Maturation and refinement of the maculae and foveae in the Anolis sagrei lizard.

The fovea is a pit in the center of the macula, which is a region of the retina with a high concentration of photoreceptor cells, which accounts for a large degree of visual acuity in primates. The maturation of this primate visual acuity area is characterized by the shallowing and widening of the foveal pit, a decrease in the diameter of the rod-free zone, and an increase in photoreceptor cells packing after birth. Maturation occurs concurrently with progressing age, increasing eye size, and retinal length/area. These observations have led to the hypothesis that the maturation of the fovea might be a function of mechanical variables that remodel the retina. However, this has never been explored outside of primates. Here, we take advantage of the Anolis sagrei lizard, which has a bifoveated retina, to study maturation of the fovea and macula. Eyes were collected from male and female lizards-hatchling, 2-month, 4-month, 6-month, and adult. We found that Anolis maculae undergo a maturation process somewhat different than what has been observed in primates. Anole macular diameters actually increase in size and undergo minimal photoreceptor cell packing, possessing a near complete complement of these cells at the time of hatching. As the anole eye expands, foveal centers experience little change in overall retina cell density with most cell redistribution occurring at macular borders and peripheral retina areas. Gene editing technology has recently been developed in lizards; this study provides a baseline of normal retina maturation for future genetic manipulation studies in anoles.

Asymmetric band gap shift in electrically addressed blue phase photonic crystal fibers.

In this paper, we present electrooptic experiments on photonic crystal fibers filled with a liquid crystalline blue phase. These fibers guide light via photonic band gaps (PBGs). The blue phase is isotropic in the field-off state but becomes birefringent under an electric field. This leads to a polarization dependent shift of the PBGs. Interestingly, the effect on the PBGs is asymmetrical: while the short wavelength edges of the PBGs shift, the long wavelength edges are almost unaffected. By performing band gap and modal analyses via the finite element simulations, we find that the asymmetric shift is the result of the mixed polarization of the involved photonic bands. Finally, we use the band gap shifts to calculate effective Kerr constants of the blue phase.

[Novel immunodiagnostics for inflammatory arthritis]. / Neue Immundiagnostik bei Arthritiden.

Immunodiagnostics play an important role in the differential diagnostics of arthritis but the test results must be interpreted with respect to the clinical context. The detection of antibodies against citrullinated proteins has significantly improved the immunodiagnostics of arthritis, whereas the importance of testing for rheumatoid factor has decreased due to the low specificity. Antibodies against carbamylated or oxidized proteins will expand the immunodiagnostics of arthritis (especially rheumatoid arthritis) in the future. In contrast, the determination of cytokine concentrations in plasma or synovial fluid plays a subordinate role in the differential diagnostics of arthritis. Indirect immunofluorescence continues to be the gold standard in the detection of antinuclear antibodies (ANA) and in the case of positive results further testing for antigen specificity should be carried out. The presence of ANA is not necessarily associated with autoimmune diseases. An example of a non-pathogenic ANA is anti-DFS70 antibodies.

Liquid crystal assisted optical fibres.

Microstructured fibres which consist of a circular step index core and a liquid crystal inclusion running parallel to this core are investigated. The attenuation and electro-optic effects of light coupled into the core are measured. Coupled mode theory is used to study the interaction of core modes with the liquid crystal inclusion. The experimental and theoretical results show that these fibres can exhibit attenuation below 0.16 dB cm(-1) in off-resonant wavelength regions and still have significant electro-optic effects which can lead to a polarisation extinction of 6 dB cm(-1).

[Bitemporal scalp necrosis : a very rare manifestation of giant cell arteritis]. / Bitemporale Skalpnekrose : Eine sehr seltene Manifestation der Riesenzellarteriitis.

A 71-year-old woman developed progressive spreading of bitemporal scalp necrosis within 4 weeks accompanied by headaches, myalgia of the shoulder girdle and muscle weakness that had started a few months previously. No additional diseases were reported. The suspected temporal giant cell arteritis could be confirmed by temporal artery biopsy. Therapy with glucocorticoids led to a rapid resolution of clinical symptoms and was tapered over 18 months. Recovery of the scalp necrosis emerged following second intention healing and split-skin transplantation of necrotic areas after successful wound conditioning. The case study demonstrates a rare and serious complication of temporal arteritis which is often accompanied by a poor prognosis.

[Anemia in patients with rheumatoid arthritis]. / Anämie bei Patienten mit rheumatoider Arthritis.

