractive design concept. Liquid metal blanket issues are dominated by problems related to momentum, heat and mass transfer, which can be addressed in non-neutron test facilities. Solid breeder blanket issues are, however, dominated by the effects of radiation, including heating, transmutation and damage, which can be reasonably addressed in fission reactors. The tritium processing uncertainties are primarily related to the control and recovery systems, and most can be addressed in existing and planned non-neutron facilities. A dominant feature of plasma interactive components is the strong interrelation to both plasma physics and nuclear technology. Required facilities include thermomechanical test stands and confinement devices with sufficiently long plasma burn. The radiation shield poses no feasibility issues, but improved accuracy of predictions will reduce design conservatism and lower costs.

Small breaks at the bottom, the top or the side of a horizontal coolant pipe with stratified flow are investigated. The accurate prediction of the mass flux and quality through such breaks is of great importance in nuclear reactor safety research. Experiments were performed with air-water flows through breaks simulated by pipe stubs of various diameters, perpendicular to a horizontal main pipe. The flow phenomena observed are illustrated with photographs. Correlations are given for the beginning of entrainment. Measurements of the break quality and mass flux were made for various values of the interface level and of the pressure difference between main pipe and break outlet. A model was developed to predict the break quality and mass flux and an example is presented to apply the model to steam-water critical branch mass flux.

Phase separation was measured in air-water and steam-water mixtures flowing through a T- junction with equal pipe diameters ( d = 50 mm ) and a horizontal, vertical upward or vertical downward branch. The flow parameters were varied over a wide range to generate a variety of inlet flow patterns. The degree of phase separation depends significantly on the branch orientation, the inlet flow pattern and the ratio of inlet mass flux to branch mass flux. Empirical correlations for the phase separation for the different branch orientations have been derived.

The ability of F1 (H-2k/d) responder cells to generate cytotoxic effector cells against parental and F1 targets was investigated under limiting dilution conditions. One hit limiting dilution curves, consistent with the generated cytolytic cells being the progeny of a single precursor cell, were reproducibly obtained if a culture was scored as "responding" on the basis of its ability to lyse one or more of a panel of Con A blast targets consisting of self F1 and both parents. The calculated frequency of the precursor cell in a nylon wool-nonadherent splenic responder cell population ranged from about 1/500 to 1/1600 in (B10.BR X B10.D2)F1 and (RNC X BALB/c)F1 mice. The patterns of lysis expressed by individual microcultures against the panel of F1 and both parental targets were unusual; besides patterns that were consistent with predictions of classic transplantation rules (i.e., lysis of F1 targets plus one/both parental targets), "anomalous" patterns (i.e., lysis of F1 targets or one/both parental targets exclusively) were also seen. The precursor cells that gave rise to cytolytic cells were devoid of T cell markers, whereas the cytolytic effector cells were Thy-1+, Lyt-2+, as defined by sensitivity to treatment with monoclonal antibody plus complement. The data are discussed in the context of early in vitro development of cytolytic T lymphocytes, with particular emphasis on a possible manifestation of an early T cell repertoire.

The pressure differences between pipe inlet and run, Δp 1−2 , and inlet branch, Δp 1−3 , were measured for air—water and steam—water flow in a T- junction with equal diameters and a horizontal, vertical upward or downward branch. The experimental results are compared with those previously published and a model presented herein. The agreement is good for the horizontal and vertical downward branch; however, no model predicts satisfactorily the pressure drop in the upward branch flow.

The cytotoxic response of splenic Lyt-2+ T cells to class I H-2 alloantigen-bearing stimulator cells was analyzed under limiting dilution conditions. One of 50 to one of 200 nylon wool-nonadherent (FACS-purified), small Lyt-2+ spleen cells of B6 origin gave rise in vitro to a cytotoxic T lymphocyte clone that specifically lysed targets bearing bm1 alloantigen. This population of alloantigen-specific cytotoxic lymphocyte precursors (CLP) was activated by different types of bm1 stimulator cells with different efficiency: 2 X 10(5) nonfractionated spleen cells, 5000 normal peritoneal cells, 400 to 10(4) L3T4+ helper T blasts, or 2000 to 10(4) Lyt-2+ T blasts induced clonal growth of this CLP pool. Irradiated or mitomycin-treated small (L3T4+ or Lyt-2+) bm1-derived T cells were inefficient stimulator cells for this response. Supplementation of culture medium with (recombinant) interleukin 2 was necessary and sufficient to support clonal development of alloantigen-triggered CLP in the presence of allogeneic T blasts. Under these limiting dilution conditions, we observed comparable cloning efficiencies for (wild-type) Kb-allospecific splenic Lyt-2+ CLP from bm1 mice generated in response to either irradiated B6 spleen cells or inactivated B6-derived T cell lines (EL4 and RBL-5 lymphoma cells). The data indicate that normal T lymphoblasts as well as tumor T cell lines stimulate clonal development in vitro of class I H-2-allospecific cytotoxic T lymphocytes in the presence of interleukin 2.

Many experiments being conducted to investigate the hypothesized loss-of-coolant accident (LOCA) in nuclear power plants involve the measurement of two-phase flow. This paper describes an experiment conducted to determine the behavior of a drag-disc turbine transducer (DTT) in a high pressure, high temperature, steam-water steady state environment. DTTs have been used extensively to measure mass flow rates in the Loss-of-Fluid-Test (LOFT) experiments. Drag discs and turbines have been used in many other safety related facilities. However, the performance of these instruments is highly dependent on flow regime and void fraction and this dependence makes data analysis difficult. Experiments conducted in separated flow are described in this paper. The results show the measured mass flow rates can be corrected if a three-beam gamma densitometer is available, if the calculated density ratio correction is less than three, and if the velocity measured by the turbine is greater than 2 m/ s. The results also suggest that the turbine and drag disc measure local mass average quantities averaged over the area of the DTT.

In fourteen patients with food allergy, intragastral provocation under endoscopical control (IPEC) was performed. In all patients positive immediate-type reactions of the gastric mucosa were observed consisting of oedema, erythema and petechial bleeding. Microscopically, mast cell degranulation was observed and measured by mast cell counts using the o-phthaldialdehyde technique. Concomitantly, tissue histamine content in gastric mucosa decreased significantly after allergen provocation, while there was no change in normal volunteers. Plasma histamine concentration increased in most patients; the increases were most evident in four patients showing mild systemic reactions (urticaria and bronchospasm). The technique described might prove to be useful in establishing the diagnosis in doubtful cases of food allergy.

Intravenous urography using Telebrix was performed on 500 patients. Two hundred patients (group I) received no pre-medication; 300 patients (group II) were premedicated with H1 and H2 receptor antagonists. All patients were examined for signs of contrast reactions, blood pressure, pulse rate and plasma histamine levels. These were measured before and three minutes after the administration of the antihistamine substances and/or the contrast medium, and also at the end of the examination. Following the administration of H1 and H2 receptor antagonists, a slight, transient and insignificant rise in plasma histamine could be demonstrated. Both groups showed a significant rise in plasma histamine levels after the injection of the contrast medium. Although the pre-medicated group contained a higher percentage of high risk patients, there were significantly fewer patients with contrast reactions. Pre-medication with H1 and H2 receptor antagonists in high risk patients is therefore advisable.