Cost-effectiveness of bulk-tank milk testing for surveys to demonstrate freedom from infectious bovine rhinotracheitis and bovine enzootic leucosis in Switzerland.

In Switzerland, annual surveys to substantiate freedom from infectious bovine rhinotracheitis (IBR) and enzootic bovine leucosis (EBL) are implemented by a random allocation of farms to the respective survey as well as blood sampling of individual animals at farm level. Contrary to many other European countries, bulk-tank milk (BTM) samples have not been used for active cattle disease surveillance for several years in Switzerland. The aim of this project was to provide a financial comparison between the current surveillance programme consisting of blood sampling only and a modified surveillance programme including BTM sampling. A financial spreadsheet model was used for cost comparison. Various surveillance scenarios were tested with different sample sizes and sampling frequencies for BTM samples. The costs could be halved without compromising the power to substantiate the freedom from IBR and EBL through the surveillance programme. Alternatively, the sensitivity could be markedly increased when keeping the costs at the actual level and doubling the sample size. The risk-based sample size of the actual programme results in a confidence of 94,18 % that the farm level prevalence is below 0,2 %. Which the doubled sample size, the confidence is 99,69 % respectively.

The expression and impact of antifungal grooming in ants.

Parasites can cause extensive damage to animal societies in which many related individuals frequently interact. In response, social animals have evolved diverse individual and collective defences. Here, we measured the expression and efficiency of self-grooming and allo-grooming when workers of the ant Formica selysi were contaminated with spores of the fungal entomopathogen Metarhizium anisopliae. The amount of self-grooming increased in the presence of fungal spores, which shows that the ants are able to detect the risk of infection. In contrast, the amount of allo-grooming did not depend on fungal contamination. Workers groomed all nestmate workers that were re-introduced into their groups. The amount of allo-grooming towards noncontaminated individuals was higher when the group had been previously exposed to the pathogen. Allo-grooming decreased the number of fungal spores on the surface of contaminated workers, but did not prevent infection in the conditions tested (high dose of spores and late allo-grooming). The rate of disease transmission to groomers and other nestmates was extremely low. The systematic allo-grooming of all individuals returning to the colony, be they contaminated or not, is probably a simple but robust prophylactic defence preventing the spread of fungal diseases in insect societies.

Gas phase analogs of stable sodium-tin Zintl ions: anion photoelectron spectroscopy and electronic structure.

Mass spectrometry and photoelectron spectroscopy together with first principles theoretical calculations have been used to study the electronic and geometric properties of the following sodium-tin, cluster anion/neutral cluster combinations, (Na(n)Sn(4))(-)/(Na(n)Sn(4)), n = 0-4 and (NaSn(m))(-)/(NaSn(m)), m = 4-7. These synergistic studies found that specific Zintl anions, which are known to occur in condensed Zintl phases, also exist as stable moieties within free clusters. In particular, the cluster anion, (Na(3)Sn(4))(-) is very stable and is characterized as (Na(+))(3)(Sn(4))(-4); its moiety, (Sn(4))(-4) is a classic example of a Zintl anion. In addition, the cluster anion, (NaSn(5))(-) was the most abundant species to be observed in our mass spectrum, and it is characterized as Na(+)(Sn(5))(2-). Its moiety, (Sn(5))(2-) is also known to be present as a Zintl anion in condensed phases.

[Airway management in sedated patients]. / Atemwegsmanagement beim sedierten Patienten.

The decrease in airway muscular tone seen during natural sleep and sedation, as well as in the supine position, can lead to anatomic changes in the structures that surround the airway. Some patients need sedation for diagnostic or interventional procedures. In these patients, knowledge about morphological and mechanical aspects of the soft-tissue structures is essential for a complete understanding of the changes that occur in upper airway caliper. Maintaining the patency of the upper airway during spontaneous breathing in sedated or anesthetized patients may become a major challenge for anesthetists, especially in patients with preexisting sleep disordered breathing or airway obstruction. In addition to different techniques of body positioning, simple airway maneuvers, such as chin lifting can maintain airway patency or open an obstructed upper airway. These maneuvers need an age-related evaluation and application.

[Laryngeal alterations following endotracheal intubation and use of larynx masks]. / Laryngeale Veränderungen nach endotrachealer Intubation und Anwendung der Larynxmaske.

