Addition of microbially-treated sugar beet residue and a native bacterium increases structural stability in heavy metal-contaminated Mediterranean soils

A mesocosm experiment was conducted to investigate the effect of the addition of Aspergillus niger-treated sugar beet waste, in the presence of rock phosphate, and inoculation with a native, metal-tolerant bacterium, Bacillus thuringiensis, on the stabilisation of soil aggregates of two mine tailings, with differing pH values, from a semiarid Mediterranean area and on the stimulation of growth of Piptatherum miliaceum. Bacterium combined with organic amendment enhanced structural stability (38% in acidic soil and 106% in neutral soil compared with their corresponding controls). Only the organic amendment increased pH, electrical conductivity, water-soluble C, water-soluble carbohydrates and plant growth, in both soils. While in neutral soil both organic amendment and bacterium increased dehydrogenase activity, only organic amendment had a significant effect in acidic soil. This study demonstrates that the use of P. miliaceum in combination with organic amendment and bacterium is a suitable tool for the stabilisation of the soil structure of degraded mine tailings, although its effectiveness is dependent on soil pH.

Cytokine expression by macrophages in the lung of pigs infected with the porcine reproductive and respiratory syndrome virus

Porcine reproductive and respiratory syndrome (PRRS) is caused by a virus that predominantly replicates in alveolar macrophages. The aim of the present study was to characterize the production of cytokines by subpopulations of pulmonary macrophages in pigs infected by the PRRS virus (PRRSV). Expression of interleukin (IL) 1α, IL-6 and tumour necrosis factor (TNF)-α correlated with the severity of pulmonary pathology and the numbers of pulmonary macrophages. Significant correlations were observed between PRRSV infection and the expression of IL-10, between the expression of IL-12p40 and interferon (IFN)-γ, and between the expression of TNF-α and IFN-γ. These findings suggest that PRRSV modulates the immune response by the up-regulation of IL-10, which may in turn reduce expression of cytokines involved in viral clearance (e.g. IFN-α, IFN-γ, IL-12p40 and TNF-α). The results also suggest that expression of IFN-γ is stimulated by IL-12p40 and TNF-α, but not by IFN-α. All of these cytokines were expressed mainly by septal macrophages with weaker expression by alveolar macrophages, lymphocytes and neutrophils. There appears to be differential activation of septal and alveolar macrophages in PRRSV infection, with septal macrophages being the major source of cytokines.

Soil acidity determines the effectiveness of an organic amendment and a native bacterium for increasing soil stabilisation in semiarid mine tailings

Unstable mine tailings are vulnerable to water and air erosion, so it is important to promote their surface stabilisation in order to avoid the spread of heavy metals. In a greenhouse experiment, we assessed the effect of the addition of Aspergillus niger-treated sugar beet waste and inoculation with a native bacterium, Bacillus cereus, on the stabilisation of soil aggregates of two acidic, semiarid mine tailings, with different acidity degree, during watering and drying periods. Organic amendment raised the pH of both the moderately and highly acidic tailings, whereas the bacterial inoculation increased this parameter in the former. Only the amendment addition increased soil water-soluble carbon in both tailings compared with their controls, under either watering or drying conditions. Both the amendment and B. cereus enhanced water-soluble carbohydrates. Both treatments increased dehydrogenase activity and aggregate stability, particularly in the moderately acidic tailing under drying conditions. After soil drying, aggregate stability was increased by the amendment (about 66% higher than the control soil) and by the bacterium (about 45% higher than the control soil) in the moderately acidic tailing. The effectiveness of these treatments as structure-stabilisation methods for degraded, semiarid mine ecosystems appears to be restricted to tailings of moderate acidity.

Endogenous lipid pneumonia in rats after subacute exposure to CdCl2

The objective of this report was to study lung cellular lesions in Wistar rats after subacute oral exposition to CdCl2. The experimental groups were exposed to CdCl2, through their drinking water in a concentration of 1 g/L, continuously for a period of 9 days. Histologically, all the exposed animals showed the incidence of interstitial pneumonia; hyperplasia of type II pneumocytes and Clara cells; the presence of foamy macrophages; and lesions linked to the existence of endogenous lipid pneumonia. Endogenous lipid pneumonia after CdCl2 exposure has not been previously described; and in its pathogenesis, hyperplasia of type II pneumocytes and Clara cells activation could play an important role.

