Long-term regulation of Na+,K+-ATPase in opossum kidney cells by ouabain

Na(+),K(+)-ATPase, a basolateral transporter responsible for tubular reabsorption of Na(+) and for providing the driving force for vectorial transport of various solutes and ions, can also act as a signal transducer in response to the interaction with steroid hormones. At nanomolar concentrations ouabain binding to Na(+),K(+)-ATPase activates a signaling cascade that ultimately regulates several membrane transporters including Na(+),K(+)-ATPase. The present study evaluated the long-term effect of ouabain on Na(+),K(+)-ATPase activity (Na(+) transepithelial flux) and expression in opossum kidney (OK) cells with low (40) and high (80) number of passages in culture, which are known to overexpress Na(+),K(+)-ATPase (Silva et al., 2006, J Membr Biol 212, 163-175). Activation of a signal cascade was evaluated by quantification of ERK1/2 phosphorylation by Western blot. Na(+),K(+)-ATPase activity was determined by electrophysiological techniques and expression by Western blot. Incubation of cells with ouabain induced activation of ERK1/2. Long-term incubation with ouabain induced an increase in Na(+) transepithelial flux and Na(+),K(+)-ATPase expression only in OK cells with 80 passages in culture. This increase was prevented by incubation with inhibitors of MEK1/2 and PI-3K. In conclusion, ouabain-activated signaling cascade mediated by both MEK1/2 and PI-3K is responsible for long-term regulation of Na(+) transepithelial flux in epithelial renal cells. OK cell line with high number of passages is suggested to constitute a particular useful model for the understanding of ouabain-mediated regulation of Na(+) transport.

Antigens from Leishmania amastigotes inducing clinical remission of psoriatic arthritis

A first generation vaccine (AS100-1) was manufactured with protein from four cultured Leishmania species, which proved to be effective in the treatment of psoriasis. A single blind trial on 3,132 psoriasis patients revealed 508 (16.2%) subjects with psoriatic arthritis (PsA) that received AS100-1 antigens. The study group was distributed according to percent psoriasis area and severity index (PASI) reduction from PASI 10 to PASI 100. All groups decreased in arthritis score (AS), tender joints counts and nail changes after treatment; the highest decreased in the PASI 100 group. Relapses of psoriasis and PsA had PASI and AS lower than initial values before treatment. Clinical remissions were at lower doses and less time, after the second course of treatment. Peripheral blood mononuclear cells (PBMC) lymphocyte subsets (LS) varied with PASI range (1-10, 11-20 and 21-72). Pre-treatment, absolute values of gated LS: CD4+, CD8+HLA-, CD8+HLA+, CD8+CD3-, CD8+CD3+ decreased in PBMC as PASI increased, suggesting migration from the blood to the skin. In contrary to the previous finding, the following LS: CD8+CD4-, CD3+CD8-, HLA+CD8-, CD19, CD8+CD4+ and membrane surface immunoglobulin IgA+, IgD+, IgM+, IgE+, and IgG+ increased in PBMC as PASI increased suggesting activation and proliferation by unknown antigens creating a homeostatic cycle between skin/joints and peripheral blood. After nine doses of AS100-1, the following LS: CD8+CD3+, CD8+HLA+, CD3+CD8-, CD4+CD8-, CD8+HLA-, HLA+CD8-, CD8+CD3-, CD19+, CD8+CD4-, CD8+CD4+, IgA+, IgD+, IgM+, IgE+, and IgG+ decreased significantly as compared with values before treatment. The LS decreased stops the vicious cycle between skin/joints and blood explaining clinical remission of lesions.

Use of early corticosteroid therapy on ICU admission in patients affected by severe pandemic (H1N1)v influenza A infection

INTRODUCTION

Early use of corticosteroids in patients affected by pandemic (H1N1)v influenza A infection, although relatively common, remains controversial.

METHODS

Prospective, observational, multicenter study from 23 June 2009 through 11 February 2010, reported in the European Society of Intensive Care Medicine (ESICM) H1N1 registry.

