Assessing the growth of Arctic charr (Salvelinus alpinus) (Linnaeus, 1758) in four salinities, under experimental conditions

Studies in Salvelinus alpinus, Arctic charr, indicate that it has a low capacity to hyposmorregulatory or adaption to sea in winter periods in Arctic waters. The investigation finds to determinate the rank optimum of salinity to can cultivate this species at Chile. The weight adequate was determined to join on the sea by analysis of gill Na+, K+-ATPase activity, that it was found between the ranks 80-130 g, with 14.5 U/mg. It underwent evaluation of fish growth of 72 g salinities from 0 (control), 18, 25 and 33 g/L (sea water) for 94 days. The results indicate that the largest increases were obtained in brackish water. T18 g/L and T25 g/L achieved growth of 25% and 19% on day 94 and term sampling respectively. It is important to mention that the 8% that survived in seawater introduced percentages growth 16.6% equivalent to brackish water and control. These results suggest that Salvelinus alpinus can grow in seawater, with levels of Na+, K+-ATPase similar to those submitted by Salmo salar with a weight not less than 80 g.

Spin-coated epoxy resin embedding technique enables facile SEM/FIB thickness determination of porous metal oxide ultra-thin films

A facile nonsubjective method was designed to measure porous nonconductive iron oxide film thickness using a combination of a focused ion beam (FIB) and scanning electron microscopy. Iron oxide films are inherently nonconductive and porous, therefore the objective of this investigation was to optimize a methodology that would increase the conductivity of the film to facilitate high resolution imaging with a scanning electron microscopy and to preserve the porous nature of the film that could potentially be damaged by the energy of the FIB. Sputter coating the sample with a thin layer of iridium before creating the cross section with the FIB decreased sample charging and drifting, but differentiating the iron layer from the iridium coating with backscattered electron imaging was not definitive, making accurate assumptions of the delineation between the two metals difficult. Moreover, the porous nature of the film was lost due to beam damage following the FIB process. A thin layer plastication technique was therefore used to embed the porous film in epoxy resin that would provide support for the film during the FIB process. However, the thickness of the resin created using conventional thin layer plastication processing varied across the sample, making the measuring process only possible in areas where the resin layer was at its thinnest. Such variation required navigating the area for ideal milling areas, which increased the subjectivity of the process. We present a method to create uniform thin resin layers, of controlled thickness, that are ideal for quantifying the thickness of porous nonconductive films with FIB/scanning electron microscopy.

Natal foraging philopatry in eastern Pacific hawksbill turtles

The complex processes involved with animal migration have long been a subject of biological interest, and broad-scale movement patterns of many marine turtle populations still remain unresolved. While it is widely accepted that once marine turtles reach sexual maturity they home to natal areas for nesting or reproduction, the role of philopatry to natal areas during other life stages has received less scrutiny, despite widespread evidence across the taxa. Here we report on genetic research that indicates that juvenile hawksbill turtles (Eretmochelys imbricata) in the eastern Pacific Ocean use foraging grounds in the region of their natal beaches, a pattern we term natal foraging philopatry. Our findings confirm that traditional views of natal homing solely for reproduction are incomplete and that many marine turtle species exhibit philopatry to natal areas to forage. Our results have important implications for life-history research and conservation of marine turtles and may extend to other wide-ranging marine vertebrates that demonstrate natal philopatry.

Immunostimulatory effect of salmon prolactin on expression of Toll-like receptors in Oncorhynchus mykiss infected with Piscirickettsia salmonis

In aquaculture, antibiotics are the traditional treatment used against bacterial infections. However, their use has increasingly come into question given their effects on fish and, possibly, on human health. Consequently, there is interest in developing alternative treatments aimed at stimulating the innate immune response of fish, which is the first line of defense against pathogens. In relation to this, the Toll-like receptors (TLR) aid in the selective identification of pathogens. The present study evaluated immunostimulatory activity of prolactin (PRL) hormone on expression levels of TLR1, 9, and 22, MyD88, and IL-1β during in vitro infection with the fish pathogen Piscirickettsia salmonis, in primary cultures of Oncorhynchus mykiss head kidney cells. Results indicated that PRL increased expression of TLRs and MyD88 during the first hours of bacterial infection, while a constant increase in expression was found for IL-1β. These findings suggest that PRL indirectly modulates expression of TLRs by activating expression of suppressors of cytokine signaling, thereby regulating immune response over long periods of time during bacterial infection.