After endotracheal intubation patients most frequently report pharyngolaryngeal complaints. Subsequent impairment of vocal performance might lead to general impairment of communication and job-related performance. Most prevalently, swollen mucosa, hematomas, granuloma and edema in the larynx can be observed after intubation. Limitations of respiratory vocal fold mobility appear less frequently. Knowledge of the pathophysiological aspects and causative factors associated with laryngopharyngeal morbidity are essential cornerstones of quality assurance in perioperative respiratory tract management. This review describes the effects of endotracheal intubation and application of larynx masks in relation to laryngeal morbidity.

Grain formation modulated by molecular hydrogen evaporation in the interstellar medium.

A mechanism for grain growth and formation in the interstellar medium is proposed. In this mechanism, hydrogen molecules act as moderators. The process begins when they physisorb to the surface of the grain. Then, when a collision with a heavy atom occurs, the bonding energy is carried away by the evaporation of hydrogen molecules. Estimates are made of the number of hydrogen molecules bound to the surface of a grain that would be sufficient to facilitate this mechanism at 13 K for amorphous carbon and 8 K for a silicate grain.

Transfer of maternal colostral leukocytes promotes development of the neonatal immune system Part II. Effects on neonatal lymphocytes.

It has been established that maternal leukocytes, conditioned by the mammary environment, cross the neonatal gut and circulate in the newborn calf. However, the impact of these cells on the development of neonatal immunity remains to be determined. This study examined the effects of maternal colostral leukocytes on development and maturation of neonatal adaptive immunity by examining the expression of surface markers on neonatal lymphocytes. At birth, neonatal calves were fed whole colostrum, or colostrum that had the maternal cells removed (cell-free colostrum), from their respective dams. Peripheral blood samples were collected at regular intervals over the first 4 weeks of life and lymphocytes were evaluated for surface expression of cellular markers. The results of these studies demonstrated that calves receiving whole colostrum had fewer CD11a positive lymphocytes in circulation during the first 2 weeks of life and this marker was expressed at a lower density than calves receiving cell-free colostrum. In addition, calves receiving whole colostrum also had a higher percentage of lymphocytes expressing the activation markers CD25 and CD26 by 7 days after birth. During the first week of life, lymphocytes from calves receiving whole colostrum had a higher density of MHC class I expression on their surfaces than cells from calves receiving cell-free colostrum. In general, these results indicate that transfer of maternal cells with colostrum allows for more rapid development of lymphocytes and maternal cells appeared to enhance their activation.

Transfer of maternal colostral leukocytes promotes development of the neonatal immune system I. Effects on monocyte lineage cells.

Although it has been established that maternal leukocytes traffic from colostrum into the neonatal circulation, the effects of these cells on neonatal immunity are only beginning to be understood. This study examined the effects of maternal colostral leukocytes on development and maturation of neonatal antigen presenting cells. At birth, groups of neonatal calves received whole or cell-free colostrum (CFC) from their respective dams. Peripheral blood samples were obtained over the first 4 weeks of life, and expression of surface markers associated with cellular activation and physiological stress were monitored on monocyte lineage cells. Calves receiving cell-free colostrum at birth expressed elevated levels of CD11a, CD11c, and CD14, compared to calves receiving whole colostrum (C). Calves receiving cell-free colostrum had an elevated number of monocytes in the peripheral blood during the first 2 weeks of life, however, these cells expressed lower levels of expression of CD25 and MHC class I compared to calves receiving whole colostrum. The most significant differences in marker expression occurred within the first 7 days of life.

Spleen but not tumor infiltration by dendritic and T cells is increased by intravenous adenovirus-Flt3 ligand injection.

Dendritic cell (DC) expansion is regulated by the hematopoietic growth factor fms-like tyrosine kinase 3 ligand (Flt3L). DCs are critical to the control of tumor growth and metastasis, and there is a positive correlation between intratumoral DC infiltration and clinical outcome. In this report, we first demonstrate that single intravenous (i.v.) injections of adenovirus (Adv)-Flt3L significantly increased splenic dendritic, B, T and natural killer (NK) cell numbers in both normal and mammary tumor-bearing mice. In contrast, the numbers of DCs and T cells infiltrating the tumors were not increased. Consistent with the minimal effect on immune cell infiltration, i.v. Adv-Flt3L injections had no therapeutic activity against orthotopic mammary tumors. In addition, we noted tumor and Adv-Flt3L expansion of Gr1(+)CD11b(+) immature myeloid suppressor cells (IMSCs), which may inhibit the therapeutic efficacy of Adv-Flt3L-expanded DCs.

