Effect of Flavobacterium psychrophilum on the neuroendocrine response of rainbow trout (Oncorhynchus mykiss) in a time course experiment.

The aim of this study was to examine the effects of Flavobacterium psychrophilum, a pathogen that is economically important in the aquaculture sector, on the neuroendocrine response of Oncorhynchus mykiss during a time course experiment with sampling at 0.5, 1, 2, 6, 10, and 30 days post injection (dpi). In the brain, serotonin (5HT) content increased in the infected group at all the measured time points, a similar pattern was observed for 5-hydroxyindole-3-acetic acid (5HIAA). Infected fish presented an increase in brain dopamine levels on day 0.5 and 1 dpi. A non-significant variation in noradrenaline levels was observed on all treatment days. Foregut 5-HT and 5-HIAA content in the infected group presented the highest 5-HT concentrations with 248.6 and 983.5 ng/g tissue at 0.5 dpi respectively. Midgut 5-HT and 5-HIAA levels presented the highest 5-HT concentrations, 486.9 ng/g tissue and 1006.4 ng/g tissue respectively, at the beginning of the experiment (0.5 dpi). 5-HT levels in the hindgut presented the highest concentrations with 233.9 ng/g tissue at 0.5 dpi, while 5-HIAA presented the highest concentrations, 690.5 ng/g tissue, at the same time point. After injection with F. psychrophilum the neuroendocrine response in rainbow trout was tissue dependent. Brain levels of 5HT and 5HIIA indicate that the neuroendocrine response increased together with dopamine following intramuscular infection. These increases are in line with reports from other authors, indicating an early response of catecholamines as neurotransmitters to stressful stimulus. In addition the intestinal response was also increased, implying that there could be a possible relationship between the serotonergic system at the intestinal level and the immune system.

The expression pattern of calcium signaling-related genes during smoltification of Salmo salar in productive conditions.

Variations in the mRNA expression of hepatic and muscle genes that are related to calcium signaling were analyzed by real-time qPCR in farmed Atlantic salmon (Salmo salar L. 1758) to determine changes in expression between parr and smolt stages. These organs were selected due to their close relationship with calcium signaling and metabolism (e.g., glycolysis, oxidative phosphorylation, muscle contraction). Differential expression between smolt and parr specimens and between organs was observed. Compared to parr specimens, smolts exhibited upregulated expression of the calcitonin receptor precursor, calcitonin receptor, calcitonin isoform, parathyroid hormone, and calmodulin in the liver. This pattern was inverse in muscle, with the exception of calmodulin, which was significantly upregulated in smolts compared to parr. Additionally, plasma calcium was decreased in the smolt condition. This study is the first to characterize the expression pattern of calcium signaling-related genes in the liver and muscle of parr and smolt S. salar. However, further functional studies are required to obtain a wider understanding about the physiological changes that accompany the productive conditions during smoltification.

Transcriptional activation of genes involved in oxidative stress in Salmo salar challenged with Piscirickettsia salmonis.

Piscirickettsiosis caused by Piscirickettsia salmonis constitutes one of the main problems in farmed salmonid and marine fishes. The objective of this study was to evaluate the modulation of genes involved in the oxidative stress in the liver and muscle of Salmo salar challenge with low dosage of P. salmonis. The treatment (in duplicate) were as follows: Control injection (culture medium) and P. salmonis injection (1 × 102 PFU/mL) with sampling (liver and muscle) at several time-points during the 42-days experimental period (dpi). In liver, the gene expression of superoxide dismutase (SOD) and acetylcholinesterase (AChE) had differences with the control group only at 7 dpi, compared with glutathione-S-transferase (GST) and heat shock protein 70 (HSP70) that presented increases at 7 and 21 dpi. The glutathione peroxidase (GPx) and catalase (CAT) mRNAs were elevated at 13 and 21 dpi, respectively. While glutathione reductase (GR) and cytochrome P450 (P450) did not show variations in their expression during the experimental course. In muscle, the expression of CAT and AChE was higher than in the control condition at 2 and 42 dpi, respectively. While the number of transcripts SOD, GPx, GR, GST, P450 and HSP70 showed increases at 7- and 42-days post injection. The results suggest a transcriptional activation of genes involved in oxidative stress in both liver and muscle, with expression profiles that were tissue-specific and dependent on the time. This is the first study that reveals the transcriptional participation of all these genes associated with oxidative stress in response to the injection of P. salmonis.

Ectoparasite Caligus rogercresseyi modifies the lactate response in Atlantic salmon (Salmo salar) and Coho salmon (Oncorhynchus kisutch).

Although Caligus rogercresseyi negatively impacts Chilean salmon farming, the metabolic effects of infection by this sea louse have never been completely characterized. Therefore, this study analyzed lactate responses in the plasma, as well as the liver/muscle lactate dehydrogenase (LDH) activity and gene expression, in Salmo salar and Oncorhynchus kisutch infested by C. rogercresseyi. The lactate responses of Atlantic and Coho salmon were modified by the ectoparasite. Both salmon species showed increasing in plasma levels, whereas enzymatic activity increased in the muscle but decreased in the liver. Gene expression was overexpressed in both Coho salmon tissues but only in the liver for Atlantic salmon. These results suggest that salmonids need more energy to adapt to infection, resulting in increased gene expression, plasma levels, and enzyme activity in the muscles. The responses differed between both salmon species and over the course of infection, suggesting potential species-specific responses to sea-lice infection.