A dinuclear Ru(ii) complex capable of photoinduced ligand exchange at both metal centers

{[Ru(CH₃CN)₃]₂(tppz)}⁴⁺ (tppz = tetra-2-pyridylpyrazine) undergoes photoinduced CH₃CN exchange with λ_irr ≥ 610 nm in H₂O from both metal centers.

Displasia renal multiquística segmentaria: hallazgos radiológicos y diagnóstico diferencial

Multicystic dysplasia of the kidney is the second most common cause of renal masses in newborns after hydronephrosis and the most frequent cause of cystic masses in childhood. We present the case of a cystic renal mass in an infant that was definitively diagnosed at histological examination to be segmental cystic dysplasia. Cystic renal dysplasia usually involves an entire kidney, and segmental multicystic renal dysplasia is rare. We review the etiology and pathogenesis of this entity, the radiological findings, and the main differential diagnoses with the aim of establishing the correct diagnosis and differentiating this entity from other focal cystic kidney lesions affecting children.

The burden of acute postoperative pain and the potential role of the COX-2-specific inhibitors

Pain has been recognized as a problem of global proportions, and postoperative pain is one of the most common types of pain. Postoperative pain is acute and, although it is preventable and/or treatable, it is often undertreated. Lack of appropriate analgesic management has significant impact on clinical and economic outcomes. Negative clinical outcomes of inadequately managed acute postoperative pain include extended hospitalization, compromised prognosis, higher morbidity and mortality, and the development of a chronic pain state as a result of neuronal plasticity. Although estimating the economic burden of postoperative pain is difficult, this burden is considerable and results from direct costs due to excess health-care resource use, as well as indirect costs due to reduced patient functionality and productivity. These latter factors also have a significant adverse impact on patients' quality of life and may be associated with the development of depression and anxiety. Thus, improved clinical outcomes are dependent not only on the availability of effective drugs but also on their appropriate utilization. A multimodal approach incorporating different drugs and techniques is effective in reducing postoperative pain but is limited by the currently available therapies. The efficacy of opioids is well established, but there are concerns about dependency, respiratory depression and side-effects, which patients often find intolerable. Non-steroidal anti-inflammatory drugs (NSAIDs) are effective as adjunctive medication in a multimodal regimen but are associated with side-effects, such as platelet dysfunction and renal and gastrointestinal toxicity, that have special clinical significance in patients undergoing surgical procedures. Cyclooxygenase-2-specific inhibitors such as celecoxib, rofecoxib and valdecoxib, were developed to provide the efficacy of non-specific NSAIDs while limiting associated toxicity. These agents have demonstrated analgesic efficacy and an opioid-sparing effect in a variety of surgical procedures, suggesting their value as an alternative to non-specific NSAIDs. Further studies are needed to determine the impact of these drugs on clinical and economic outcomes when used in a programme of postsurgical pain management.

Economic evaluation of oral valdecoxib versus diclofenac in the treatment of patients with rheumatoid arthritis in a randomized clinical trial

