Monitoring of laying capacity, immunoglobulin Y concentration, and antibody titer development in chickens immunized with ricin and botulinum toxins over a two-year period

One of the key benefits in using chickens for immunization is the high yield of antibodies obtainable. It is known that egg production decreases over time, while animal maintenance costs remain stable. It would, however, be desirable to keep hens as long as possible to obtain maximal amounts of antibodies. To identify a suitable length of time that animals can be kept and to optimize the cost:yield ratio, we monitored the number of eggs laid, the total amount of chicken IgY, and the specific antibody titer from individually prepared eggs over a 2-yr period. The plant toxin ricin and the Clostridium botulinum neurotoxins type A and B were used to immunize 4 chickens. The number of eggs laid in 2 yr was approximately 600 per hen (about 80% of the maximum egg number), yielding about 20 to 40 g of total IgY per hen. A stable antibody titer of 1:100,000 to 1:1,000,000, as measured by ELISA, was obtained following up to 11 injections of 10 to 20 microg of immobilized native toxin. Laying capacities were found to decrease, on average, from 7 eggs/wk at the point of first immunization to 2 eggs/wk after more than 2 yr. In parallel, the yield of total and specific IgY increased over time, so that the antibody recovery remained high, even after prolonged immunization times. Using purified IgY preparations, classical immunological assays such as ELISA and Western blotting were performed. Furthermore, the IgY showed neutralizing capacity when used to block the functional activity of the toxins both in vitro and in vivo. Analysis of the total IgY content over time demonstrated a complex biological oscillation (and the antigen-specific titer), with a shorter time period of around 7 d (circaseptan rhythm). In summary, we successfully immunized chickens with ricin and botulinum neurotoxins and monitored laying capacity, IgY concentration, and specific antibody titer over an extended period of 2 yr.

Brillouin neutron scattering in heavy water: evidence for two-mode collective dynamics

A high resolution (1.5 meV) inelastic neutron scattering experiment was carried out, aiming at an accurate investigation of the high frequency and low momentum dynamic response in heavy water. The experimental data confirm the existence of a dispersionless mode, besides the ordinary longitudinal collective dynamics. A simplified model, based on the interaction of two vibrational branches, is proposed to interpret the observed features of the dynamic spectra. The validity extent of this scheme is proved by applying it to room temperature neutron and x-ray data, to temperature and pressure dependent x-ray data, and to room temperature neutron data of vibrational density of states. The overall successfull results provided by this model, in conjunction with the combined analysis of the x-ray and neutron data on collective dynamics, enable a deeper insight into the complex mechanisms of the water dynamics and provide a simple phenomenological explanation for the transition from ordinary to fast sound.

Structure and properties of confined sodium nitrite

The temperature evolution of the structure of NaNO(2) nanocomposite ferroelectric material in a porous glass with 7 nm pores was studied by neutron diffraction in temperature region from room temperature up to the melting, i.e. in the ferro- and paraelectric phases. It is demonstrated that in the ferroelectric phase the structure is consistent with the structure of the bulk, but above the ferroelectric phase transition (and up to approximately 513 K) a volume premelted state is formed, manifesting itself in a growth of amplitudes of ion thermal vibrations, a steep increase of elementary cell volume and "softening" of lattice. For the first time the temperature dependence of order parameter eta for confined sodium nitrite is determined. eta (T) follows a power law with T(C)=425.6+/- 2.1 K and beta= 0.31+/- 0.04, which is essentially different from that for bulk NaNO(2). Our obtained data are in a good agreement with the results of earlier dielectric and neutron diffraction measurements.

Neutron investigation of the ion dynamics in liquid mercury: evidence for collective excitations

The ion dynamics of liquid mercury was investigated by inelastic neutron scattering. By exploiting an optimized high-resolution ( approximately 1 meV) experimental configuration, the dynamic response function was accurately measured. Collective excitations extending up to 0.6 A(-1) were observed with an associated velocity of 2100+/-80 m/s. This value is notably greater than the sound velocity, but it is provided by a simple Bohm-Staver calculation. The latter finding emphasizes those electron-related features in the ion dynamics, which are common to systems as different as polyvalent and alkali metals.

Heat shock proteins as "danger signals": eukaryotic Hsp60 enhances and accelerates antigen-specific IFN-gamma production in T cells

The heat shock proteins (HSP) gp96, Hsp70 and Hsp60 activate professional antigen-presenting cells (APC) to secrete proinflammatory cytokines and to express costimulatory molecules. Here, we analyze the impact of Hsp60 as a hypothetical danger signal on the antigen-specific activation of T cells derived from DO11.10 TCR-transgenic mice. The release of IFN-gamma, induced by the antigenic OVA(323-339)-peptide, is increased and accelerated dramatically by the addition of Hsp60 to ex vivo purified populations of T cells and peritoneal macrophages (PEC), while the antigen-specific IL-2 production or proliferation of the T cells remain unchanged. In contrast, "effector" T cells, undergoing secondary stimulation, displayed almost unchanged activation kinetics in the presence of Hsp60. The presence of Hsp60 induces IFN-gamma and up-regulation of CD69 in T cell/PEC cocultures even in the absence of antigenic peptide and this induction of IFN-gamma is strictly dependent on the ability of the macrophages to produce IL-12. Taken together, our data strongly suggest that the presence of eukaryotic mitochondrial Hsp60 allows antigen-specific IFN-gamma secretion under conditions when an antigenic stimulus alone is not sufficient to activate T cells.