Does the menopausal status of female gynecologists affect their prescription of menopausal hormone therapy?

OBJECTIVE: To evaluate whether menopausal status and symptoms among female gynecologists would influence their clinical behavior related to menopausal hormone therapy (MHT). METHODS: Female gynecologists of 11 Latin American countries were requested to fill out the Menopause Rating Scale and a questionnaire containing personal information and that related to MHT use. RESULTS: A total of 818 gynecologists accepted to participate (86.4%). Overall, the mean age was 45.0 ± 10.7 years, 32.2% were postmenopausal, and 17.6% worked in an academic position; 81.8% reported that they would use MHT if they have symptoms, regardless of menopausal status. Academic gynecologists favor personal MHT use at a higher rate (p = 0.04) and have a higher MHT prescription rate as compared to non-academic ones (p = 0.0001). The same trend was observed among post- as compared to premenopausal ones (p = 0.01) and among those who had hysterectomy alone as compared to those experiencing natural menopause (p = 0.002). The presence of menopausal symptoms did not influence their MHT prescription. Current use of MHT and alternative therapy was higher among post- than premenopausal gynecologists (both, p = 0.0001) and among those who had undergone hysterectomy than those experiencing natural menopause. A 38.5% perceived breast cancer as the main risk related to MHT, and a high proportion prescribed non-hormonal drugs (86.4%) or alternative therapies (84.5%). CONCLUSION: Most female gynecologists in this survey would use MHT if menopausal symptoms were present. Postmenopausal physicians use MHT and prescribe it to their symptomatic patients at a higher rate than premenopausal physicians.

External copper inhibits the activity of the large-conductance calcium- and voltage-sensitive potassium channel from skeletal muscle.

We have characterized the effect of external copper on the gating properties of the large-conductance calcium- and voltage-sensitive potassium channel from skeletal muscle, incorporated into artificial bilayers. The effect of Cu2+ was evaluated as changes in the gating kinetic properties of the channel after the addition of this ion. We found that, from concentrations of 20 microM and up, copper induced a concentration- and time-dependent decrease in channel open probability. The inhibition of channel activity by Cu2+ could not be reversed by washing or by addition of the copper chelator, bathocuproinedisulfonic acid. However, channel activity was appreciably restored by the sulfhydryl reducing agent dithiothreitol. The effect of copper was specific since other transition metal divalent cations such as Ni2+, Zn2+ or Cd2+ did not affect BK(Ca) channel activity in the same concentration range. These results suggest that external Cu2+-induced inhibition of channel activity was due to direct or indirect oxidation of key amino-acid sulfhydryl groups that might have a role in channel gating.

[Splenic abscess secondary to xanthogranulomatous pyelonephritis]. / Absceso esplénico secundario a pielonefritis xantogranulomatosa.

OBJECTIVE: We report another case of splenic abscess after nephrectomy, a condition which must be considered in the differential diagnosis of post-operative fever. METHODS/RESULTS: A 20-year-old man presented with lumbar pain and fever. A diagnosis of xanthogranulomatous pyelonephritis was made and he was treated by subcapsular nephrectomy. Thirty days later the patient presented with a lumbar fistula from a splenic abscess and was treated by splenectomy. CONCLUSIONS: Fistulas and abscesses are more common after nephrectomy for xanthogranulomatous pyelonephritis. In our view, the subcapsular approach is an additional risk factor for the foregoing complications.

Sequential versus alternating regimens in the treatment of advanced breast cancer. Argentine Breast Cancer Cooperative Group.

With the object of proving whether sequential or alternate forms of chemotherapy would be advantageous one over the other in treating advanced breast cancer and with the purpose of evaluating two different anthracyclines at equimolecular doses in the above-mentioned alternating regimens, 250 patients who had received no prior chemo- or hormonotherapy were entered in a prospective randomized trial. Group A was administered 4-epiadriamycin and cyclophosphamide for 8 courses, followed by 6 cycles of CMF, and medroxyprogesterone acetate (MPA) from the beginning of therapy until progression. In group B, adriamycin + cyclophosphamide were alternated with CMF every two courses until 14 cycles were completed. Group C received 4'-epiadriamycin + cyclophosphamide alternated with CMF for 14 courses. In groups B and C, MPA was administered as in group A. Two hundred and twenty-four patients were evaluated. CR + PR were observed in 55.8% of group A, 43.4% of group B, and 46.4% of group C. Median duration of responses was 16 months (m) in group A, 13 m in group B and 20 m in group C, and median survival (CR + PR) was 16.5 m in group A, 16 m in group B and 24 m in group C. There were no statistically significant differences among the three groups in terms of response rate, duration of response and survival; furthermore, toxicity was moderate in all groups. At equimolecular doses there were no differences between adriamycin and epirubicin in the alternating schedules.