In contrast to economic models that provide probabilistic estimates of economic impact, data extracted from clinical trials may be used to evaluate and compare actual resource utilization and costs. Health-care resource utilization and the costs of these resources were compared from the perspective of the UK National Health Service using data obtained in a 6-month clinical trial of oral valdecoxib 20 mg once daily and diclofenac 75 mg twice daily for the symptomatic treatment of rheumatoid arthritis. However, calculated health-care costs were exclusive of drug acquisition costs because the price of valdecoxib was not available at the time of analysis. While the efficacy of the two treatments was similar, use of valdecoxib was associated with a reduction in total health-care costs amounting to approximately 200 British pounds per patient. This lower cost was associated with reduced use of health-care resources for gastrointestinal serious adverse events (gastrointestinal SAEs). In particular, the incidence of hospitalization and number of hospital days for gastrointestinal SAEs was lower in the valdecoxib group. Analysis of cost per gastrointestinal SAE favoured valdecoxib (cost savings of 742 British pounds), suggesting that even when these events did occur they were less severe. When costs of gastrointestinal SAEs were averaged over the entire population, valdecoxib was suggested to have lower total costs per patient compared with diclofenac (cost savings of 115 British pounds per patient), mainly resulting from significant savings in hospitalization costs (76.49 British pounds per patient). These data are consistent with economic models and suggest that the favourable gastrointestinal profile of valdecoxib observed in clinical trials will be of economic benefit.

Transverse instabilities in chemical Turing patterns of stripes

We present a theoretical and experimental study of the sideband instabilities in Turing patterns of stripes. We compare numerical computations of the Brusselator model with experiments in a chlorine dioxide-iodine-malonic acid (CDIMA) reaction in a thin gel layer reactor in contact with a continuously refreshed reservoir of reagents. Spontaneously evolving Turing structures in both systems typically exhibit many defects that break the symmetry of the pattern. Therefore, the study of sideband instabilities requires a method of forcing perfect, spatially periodic Turing patterns with the desired wave number. This is easily achieved in numerical simulations. In experiments, the photosensitivity of the CDIMA reaction permits control and modulation of Turing structures by periodic spatial illumination with a wave number outside the stability region. When a too big wave number is imposed on the pattern, the Eckhaus instability may arise, while for too small wave numbers an instability sets in forming zigzags. By means of the amplitude equation formalism we show that, close to the hexagon-stripe transitions, these sideband instabilities may be preceded by an amplitude instability that grows transient spots locally before reconnecting with stripes. This prediction is tested in both the reaction-diffusion model and the experiment.

Stability of Turing patterns in the Brusselator model

The selection and competition of Turing patterns in the Brusselator model are reviewed. The stability of stripes and hexagons towards spatial perturbations is studied using the amplitude equation formalism. For hexagonal patterns these equations include both linear and nonpotential spatial terms enabling distorted solutions. The latter modify substantially the stability diagrams and select patterns with wave numbers quite different from the critical value. The analytical results from the amplitude formalism agree with direct simulations of the model. Moreover, we show that slightly squeezed hexagons are locally stable in a full range of distortion angles. The stability regions resulting from the phase equation are similar to those obtained numerically by other authors and to those observed in experiments.

Quality of life in patients with spinal cord injury receiving Viagra (sildenafil citrate) for the treatment of erectile dysfunction

STUDY DESIGN

A multicenter, randomized, double-blind, placebo-controlled, flexible-dose, two-way crossover study conducted June 1996 through January 1997.

OBJECTIVES

To evaluate the effect of sildenafil citrate (VIAGRA(R)) on the quality of life (QoL) of men with erectile dysfunction (ED) caused by spinal cord injury (SCI).

SETTING

Study centers in Australia, Belgium, France, Germany, Norway, Sweden and the United Kingdom.

METHODS

Questions 13 and 14 of the 15-item International Index of Erectile Function (IIEF) addressed QoL issues directly related to ED in 178 men with SCI. A 5-item questionnaire addressing concerns that men had about their erection problems was also used to evaluate the impact of ED on QoL. Several commonly used psychometric instruments, including the Medical Outcomes Survey (MOS) Short Form-12, Psychological General Well-Being Index, and MOS Family Survey, assessed general QoL issues.

RESULTS

Significant improvements were seen for overall satisfaction with sex life (IIEF Q13), sexual relationship with partner (IIEF Q14), and concerns about erectile problems (P<0.0001). Improvements were reported in scores for the generic QoL parameters of mental health, well-being, depression, and anxiety (P<0.05 sildenafil versus placebo).