Rapid infusion of a phospholipid emulsion attenuates the effects of endotoxaemia in horses.

REASONS FOR PERFORMING STUDY: Endotoxaemia currently is associated with a poor prognosis in horses. The results of recent trials in other species indicate that phospholipid emulsions reduce the deleterious effects of endotoxin (LPS). However, in a previous study in horses, a 2 h infusion of emulsion caused an unacceptable degree of haemolysis. HYPOTHESIS: Rapid administration of a lower total dose of emulsion would reduce the effects of LPS and induce less haemolysis; the emulsion would reduce inflammatory effects of LPS in vitro. METHODS: Twelve healthy horses received an i.v. infusion either of saline or a phospholipid emulsion (100 mg/kg), followed immediately by E. coli 055:B5 LPS (30 ng/kg). Clinical parameters, haematological profiles, serum tumour necrosis factor (TNF) activity, serum lipid profiles, urine analyses and severity of haemolysis were monitored before and at selected times after LPS. Monocytes were also incubated in vitro with LPS in the presence or absence of emulsion, after which TNF and tissue factor activities were determined. RESULTS: Clinical signs of endotoxaemia were reduced in horses receiving the emulsion, including clinical score, heart rate, rectal temperature, serum TNF activity, and the characteristic leucopenic response to LPS, when compared to horses not receiving the emulsion. Three horses receiving the emulsion had none, 2 had mild and one had moderate haemolysis. There were no differences in urinalysis results and creatinine concentrations, either within the groups over time or between the groups. Serum concentrations of phosphatidylcholine, bile acids and triglycerides peaked immediately after the infusion; there were no significant changes in concentrations of nonesterified fatty acids or cholesterol. Incubation of equine monocytes with emulsion prevented LPS-induced TNF and tissue factor activities. CONCLUSIONS: Rapid administration of emulsion significantly reduced inflammatory effects of LPS in vivo and caused a clinically insignificant degree of haemolysis. The results of the in vitro studies indicate that emulsion prevents not only LPS-induced synthesis of cytokines, but also expression of membrane-associated mediators (i.e. tissue factor). POTENTIAL RELEVANCE: Rapid i.v. administration of emulsions containing phospholipids that bind endotoxin may provide a clinically useful method of treating endotoxaemia in horses.

Evaluation of multiple immune parameters after vaccination with modified live or killed bovine viral diarrhea virus vaccines.

The development of immunity to vaccine antigen was examined using three prime/boost strategies and the progression of immune activities was evaluated over the course of 8 weeks. Calves were vaccinated and multiple immune parameters were evaluated using several methods to assess humoral or cellular immunity from the same samples in parallel. The three vaccination protocols used were a killed vaccine followed by a killed boost (killed/killed), MLV vaccine and boost (MLV/MLV), or a MLV vaccine and killed boost (MLV/killed). All the vaccines used included modified live IBR/PI3 viruses to make the bystander context as similar as possible. The Singer strain of BVDV was used as the source antigen in the killed vaccine, and the NADL strain of BVDV was used in the MLV vaccine. Controls received a vaccine containing only MLV IBR/PI3. The assessment panel measured SN titers, as well as lymphocyte proliferation, cytokine mRNA expression, intracellular cytokine production, and released IFN-gamma after in vitro stimulation with three strains of BVDV virus. MLV/MLV and MLV/killed groups developed significant SN titers to the type 1 BVDV virus strains, Singer and NADL, and low crossover titers were also seen to the type 2 strain, 890 over the evaluation period. These two groups showed significant proliferation in response to the NADL virus as compared to controls. Multiple immune assessments were conducted simultaneously to attempt to provide a broader, more in depth evaluation of immune response to these BVDV vaccination protocols. We observed that the correlation among most of the assays conducted were weak; the correlation between SN titers and cellular proliferation assays demonstrated a moderate correlation.