RESULTS

Two hundred twenty patients admitted to an intensive care unit (ICU) with completed outcome data were analyzed. Invasive mechanical ventilation was used in 155 (70.5%). Sixty-seven (30.5%) of the patients died in ICU and 75 (34.1%) whilst in hospital. One hundred twenty-six (57.3%) patients received corticosteroid therapy on admission to ICU. Patients who received corticosteroids were significantly older and were more likely to have coexisting asthma, chronic obstructive pulmonary disease (COPD), and chronic steroid use. These patients receiving corticosteroids had increased likelihood of developing hospital-acquired pneumonia (HAP) [26.2% versus 13.8%, p < 0.05; odds ratio (OR) 2.2, confidence interval (CI) 1.1-4.5]. Patients who received corticosteroids had significantly higher ICU mortality than patients who did not (46.0% versus 18.1%, p < 0.01; OR 3.8, CI 2.1-7.2). Cox regression analysis adjusted for severity and potential confounding factors identified that early use of corticosteroids was not significantly associated with mortality [hazard ratio (HR) 1.3, 95% CI 0.7-2.4, p = 0.4] but was still associated with an increased rate of HAP (OR 2.2, 95% CI 1.0-4.8, p < 0.05). When only patients developing acute respiratory distress syndrome (ARDS) were analyzed, similar results were observed.

CONCLUSIONS

Early use of corticosteroids in patients affected by pandemic (H1N1)v influenza A infection did not result in better outcomes and was associated with increased risk of superinfections.

Feeding associations between Guiana dolphins, Sotalia guianensis (Van Bénèden, 1864) and seabirds in the Lagamar estuary, Brazil

The main objective of the present study was to describe the characteristics regarding interactions between Guiana dolphins, Sotalia guianensis and seabirds in feeding associations in two distinct areas of the Lagamar estuary, Brazil. Boat-based surveys directed towards photo-identification studies of S. guianensis were conducted in the Cananéia Estuary (CE) (25 degrees 01' S and 47 degrees 55' W) from July 2004 to March 2008, as well as in the Paranaguá Estuarine Complex (PEC) (25 degrees 24' S and 48 degrees 24' W) from April 2006 to February 2008. On all occasions when seabirds were observed engaging in multi-species feeding associations with S. guianensis, data on species involved and their numbers were gathered. From 435 observed groups of S. guianensis in the CE, 38 (8.7%) involved interactions with seabirds. In the PEC, from the 286 observed groups, 32 (11.2%) involved the mentioned interactions. The following seabirds were observed in feeding associations with S. guianensis: Fregata magnificens, Sula leucogaster, Phalacrocorax brasilianus, and Sterna sp. In the CE, S. leucogaster was more commonly observed in feeding associations with Guiana dolphins (chi2 = 22.84; d.f. = 3, p < 0.05), while in the PEC no differences were reported when comparing seabird species (chi2 = 5.78; d.f.=3, p = 0.1223). In the CE, feeding associations were significantly more frequent in inner waters (subset A0; chi2 = 9.52; d.f. = 2, p < 0.05), and in winter (chi2 = 12.46; d.f. = 1, p < 0.05). Within these events, 44.7% of the association groups were composed by more than one seabird species. Seasonality in feeding associations was also observed in the PEC (chi2 = 4.76; d.f. = 1, p < 0.05), with same patterns observed in the CE. Interactions were more frequent in inner waters of the Laranjeiras bay, PEC (chi2 = 11.65; d.f. = 2, p < 0.05). Within these events, 74.2% of the association groups were composed by more than one seabird species. Water transparency, prey and seabird abundance and distribution, cetacean group size, and the life cycle of prey and seabirds are listed as the main factors addressing multi-species feeding associations in the Lagamar estuary.