Heat shock proteins as "danger signals": eukaryotic Hsp60 enhances and accelerates antigen-specific IFN-gamma production in T cells

The heat shock proteins (HSP) gp96, Hsp70 and Hsp60 activate professional antigen-presenting cells (APC) to secrete proinflammatory cytokines and to express costimulatory molecules. Here, we analyze the impact of Hsp60 as a hypothetical danger signal on the antigen-specific activation of T cells derived from DO11.10 TCR-transgenic mice. The release of IFN-gamma, induced by the antigenic OVA(323-339)-peptide, is increased and accelerated dramatically by the addition of Hsp60 to ex vivo purified populations of T cells and peritoneal macrophages (PEC), while the antigen-specific IL-2 production or proliferation of the T cells remain unchanged. In contrast, "effector" T cells, undergoing secondary stimulation, displayed almost unchanged activation kinetics in the presence of Hsp60. The presence of Hsp60 induces IFN-gamma and up-regulation of CD69 in T cell/PEC cocultures even in the absence of antigenic peptide and this induction of IFN-gamma is strictly dependent on the ability of the macrophages to produce IL-12. Taken together, our data strongly suggest that the presence of eukaryotic mitochondrial Hsp60 allows antigen-specific IFN-gamma secretion under conditions when an antigenic stimulus alone is not sufficient to activate T cells.

Neutron investigation of collective excitations in liquid K-Cs alloys: the role of the electron density

The investigation of the ion dynamics in the liquid alloy K52Cs48, which has the same electron density as Rb, was carried out by neutron inelastic scattering. Well defined collective excitations were observed up to the maximum value of momentum transfer of the experiment. A scaling of the dispersion relation data was found to hold between K-Cs alloys, Rb and Cs. The suggested scaling points out the key role of the conduction electron density in the collective dynamics of alkali metals.

High-resolution neutron scattering measurement of the dynamic structure factor of heavy water

The low momentum collective dynamics of heavy water has been investigated by means of neutron three-axis spectroscopy. Working at the resolution limit of this instrument, an energy resolution of 2.6 meV was achieved for a constant analyzer energy of 120 meV. This good resolution allowed us to establish definitely that the collective dynamics of water is dominated by the presence and interaction of opticlike and acousticlike branches, coupling at wave-vector transfers of 0.3 to 0.35 A(-1). The transition from slow to fast sound has been attributed to the interaction between opticlike modes and a solidlike fast acoustic mode.

Pulmonary Rhizopus infection in a diabetic renal transplant recipient

Infectious complications after renal transplantation remain a major cause of morbidity and mortality. Mucormycosis is a rare infection in renal transplant recipients; however, mortality is exceedingly high. Risk factors predisposing to this disease include prolonged neutropenia, diabetes, and patients who are immunosuppressed (Singh N, Gayowski T, Singh J, Yu LV. Invasive gastrointestinal zygomycosis in a liver transplant recipient: case report and review of zygomycosis in solid-organ transplant recipients, Clin Infect Dis 1995: 20: 617). Life-threatening infections can occur, as this fungus has the propensity to invade blood vessel endothelium, resulting in hematological dissemination. We report a case of cavitary Rhizopus lung infection, 2 months after renal transplantation, where the patient was treated successfully with Amphotericin B and surgical resection of the lesions with preservation of his allograft function. In this era of intensified immunosuppression, we may see an increased incidence of mucormycosis in transplant population. Invasive diagnostic work-up is mandatory in case of suspicion; Amphotericin B and, in selected cases, surgical resection are the mainstays of therapy.

The "to feed or not to feed" dilemma

Advance directives can promote and improve communication between the patient and the provider and ideally safeguard the resident's interests by directing medical care. Participation on the facility's ethics committee allows the dietitian to become involved in the legal and ethical issues regarding feeding and to promote the use of specific advance directives for nutrition and hydration. Consider the goals of patient care carefully and assure that they are individualized and patient-centered. Continually reassess nutritional status and collaborate with the health care team in recommending interventions and care plans for each case.