Colostrum induced phenotypic and trafficking changes in maternal mononuclear cells in a peripheral blood leukocyte model for study of leukocyte transfer to the neonatal calf.

The relationship between the colostral environment and the function of leukocytes in colostrum is not clearly defined. This study examined the effects of defatted, acellular colostrum (AC) on the phenotype of peripheral blood mononuclear cells (PBMC) and their capacity to enter the circulation of neonatal calves after ingestion as a model of this relationship. Maternal PBMC were exposed to medium alone or medium supplemented with 25% AC. Expression of CD11a, CD11b, CD11c, CD43, CD49d, CD49e, and CD62L was assessed on freshly isolated and treated PBMC. Exposure to AC increased the percentage of cells expressing CD11a, CD11c and CD43, but decreased the percentage of cells expressing CD62L relative to freshly isolated PBMC. The density of expression of CD11b and CD11c was reduced, but increased for CD43 after exposure to AC relative to freshly isolated PBMC. Density of CD62L expression and percentage of cells expressing CD11a and CD43 were significantly different for cells treated with AC relative to medium alone. Further, these changes could not be attributed to occult bacterial contamination of the AC, as treatment of PBMC with LPS in the same medium yielded none of the observed changes. Maternal PBMC (treated as described) were labeled with the fluorescent tracer, PKH26-GL, and fed to neonatal calves within 6 h of birth. The circulation of these cells in the neonate was monitored by flow cytometry. We observed that: (1) cells exposed to AC, but not medium alone, entered the circulation; (2) peak trafficking occurred 12-24 h after ingestion; (3) a large fraction of labeled cells appeared in the neonatal circulation; and (4) labeled cells disappeared from circulation by 36 h after ingestion. This study indicates that exposure to the colostral environment induced phenotypic changes facilitating trafficking of colostral cells into the neonate.

A fundamental analysis of enhanced cross-coupling catalytic activity for palladium clusters on graphene supports.

Combining the recyclability of heterogeneous catalysts with the high activity of ligated homogeneous catalysts for the production of complex organic molecules is a cardinal goal of catalyst development. We have investigated the activity of ultra-fine Pd clusters bound to vacancy defective sites in graphene and found that the defective graphene both serves as a support to stabilize the recyclable catalyst, and also functions as a ligand enhancing the catalytic activity. In this paper, we report computational and experimental results that provide insights into the nature of the interfacial interactions between metal nanoparticles and defect sites on the graphene surface. Theoretical investigations reveal that while the vacancy/void sites on the graphene surface strongly bind to the metal clusters providing enhanced stability against leaching, graphene also serves as a reservoir of electron density that effectively reduces the activation energy of specific steps within the catalytic cycle. Furthermore, multiple experimental methods were used to unambiguously demonstrate that these cross-coupling reactions are occurring at the Pd/G catalyst surface.

Horizontal optokinetic nystagmus in unilaterally enucleated pigmented rats: role of the pretectal commissural fibers.

Monocular enucleation reduces the asymmetry of horizontal optokinetic nystagmus (H-OKN) in afoveate mammals by increasing responses to naso-temporal visual stimulation. The origin of these larger responses was investigated in adult pigmented rats monocularly enucleated as neonates or as adults by analyzing retinal and commissural projections to the deafferented nucleus of the optic tract (NOT) and the functional role of this nucleus before and after section of the posterior commissure. Anatomically, monocular enucleation reduces the volume of the contralateral deafferented NOT. Anterograde tracers injected in the intact eye reveal a crossed projection of the retina to the NOT and to the dorsal (DTN) and medial (MTN) terminal nuclei of the accessory optic system as in normal rats. In addition, there is an uncrossed projection to the MTN in the rats enucleated as neonates. Retrograde tracer injected in the deafferented NOT confirms the absence of an uncrossed retinal projection but reveals connections between both NOT via the posterior commissure as in normal rats. Electrophysiologically, the larger naso-temporal optokinetic responses in monocularly enucleated rats return to normal after posterior commissurotomy. This study demonstrates that no anatomical remodelling takes place to increase naso-temporal responses in monocularly enucleated rats. The larger responses must then result from functional changes. The role of exclusive contralateral projections of the retina to the NOT and of the commissural connections in mediating the asymmetry of the optokinetic nystagmus in afoveate mammals is discussed.