Prostaglandin synthesis genes are differentially transcripted in normal and pyometra endometria of bitches

Pro-inflammatory stimuli, such as endotoxins released by Gram-negative bacteria, are potent stimulators of prostaglandin (PG) synthesis. The aim of this study was to evaluate the gene transcription pattern of PG synthesis enzymes in normal (anestrous, n = 6 and diestrous, n = 8) and pyometra (n = 7) endometria of bitches. Uteri were collected during routine ovariohysterectomy, processed for histopathological evaluation and uterine contents cultured. Gene transcription of COX-1, COX-2, mPGES-1 and PGF-synthase (PGFS) were evaluated by relative real-time PCR and normalized with the ribosomal protein L27 (RPL27) housekeeping gene. Normal uteri had no histological abnormalities and were negative for bacteriology. All pyometra uteri were hyperplasic and Escherichia coli was the only isolated bacterium. Except for COX-1, gene transcription was significantly higher in pyometra than in normal endometria. No significant differences in gene transcription were observed between normal diestrous and anestrous endometria. COX-2 gene transcription was 19 and 69 times higher in pyometra than in diestrous and anestrous endometria (p < 0.001), while PGFS gene transcription had a 3- and 600-fold increase in pyometra endometria compared to normal diestrous and anestrous endometria (p < 0.001). Gene transcription of mPGES-1 was 9 times higher in pyometra than in normal uteri (p < 0.01). Based on these results, we suggest that pyometra-associated E. coli endotoxin release stimulates the up-regulation of COX-2 PGFS and mPGES-1 gene transcription in the endometrium.

Group size and composition of Guiana dolphins (Sotalia guianensis) (Van Bénèden, 1864) in the Paranaguá Estuarine Complex, Brazil

The aim of the present study was to describe the characteristics of Guiana dolphins (S. guianensis) group size and composition in the Paranaguá Estuarine Complex (25° 15' -25° 36' S and 48° 02'-48° 45' W), Paraná State, as well as to verify the existence of relationships between a given environmental variable (water depth, salinity, transparency and temperature) and group size. An area of around 124 km² was surveyed by boat from April 2006 to February 2008 in the following subsets of the estuary: Canal do Superagui (~28 km²), Pinheiros bay (~34 km²), part of Laranjeiras bay, which included the Guaraqueçaba sub-estuary (~38 km²), and part of the Mixture Section of the Paranaguá Estuarine Complex (~24 km²). In 45 survey days, a total of 147 hours were spent observing 286 groups of S. guianensis. Groups varied from two individuals to aggregations of up to 90 individuals (mean ± SD: 11.5 ± 14.4 individuals). Solitary individuals were seen only on five occasions (1.7% of all observations). Groups with calves (n = 247) represented 86.4% overall and were more common in all sub-areas when compared to groups without calves. Groups without calves were found in all sub-areas and were usually smaller and composed of up to 12 individuals. A usual group composition of 70% of adults and 30% of calves was observed considering all sub-areas and seasons. No correlations were found between group size and water temperature (Spearman's rank test, r = 0.0059, p = 0.9338), transparency (Spearman's rank test, r = 0.0597, p = 0.9333), depth (Spearman's rank test, r = 0.1421, p = 0.4698), and salinity (Spearman's rank test, r = -0.1938, p = 0.0665). While Guiana dolphin groups were seen in the entire surveyed area, group size varied significantly among the three main surveyed sub-areas (Kruskal Wallis, H2,196 = 29.85, p = 0.0000). Groups were larger in Laranjeiras bay and smaller in Canal do Superagui. The physical environment, risk of predation, seasonal distribution and abundance of prey are the main possible factors driving larger groups in inner and protected waters.

Effect of interval to resynchronization of ovulation on fertility of lactating Holstein cows when using transrectal ultrasonography or a pregnancy-associated glycoprotein enzyme-linked immunosorbent assay to diagnose pregnancy status