One of the most frequent extra-articular organ manifestations in rheumatoid arthritis (RA) is anemia. As anemia in RA patients may result in severe symptoms and aggravation of other disease manifestations (e.g. arteriosclerosis), the influence on the course of RA is profound. However, the importance of anemia in RA patients is frequently underestimated. The etiology of anemia in RA is complex. Anemia of inflammation (AI) and iron deficiency anemia, alone or in combination are the most frequent forms of anemia in RA. Changes in iron metabolism are the leading causes of anemia in RA patients and mainly induced by the altered synthesis and function of hepcidin and ferroportin. Hepcidin, a peptide produced in the liver and immunocompetent cells, impairs the expression of ferroportin on iron-secreting cells, thus reducing iron bioavailability. The typical changes of iron metabolism and hepcidin synthesis in RA are induced by proinflammatory cytokines, primarily interleukin-6. Hence, the treatment of RA with cytokine antagonists has significant therapeutic implications on anemia in the context of inflammation and impaired iron metabolism.

Corticotropin releasing hormone (CRH) response in patients with early rheumatoid arthritis due to polymorphisms in the CRH gene.

OBJECTIVES: To further evaluate the impact of corticotropin releasing hormone (CRH) promoter polymorphisms on the stress response in rheumatoid arthritis (RA) patients an insulin hypoglycaemia test (IHT) was performed studying the dynamics of CRH production. METHODS: Polymorphisms of the human CRH promoter were determined in controls and cortisol naive patients with early RA. Serum glucose and plasma CRH were measured at baseline and up to 120 min following induction of hypoglycemia. RESULTS: During IHT RA patients bearing the A2B2 allele exhibited an earlier CRH response compared to A1B1 positive patients. CONCLUSIONS: Stress-induced response of CRH is differentially modulated by CRH promoter polymorphisms in RA patients.

[Rare cause of acute liver failure]. / Seltene Ursache eines akuten Leberversagens.

A rare cause of acute liver failure is adult onset Still's disease (AOSD), a systemic inflammatory disorder. We present the case of a 24-year-old woman who presented with acute liver failure necessitating high urgency liver transplantation. The diagnosis of AOSD was established in accordance with the Yamaguchi classification criteria, including arthralgia, fever, sore throat, rash and hepatosplenomegaly. The early detection and therapy of AOSD can possibly avoid the development of liver failure with a poor prognosis.

Association between beta2 adrenergic receptor polymorphisms and rheumatoid arthritis in conjunction with human leukocyte antigen (HLA)-DRB1 shared epitope.

OBJECTIVE: In the present work, the frequency of inherited polymorphisms of the beta2 adrenergic receptor (beta2AR) gene and their association with rheumatoid arthritis (RA) as well as human leukocyte antigen (HLA)-DRB1 alleles was examined. METHODS: An allele-specific polymerase chain reaction was used to determine the common variants of the beta2AR at positions 16, 27 and 164 in patients with RA (n=310) and ethnically matched healthy controls (n=305) from Germany. HLA-DRB1 genotyping was performed by oligonucleotide hybridisation of enzymatically amplified DNA allowing low-resolution HLA-DRB1 genotyping comprising specificities DRB1*01 to DRB1*17. RESULTS: Arginine (Arg) at codon 16 was present in 278 patients with RA (89.7%) compared to 202 controls (66.2%; odds ratio (OR) 4.43, 95% CI 2.81 to 7.02, p<0.001). Homozygosity for Arg16 was found in 107 patients with RA (34.5%) compared to 14 controls (4.6%; OR 10.9, CI 5.9 to 20.5, p<0.001). Stratifying patients for their HLA-DR status revealed that homozygosity for Arg16 exhibited the greatest risk for RA in combination with HLA-DRB1*04 (OR 17.1, 95% CI 1.71 to 414.4, p=0.004). Interestingly, patients with the Arg16 allele have a younger mean (SD) age at disease onset compared to patients without Arg16 (46.1 (2.0) vs 53.1 (2.7) respectively, p<0.05). Furthermore, 93.3% patients with homozygosity for Arg16 were positive for anti-cyclic citrullinated peptide (CCP) antibodies vs 75% patients with homozygosity for Gly16 (p<0.05). CONCLUSION: There was a highly significant distortion between patients with RA and controls in the distribution of beta2AR polymorphisms at codon 16, contributing (together with the HLA-DR alleles) to the genetic background of RA.

Promoter polymorphisms regulating corticotrophin-releasing hormone transcription in vitro.