Horizontal optokinetic ocular nystagmus in the pigmented rat.

Horizontal optokinetic nystagmus was elicited in rats by rotation of a pattern of bright dots projected onto a cylinder surrounding the animal. Eye position was measured with the electromagnetic search coil technique. Optokinetic stimuli consisted either of velocity steps of pattern rotation or sinusoidal oscillations. Closed-loop gain (slow phase eye velocity/pattern velocity) of steady-stage step responses in binocular vision ranged between 0.8 and 1.0 for pattern velocities up to 20-40 degrees/s and decreased thereafter. Open-loop gain (steady-state slow phase velocity/retinal slip velocity) was dependent on retinal slip velocity and decreased linearly in double logarithmic plot from about 30 (at 0.5 degree/s) to about 9 (at 5 degrees/s). For retinal slip velocities larger than 5 degrees/s open-loop gain decayed faster and reached about 1 at 30 degrees/s. Step response profiles showed a gradual increase in slow phase eye velocity reaching steady-state after a time period roughly proportional to stimulus velocity. Initial slow phase velocity measured within 500 ms after stimulus onset reached between 2 and 4 degrees/s and was largely independent of stimulus amplitudes above 10 degrees/s. Occasionally rats showed fast rises in slow phase eye velocity at the onset of the step response profiles. Primary and secondary optokinetic afternystagmus were present. Duration of primary afternystagmus was largely independent of stimulus amplitude and lasted 8.0 +/- 4 s. Closed-loop gain of steady-state step responses in monocular vision was, for temporonasal stimuli, similar to that measured in binocular condition while for nasotemporal stimulation gain was much smaller even at low stimulus velocities. Sinusoidal modulation of slow phase velocity was linearly dependent on stimulus velocity; the linear range decreased as frequency of stimulation increased. Slow phase velocity gain was relatively constant (ca 0.8) between 0.05 and 0.3 Hz and showed only a small tendency to decrease at larger stimulus frequencies. Phase-lag increased strongly with stimulus frequency and could be fitted by assuming a response time delay of 100 ms. The results show that the rat's optokinetic system is qualitatively similar to that found in another lateral-eyed species, namely the rabbit. At a quantitative level, however, both fast and slow optokinetic response dynamics appear to be better developed in the rat than in the rabbit.(ABSTRACT TRUNCATED AT 400 WORDS)

More thoughts on the unconscious: reply to Brody and to Lewicki and Hill.

Brody (1989) and Lewicki and Hill (1989) present commentaries on my central thesis (Reber, 1989) that there exist powerful induction routines that operate largely independently of awareness and yield rich and complex tacit knowledge that resists attempts to make it conscious, although these commentaries are of dramatically different kinds. Because there is a fairly clear basis of agreement between Lewicki and Hill and the points that I made, this reply deals almost entirely with the issues raised by Brody. The focus is on two classes of issues: (a) those of a methodological nature that surround the general problem of doing experiments on unconscious cognition and (b) those that derive from considerations of evolutionary biology that provide a basis for arguing that implicit operations are primary and form the foundation for conscious processes.

Flt3 ligand bioactivity and pharmacology in neoplasia.

Fms-like tyrosine kinase 3 ligand (Flt3L) has multiple effects on the hematopoietic and immune systems. Further, preclinical studies have suggested potential therapeutic activity against cancer. Flt3L is a potent hematopoietic cytokine, capable of stimulating the expansion and differentiation of hematopoietic progenitor and stem cells. Administration of Flt3L mobilizes hematopoietic cells from the bone marrow (BM) into the blood, lymphoid organs, and parenchymal tissues. This mobilization activity, especially effective in combination with granulocyte colony stimulating factor (G-CSF), has stimulated studies of Flt3L in hematopoietic stem cell (HSC) transplantation. In addition to its effects on hematopoietic stem and progenitor cells, Flt3L has been shown to increase the frequency and number of dendritic cells (DCs) within the circulatory system and solid organs. DC expansion by Flt3L has been the focus of preclinical and clinical studies on antigen (Ag) specific T-cell mediated immunity. The mechanism for the augmentation of T-cell mediated immunity has yet to be completely identified, although Flt3L's ability to expand DCs in lymphoid and non-lymphoid tissues is involved. This expansion occurs primarily with DCs, which secrete interleukin (IL) 12. Consistent with the expansion of this DC population, treatment with Flt3L enhances T-cell mitogenesis and preferentially induces type 1 T-cell responses. However, the DCs resulting from Flt3L administration are immature, leading in some studies to the induction of tolerance. This review focuses on the effects of Flt3L on DCs and other effector populations, and on its potential activity as a therapeutic agent for cancer, alone and in combination with vaccines.