CONCLUSION

Treatment with sildenafil can significantly improve key QoL parameters in men with ED caused by SCI.

SPONSORSHIP

This study was funded by Pfizer Inc. Spinal Cord (2000) 38, 363 - 370.

Heparin plus aspirin as a "single" therapy for recurrent spontaneous abortion associated with both allo- and autoimmunity

PROBLEM

The aim of this study was to contribute to the study of the pathogenesis and the treatment of recurrent spontaneous abortion (RSA) associated with immune alterations.

METHOD OF STUDY

This is a prospective clinical trial with 11 patients with RSA associated with allo- and autoimmunity not receiving lymphocyte immunizations but only heparin and aspirin preconceptionally and through pregnancy. A concurrent group of 8 patients receiving a complete therapy (lymphocyte immunizations, heparin, and aspirin) but not receiving heparin and aspirin preconceptionally is also included in this report.

RESULTS

The rate of pregnancy success in these patients was 90.9% (10/11), and the rate of success of the concurrent group was 75.0% (6/8).

CONCLUSIONS

The results are in agreement with the working hypothesis regarding the possible final common mechanism in the pathogenesis of abortion associated with allo- and autoimmunity. The "single" therapy with heparin and aspirin was effective, less costly, and logistically simpler to provide than a complete therapy including lymphocyte immunizations.

Cell microchimerism in patients with recurrent spontaneous abortion: preliminary results

The goal of this study was to determine the prevalence of non-host male cell microchimerism in a group of women with a history of recurrent spontaneous abortion (RSA). The detection of male cell microchimerism was based upon amplification of a fragment of Y chromosome DNA obtained from peripheral blood mononuclear cells from the mother. The amplification products were electrophoresed, transferred onto nylon membranes and hybridized with a specific 32P-labelled probe. The products were visualized by autoradiography. Seventy-seven patients with RSA were studied. Some patients (42.8%) had received immunotherapy for RSA using live mononuclear cells from male donors. Of the 77 patients 46 (59.7%) were positive for the selected Y chromosome sequence, 22 (28.6%) had no evidence of Y chromosome DNA and in nine (11.7%) cases the chimeric status could not be defined since the amplified band was too faint to be clearly assigned as positive. Twenty patients were pregnant at the time of sampling. There were no statistically significant differences among the different variables studied: age of the mother, number of previous pregnancies, number of previous immunotherapeutic inoculations or period of time between the last inoculation and sampling. Male cell microchimerism has been reported in some but not all women who have given birth to male children. The dynamics for the establishment of this chimeric status and its persistence have not been defined. We found that most patients with RSA (59.7%) were positive for microchimerism but that this could not be correlated with abortion, current pregnancy or leukocyte immunotherapy. A prospective study is being undertaken to determine if there is a subset of patients negative for chimerism who become positive after alloimmunotherapy with male lymphocytes and have an improved prognosis for successful pregnancy.

Serologic response to measles-mumps-rubella vaccine among children with upper respiratory tract infection

The influence of concurrent upper respiratory tract infection (URTI) on immune response to MMR (measles, mumps, rubella) vaccine was evaluated by measuring IgG levels for each viral component immediately before vaccination and 6 months after vaccination in 198 12-month-old children (101 children without URTI and 97 with URTI at time of vaccination). None of the children had antibodies to measles, mumps or rubella before vaccination. Seroconversion rates and the geometric means of the antibody titers in children without URTI and in children with URTI at the time of vaccination were similar. MMR vaccination should not be delayed in children with such infections.

Ischemic stroke due to fibromuscular dysplasia

Fibromuscular dysplasia is a segmental, nonatheromatous angiopathy. A 13-year-old patient is reported with stroke. Left-sided carotid angiogram revealed typical findings of fibromuscular dysplasia in the left carotid artery.