To investigate whether polymorphisms in the corticotrophin-releasing hormone (CRH) promoter are associated with altered CRH gene regulation, we studied the reactivity of three recently described promoter variants in vitro. The 3625 bp variants A1B1, A2B1 and A2B2 of the human CRH promoter were cloned in the 5' region to a luciferase reporter gene and transiently transfected into both mouse anterior pituitary cells AtT-20D16vF2 and pheochromocytoma cells PC12. Incubation with 8-Br-cAMP alone or in combination with cytokines significantly enhanced the promoter activity in both cell lines studied by up to 22-fold. However, dexamethasone antagonised cAMP effects on CRH expression in AtT-20 cells while showing no effect on PC12 cells, indicating that tissue-specific factors play a crucial role. Among the haplotypes studied, A1B1 exhibited the greatest reactivity on various stimuli. Electric mobility shift assay (EMSA) was performed to study whether the described polymorphic nucleotide sequences in the 5' region of the hCRH gene interfere with binding of nuclear proteins. A specific DNA protein complex was detected at position -2353 bp for the wild type sequence only, possibly interfering with a binding site for the activating transcription factor 6 (ATF6). Taken together, this is the first study to demonstrate that CRH promoter reactivity varies between the compound promoter alleles.

Beta2-adrenergic receptors mediate the differential effects of catecholamines on cytokine production of PBMC.

We determined characteristics of beta2-adrenergic receptors (beta2R) on peripheral blood mononuclear cells (PBMC) and cytokine production after mitogenic stimulation and coincubation with catecholamines. PBMCs were stimulated with interleukin-2 (IL-2), tetanus toxoid (TT), anti-CD3 antibody, or phytohemagglutinin (PHA). The cytokines interferon-gamma (IFN-gamma), IL-4, and IL-6 were determined by ELISA following coincubation with high-dose (10(-5) M) and low-dose (10(-9) M) epinephrine (EPI) and norepinephrine (NE). Intracellular IFN-gamma and IL-4 were studied by FACS analysis. The beta2R density was investigated using a radioligand binding assay. The stimuli induced various cytokine profiles in PBMCs. Synthesis of IFN-gamma was induced by all mitogens and could be suppressed by catecholamines (26%-85% reduction). In PHA-stimulated PBMCs, IL-4 synthesis was decreased by high-dose catecholamines (24%-28% reduction). Adding a beta-blocking agent attenuated most catecholamine effects. A highly significant negative correlation between the density of beta2R with IFN-gamma and IL-6 levels of PHA-activated PBMCs (r = -0.88 to -0.96, p < 0.01-< 0.001) was observed. The results indicate that the density of beta2R on PBMC plays a role in mediating the differential catecholamine effects on cytokine production of PBMC. Furthermore, changes in cytokine expression induced by catecholamines favor Th2 responses.

Immunopathogenesis of rheumatic diseases in the context of neuroendocrine interactions.

Growing evidence supports the hypothesis that alterations of the stress response and interactions between the neuroendocrine and immune systems contribute to the pathogenesis of rheumatic diseases such as rheumatoid arthritis (RA). In particular, the hypothalamus-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS) are of special interest. Polymorphisms of the corticotropin-releasing hormone (CRH)-regulating region have been described recently. These polymorphisms are differentially distributed in RA patients and healthy subjects of various ethnic origin, thus supporting the hypothesis that they represent a new genetic marker for RA susceptibility. The decreased expression of beta(2)-adrenergic receptors (beta(2)-R) on lymphatic cells in rheumatic diseases like RA, together with an impaired influence of catecholamines on immune function in these patients, further underlines the concept of a dysfunction of the ANS in rheumatic diseases. Results from work in this field will provide more insight into the pathogenesis of RA and help to establish novel therapies for this chronic rheumatic disease.

Decreased catecholamine-induced cell death in B lymphocytes from patients with rheumatoid arthritis.

The expression of beta2-adrenergic receptors (beta2-R) on B lymphocytes and agonist-induced cAMP production is reduced in patients with rheumatoid arthritis (RA). To further study functional consequences of the diminished beta2-R density on B lymphocytes in RA patients, agonist-induced cell death was evaluated and compared to healthy controls. B lymphocytes from patients with RA and healthy controls were activated with anti-IgM-antibody. Coincubation was carried out with isoprenaline (iso, 0.001-10 microM). Apoptotic and necrotic cells were determined using Annexin-V and propidium-iodide staining. beta2-R-induced cell death in B cells from healthy volunteers was stimulated after 24 h (medium, 21.2 +/- 1.6%; iso, 34.6 +/- 4.4%; increase 59.3 +/- 10.1%). However, in RA patients the increase in cell death following beta2-R stimulation (21.8 +/- 8.9%) was significantly impaired (p = 0.02). Our data demonstrate that catecholamine-induced cell death after stimulation of beta2-R on B lymphocytes is decreased in RA patients, possibly contributing to the pathogenesis of the disease.

[Neuroendocrine-immunologic mechanisms in rheumatic diseases--a congress report]. / Neuroendokrine-immunologische Mechanismen bei rheumatischen Erkrankungen--Ein Kongressbericht.