Acute effects of continuous rotational therapy on ventilation-perfusion inequality in lung injury.

OBJECTIVE: To investigate ventilation-perfusion (VA/Q) relationships, during continuous axial rotation and in the supine position, in patients with acute lung injury (ALI) using the multiple inert gas elimination technique. DESIGN: Prospective investigation. SETTING: Eighteen-bed intensive care unit in a university hospital. PATIENTS AND INTERVENTIONS: Ten patients with ALI (PaO2/FIO2 ratio < 300 mm Hg) were mechanically ventilated in a pressure controlled mode and placed on a kinetic treatment table. MEASUREMENTS AND RESULTS: Distributions of VA/Q were determined 1) during rotation (after a period of 20 min) and 2) after a resting period of 20 min in the supine position. During axial rotation, intrapulmonary shunt (19.1 +/- 15% of cardiac output) was significantly reduced in comparison with when in the supine position (23 +/- 14%, p < 0.05), areas with "low" VA/Q were not affected by the positioning maneuver. General VA/Q mismatch (logarithmic distribution of pulmonary blood flow) was decreased during rotation (0.87 +/- 0.37) in comparison with when the patient was in the supine position (0.93 +/- 0.37, p < 0.05). Arterial oxygenation was significantly improved during continuous rotation (PaO2/FIO2 = 217 +/- 137 mm Hg) as compared with in the supine position (PaO2/FIO2 = 174 +/- 82 mm Hg, p < 0.05). The positive response of the continuous rotation on arterial oxygenation was only demonstrated in patients with a Murray Score of 2.5 or less, indicating a "mild to moderate" lung injury, while in patients presenting with progressive ARDS (Murray Score > 2.5), the acute positive response was limited. CONCLUSIONS: Continuous axial rotation might be a method for an acute reduction of VA/Q mismatch in patients with mild to moderate ALI, but this technique is not effective in late or progressive ARDS. Further studies including a large data collection are needed.

Hyper- and hypogravity alter posture in rats compensated on Earth for a vestibular asymmetry.

Head posture and neck muscle activity (EMGs) were examined in unilateral (UL) and bilateral (BL) vestibularly lesioned rats in hypergravity (1.7 g) and hypogravity (0 g) during parabolic flights. Compared with BL rats taken as control, the head and the body of UL deviated toward the lesion side at 0 g and toward the intact side at 1.7 g. Recorded in head fixed condition, left and right EMGs remained symmetrical in BL while UL rats displayed an asymmetry between left and right muscles at 1.7 g, but not at 0 g. These results demonstrate that an experimental otolithic asymmetry, compensated on Earth, can become unbalanced in altered gravity. Paradoxically, the utricular system appears to play a major role in that process.

Optokinetic and vestibulo-ocular reflex adjustment by GABA antagonists.

We determined if high and low doses of anti-GABAergic drugs have opposite effects on the visuo-vestibular activity in pigmented rats and examined a possible correlation with the level of GABA in the related structures. First, the horizontal optokinetic and vestibulo-ocular reflexes of most animals were depressed by high doses of anti-GABAergic drugs (10(-3) M purified picrotoxin or 10(-6) M picrotoxin in unpurified vegetal extract). Simultaneously, a drop in GABA level in the cerebellum and posterior brainstem was detected. Second, after a subsequent injection (1 ml) of the diluted extract (10(-13) M picrotoxin), the reflexes returned to normal despite the fact that no correlation with the GABA level was found. These results demonstrate that small doses of anti-GABAergic drugs reverse the depressive effect created by large doses of these drugs on the oculomotor system, and even adjust the reflexes to the stimulation. This adjustment, without correlation with the GABA level, suggest a powerful effect of very low dose of the drug to modulate either the activity of the cerebellar inhibiting input or of the vestibular nuclei neurons or to trigger the adaptation by other neurotransmitter systems involved in the performances of the reflexes.