Purification, structural analysis, and function of natural ATAC, a cytokine secreted by CD8(+) T cells

Recently, we identified a novel putative human cytokine expressed by activated CD8(+) T cells, which was designated ATAC (activation-induced, T cell-derived, and chemokine-related; the same molecule has been identified independently as lymphotactin and single cysteine motif-1). In this report, we provide evidence that ATAC is a secreted 93-amino acid protein that is generated from its precursor by proteolytic cleavage between Gly21 and Val22. An estimated 60% of ATAC (Val22-Gly114) is secreted as an unmodified protein with a molecular mass of 10,271.72 Da (apparent molecular mass of 12 kDa in SDS-polyacrylamide gel electrophoresis) and in which Cys32 and Cys69 are linked by a disulfide bridge. Unmodified ATAC is a cationic protein with a pI of 11.35 and is capable of binding to heparin. Some 40% of ATAC is O-glycosylated within 25 min of synthesis, giving rise to the appearance of a homogeneous 15-kDa (minor fraction) and a heterogeneous, terminally sialylated 17-19-kDa (major fraction) protein species in SDS-polyacrylamide gel electrophoresis. The secretion of all ATAC protein variants is completed within 30-40 min of synthesis. In terms of function, various ATAC protein forms were consistently ineffective in chemotaxis assays. In contrast, both purified natural ATAC and a chemically synthesized aglycosyl analog induced locomotion (chemokinesis) in purified CD4(+) and CD8(+) T cell populations at 400 ng/ml.

Cloning of ATAC, an activation-induced, chemokine-related molecule exclusively expressed in CD8+ T lymphocytes

A cDNA clone, designated ATAC, was isolated from a collection of human T cell activation genes. Analysis of tissue distribution determined that ATAC mRNA of approximately 0.9 kb is exclusively expressed in activated CD8+ T cells. Induction of the ATAC gene requires stimulation by both phorbol 12-myristate 13-acetate and Ca2+ ionophore A23187 ("two-signal gene") and is fully abrogated by the immunosuppressive agent cyclosporin A. Upon stimulation, ATAC mRNA is detectable within 30 min, maximal expression is seen after 4 h. The polypeptide encoded by the open reading frame of ATAC mRNA is 114 amino acids long with a calculated M(r) of 12.52 kDa. The structural features predict the cleavage and secretion of a mature ATAC protein of approximately 10 kDa from the 12.52-kDa precursor. ATAC is highly similar to a very recently identified murine molecule designated lymphotactin both at the cDNA (73.8% identity) and the protein (61.4% identity) levels, and related to members of the C-C and C-X-C chemokine families. Two variants of the ATAC protein were expressed and tested for chemotaxis and Ca2+ release on a variety of target cells. The ATAC gene was located to chromosome 1q23.

Transforming growth factor-beta relieves stem cell factor-induced proliferation of myelogenous leukemia cells through inhibition of binding of the transcription factor NF-jun

Transforming growth factor-beta (TGF-beta) is a potent inhibitor of growth factor-stimulated hematopoiesis in normal and leukemic conditions. Using the factor-dependent myelogenous leukemia cell lines GF-D8 and Mo7, we show that TGF-beta interferes with stem cell factor (SCF)-induced proliferation by downmodulating c-jun gene expression. The ability of SCF to induce accumulation of c-jun transcripts was abolished when TGF-beta was present in culture. Transcriptional nuclear run-on assays indicated that TGF-beta relieved the capacity of SCF to enhance the transcriptional rate of the c-jun gene. Deletion analysis of the c-jun promoter furthermore showed that SCF was activating the c-jun promoter via the NF-jun transcription factor. Gel mobility shift assays showed that SCF increased the binding activity of NF-jun to its recognition site within 5 to 15 minutes. Binding activity peaked at 1 hour after exposure to SCF and declined to starting levels within 4 hours. The ability of SCF to enhance NF-jun binding activity was also dose-dependent in the range of 5 to 100 ng/mL. Exposure of GF-D8 and Mo7 cells to TGF-beta before the addition of SCF antagonized SCF-induced NF-jun binding. Moreover, whereas SCF was capable of functionally activating a heterologous promoter containing the NF-jun binding site, pretreatment of GF-D8 cells with TGF-beta abolished transcriptional activation of this heterologous promoter. These findings indicate that SCF-mediated activation of c-jun via NF-jun is crucial for the SCF-inducible proliferative response and is inhibited by TGF-beta. In additional experiments, the antisense technique was used. Treatment of GF-D8 and Mo7 cells with an antisense oligodeoxyribonucleotide directed against the translation initiation site of c-jun abolished the capacity of SCF to induce a proliferative response, whereas sense and nonsense oligomers had no effect. Taken together, our data indicate that the counteracting modulation of the binding activity of NF-jun by SCF and TGF-beta regulates the expression of the c-jun gene and thereby the proliferative state of the GF-D8 and Mo7 target.

High-energy resolution in X-ray scattering with the spectrometer INELAX. I. The principles and the test instrument

Very high-energy resolution measurements using X-rays can be achieved by extreme backreflection (Bragg angle close to 90°) from perfect crystals. This technique, combined with the high intensity of X-rays emitted by synchrotron-radiation sources, allowed the development of the instrument INELAX for inelastic scattering experiments. The principles and test results are discussed.

Low-frequency collective modes in dry and hydrated proteins

We have observed Brillouin-like low frequency collective modes in the scattering of 1 A neutrons from a fully in vivo deuterated protein. These modes are tentatively interpreted as due to short-lived coherent excitations propagating with velocities between 2,000 and 4,000 m/s in elements of the secondary structure and patches of closely associated water.