Neuro-endocrine immune mechanisms play an important immunomodulatory role for rheumatic diseases as evidenced by long-recognized effects of glucocorticoids, gender, pregnancy, hemiparalysis, and stress on various clinical and epidemiological aspects. Recently, some regulatory pathways have been identified between the neuroendocrine and immune systems which seem to be altered in these diseases. Cooperation between the autonomic nervous system and the hypothalamic pituitary adrenal axis (HPA axis) is important to dampen the reaction of the immune system. In chronic inflammatory diseases such as rheumatic diseases these systems have become deficient. Moreover, hyperexcitability of sensory nerves due to peripheral and central neuronal sensitization can support the local inflammatory process.

Noncompliance of health care workers with universal precautions during trauma resuscitations.

BACKGROUND: Universal precautions during resuscitations are mandated by hospital regulations. We documented adherence to universal precautions during trauma resuscitations at our level I trauma center. METHODS: During trauma resuscitations, a medical student using an elevated viewing platform observed health care workers (HCWs) for the use of barrier precautions (BPs): gloves, masks, gowns, and eyewear. Only HCWs having direct patient contact were included. The purpose of the observation was not disclosed to those being observed. RESULTS: In 12 resuscitations involving 104 HCWs, none had 100% compliance with BPs. Compliance rates for individual BPs were gloves, 98%; eyewear (any type), 52%; gowns, 38%; masks, 10%; and eyewear (with side protectors), 9%. Resuscitations in which bleeding was observed involved 59 HCWs with 38% compliance; only 2 used full BPs. No difference in compliance rates occurred during the study period. CONCLUSIONS: Experienced trauma care HCWs are cavalier regarding blood-borne disease exposure risks. Measures to encourage (or force) compliance are needed.

Impaired catecholaminergic signalling of B lymphocytes in patients with chronic rheumatic diseases.

OBJECTIVE: To investigate further the influence of the autonomic nervous system on chronic rheumatic diseases. METHODS: The density and affinity of beta2 adrenergic receptors (beta2R) on CD19+ lymphocytes in patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and systemic sclerosis (SSc), as well as intracellular cAMP levels in patients with RA and SLE, were determined. Human peripheral blood mononuclear cells were separated from venous blood of patients and healthy controls by Ficoll-Hypaque density centrifugation. CD19+ lymphocytes were purified by magnetic cell sorting, and beta2R were determined by a radioligand binding assay with [125I]iodocyanopindolol. Intracellular cAMP levels and beta2R agonist induced cell death were measured by a radioimmunoassay and flow cytometry using annexin-V binding, respectively. Systemic disease activity of the patients was evaluated using multifactorial scoring systems. RESULTS: The density of beta2R on peripheral CD19+ lymphocytes was significantly decreased in patients with RA, SLE, and SSc compared with healthy controls. In patients with RA and SSc beta2R density was negatively correlated with systemic disease activity. Furthermore, although basal intracellular cAMP levels were raised in patients with RA and SLE, the increase of cAMP upon stimulation of beta2R was significantly reduced in these patients compared with control subjects. Preliminary data suggest that beta2R agonist induced cell death is diminished in patients with RA exhibiting decreased beta2R densities. CONCLUSIONS: The results of this study show a reduction of beta2R densities on B lymphocytes mirrored by an impaired intracellular cAMP generation in patients with chronic rheumatic diseases, indicating a decreased influence of the autonomic nervous system on B cells in these conditions.

Regulation of beta2-adrenergic receptors on CD4 and CD8 positive lymphocytes by cytokines in vitro.

Increasing evidence points to a close relationship between the autonomic nervous system and the immune system. To further investigate mechanisms regulating beta2-adrenergic receptor (beta2R) expression in lymphocytes, the influence of cytokines on the density of beta2R on purified CD4+ and CD8+ lymphocytes was determined in vitro. beta2R were determined by means of a radioligand binding assay with (125I)iodocyanopindolol. CD4+ and CD8+ lymphocytes were incubated with catecholamines, interleukin 1beta (IL-1beta) and interleukin 2 (IL-2) for 6-72 h. The results demonstrate declining beta2R numbers on CD4+ and CD8+ lymphocytes in vitro augmented by epinephrine. IL-1beta has no effect on beta2R expression compared to medium. However, incubation with IL-2 resulted in an up-regulation of beta2R on CD8+ lymphocytes. Thus, the study demonstrates a differential regulation of beta2R on T-lymphocyte subpopulations with CD8+ lymphocytes being more susceptible to mechanisms of beta2R modulation than CD4+ lymphocytes. The findings further strengthen the concept of a close interplay between the autonomic nervous system and the immune system.