The objective of this study was to compare 2 strategies for resynchronization of ovulation based on nonpregnant diagnoses using transrectal ultrasonography or a pregnancy-associated glycoprotein (PAG) ELISA. Lactating Holstein cows (n = 1,038) were submitted for first postpartum timed artificial insemination (TAI) using a Presynch + Ovsynch protocol. After the initial breeding, cows were randomly assigned to initiate resynchronization 25 d (D25) or 32 d (D32) later. Pregnancy status of cows initiating Resynch 25 d after TAI was determined 27 d after TAI by using a PAG ELISA, whereas pregnancy status of cows initiating Resynch 32 d after TAI was determined 39 d after TAI using transrectal ultrasonography. Cows diagnosed as not pregnant continued the Resynch protocol by receiving an injection of PGF(2 alpha) 7 d after the initial GnRH injection and a second GnRH injection 54 h after the PGF(2 alpha) injection. Cows in both treatments were inseminated approximately 16 h after the second GnRH injection. Blood samples for analysis of progesterone (P(4)) were collected at the first GnRH injection of each Resynch protocol. Pregnancies per AI (P/AI) of nonpregnant cows initiating Resynch 25 vs. 32 d after first postpartum TAI did not differ 39 d after TAI and were 28.3 vs. 30.9% for D25 vs. D32 cows, respectively. Mean P(4) at the first GnRH injection of Resynch was greater for D32 than for D25 cows (3.67 +/- 0.22 vs. 2.83 +/- 0.22 ng/mL), indicating that the Resynch treatments were initiated at different stages of the estrous cycle. After blocking P(4) concentration into low (<1.0 ng/mL) or high (>or=1.0 ng/mL) classes, P(4) class was not found to affect P/AI 39 d after TAI. Early resynchronization was not found to affect P/AI 39 d after TAI; however, early resynchronization did decrease days between inseminations and the interval from the initial nonpregnant diagnosis to conception. Earlier detection of nonpregnant cows using the PAG ELISA in conjunction with a TAI resynchronization program may improve the rate at which cows become pregnant in a dairy herd compared with transrectal ultrasonography conducted at a later stage after TAI.

Neuroendocrine (Merkel Cell) Carcinomas of the Skin: An Ultrastructural Study of Nine Cases

Nine neuroendocrine tumors of the skin were examined by light and electron microscopy. The patients (7 males and 2 females) had an average age of 57 years. Seven tumors were located in the head and neck region. Light microscopic examination showed sheets of cells. In 4 cases, a tendency to form small groups of cells was observed. Contact with the epidermis was seen in only 2 cases. The dominant ultrastructural feature was the presence of cytoplasmic processes that contained membrane-bound granules 100-200 nm. Three tumors recurred locally, and in 7 patients, regional nodal metastases occurred. Three patients died of disseminated disease.

Quantification of left ventricular asynchrony throughout the whole cardiac cycle with a computed algorithm: application for optimizing resynchronization therapy

INTRODUCTION

Measurement of left ventricular (LV) asynchrony is usually determined on single time points from spectral tissue Doppler imaging (TDI) scans that are frequently difficult to identify or not representative of the whole cardiac cycle. Our aim was to validate a new asynchrony index that evaluates the motion of the LV walls throughout the whole cardiac cycle.

METHODS AND RESULTS

Ten healthy volunteers and 50 patients undergoing cardiac resynchronization therapy (CRT) were studied with TDI. Wall displacement tracings from the septal and lateral LV walls were analyzed. Cross-correlation was calculated and 2 indices were obtained to assess LV asynchrony: the time delay and the superposition index (SI) between wall displacements. These results were compared between healthy volunteers and CRT patients, and between responders and nonresponders to CRT. Also, the optimal interventricular (VV) interval was based upon the best matching level. Volunteers showed lower asynchrony indices (83 +/- 2% SI, 17 +/- 8 ms time delay) as compared with CRT patients (63 +/- 15% SI, 73 +/- 60 ms time delay, P < 0.05). Responders also had more LV dyssynchrony than nonresponders (58 +/- 15% SI and 92 +/- 66 ms vs 68 +/- 12% and 48 +/- 34 ms, P < 0.05). The optimum VV interval selected by the computed algorithm showed an excellent concordance (Kappa = 0.90, P < 0.05) with that determined by other validated methods for optimizing the programming of CRT devices.

CONCLUSIONS

This approach allows measurement of LV intraventricular asynchrony throughout the cardiac cycle, being useful to determine the optimum VV interval and to select candidates for CRT.