Mineralocorticoid receptor antagonism attenuates cardiac hypertrophy and prevents oxidative stress in uremic rats

Chronic renal failure causes left ventricular hypertrophy, but the molecular mechanisms involved remain unknown. We, therefore, investigated whether the mineralocorticoid receptor is implicated in the cardiac hypertrophy observed in uremic rats and whether mineralocorticoid receptor blockade could be protective in chronic renal failure. Experimental groups were: control rats, uremic rats (NPX) with 5/6 nephrectomy (5 weeks), and NPX rats fed with spironolactone for 5 weeks. Systolic blood pressure was increased in both NPX rats and NPX rats fed with spironolactone for 5 weeks. Echocardiography revealed concentric left ventricular hypertrophy in uremia, which was attenuated by spironolactone. Enlarged cardiomyocyte size was observed in both left and right ventricles of NPX rats, an effect that was prevented by spironolactone. Mineralocorticoid receptor antagonism attenuated the increase of ventricular brain natriuretic peptide mRNA levels induced by nephrectomy. Left ventricular gene expressions of aldosterone synthase, mineralocorticoid receptor, and hydroxysteroid dehydrogenase type 2 were the same in the 3 groups, whereas gene expression of the glucocorticoid receptor was significantly diminished in chronic renal failure rats. No significant differences in cardiac aldosterone were observed between control rats and NPX rats, although NPX rats fed with spironolactone for 5 weeks showed increased plasma aldosterone levels. However, a significant increase in serum and glucocorticoid-inducible kinase-1 mRNA expression and protein was present in the NPX group; spironolactone treatment significantly reduced serum and glucocorticoid-inducible kinase-1 mRNA and protein in the left ventricle. Uremic rats exhibited a significant increase of superoxide production and reduced nicotinamide-adenine dinucleotide phosphate oxidase subunits expression (NOX-2, NOX-4, and p47(phox)) in the left ventricle, which was prevented by the mineralocorticoid receptor antagonist. Our findings provide evidence of the beneficial effects of spironolactone in cardiac hypertrophy and cardiac oxidative stress in chronic renal failure.

Occurrence of faecal contamination in households along the US-Mexico border

AIMS

The study aim was to determine the presence of total and faecal coliforms on kitchen surfaces, in tap water and on the hands of caregivers in households on both sides of the US-Mexico border.

METHODS AND RESULTS

Samples were collected in 135 randomly selected households in Ciudad Juarez, Mexico, and El Paso, Texas. Different surfaces throughout the kitchen and head of households' hands were sampled using sterile cotton swabs moistened in D/E neutralizing solution. Sponge/dishcloth and drinking water samples were also obtained. Total and faecal coliforms were enumerated on m-Endo LES and mFC respectively. Total coliforms and Escherichia coli in drinking water samples were enumerated in accordance with the Quanti-Tray method. Sponge/dishcloth samples were the most commonly contaminated kitchen sites, followed by countertops and cutting boards. We recovered faecal coliforms from 14% of the hands of child caregivers, and this indicator was moderately associated with self-reported failure to wash hands after using the toilet (OR = 3.2; 95% CI: 0.9, 11.1).

CONCLUSIONS

Hand washing should continue to be emphasized, and additional interventions should be directed to specific kitchen areas, such as sponges/dishcloths, tables/countertops and cutting boards.

SIGNIFICANCE AND IMPACT OF THE STUDY

There is a need for additional interventions regarding kitchen sanitation.

Endorphin responses to stress induced by competitive swimming event

AIM

The aim of the present study was to investigate the changes in endorphins (END) induced by swimming competitive practice.

METHODS

Twenty-three males, (13 trained swimmers [experimental group] and 10 sedentary and healthy students [age-matched comparison group]) took part in this investigation. The swimmers were assessed at 3 points: basal conditions, pre- and postswimming competition (100 m freestyle), whereas subjects from the control group only undertook the basal trial. The variables analysed were anxiety level, plasma END and lactate concentrations.

RESULTS

No statistical differences were observed in END basal levels between groups. An evident END response to precompetition psychological stress was observed in the experimental group, since the plasma END concentration rose from 36.3+/-2.9 pg/mL (basal conditions) to 51.8+/-3.2 pg/mL (P=0.05). The END response to the competitive effort produced a remarkable increase in its plasma concentration (128.6+/-18.1 pg/mL), showed statistical differences from precompetition (P=or<0.01) and from basal conditions (P=or<0.001). A significant rise in plasma lactate levels just at the end of the effort was found, although it did not correlate with END levels in the same situation.

CONCLUSION

Swimming competition (short-term maximal type of effort) induces a psychological and physiological stress, which stimulates the secretion of END. END are secreted to counter the negative effects of competitive stress, although more research is needed to accurate the relationship between END and anxiety levels during exercise.

Intestinal glandular inclusions (glandular choristoma) in the mesenteric lymph node of a goat

A glandular choristoma found in the mesenteric lymph node of a goat would appear to represent the first reported case of non-neoplastic glandular inclusions in domestic animals. The origin of this type of lesion may be difficult to determine, but in the present case cytokeratin expression patterns suggested that the inclusions had an intestinal origin.

Spontaneous trichoepithelioma in a laboratory mouse: gross, microscopic and immunohistochemical findings

A spontaneous trichoepithelioma occurred in a Swiss OF1 outbred, four-month-old, intact, nulliparous female mouse from a breeding colony. At necropsy, the tumour was a single, well-delineated mass measuring 4.2 cm in major diameter, located in the thoracic region and had an intact haired surface. The regional lymph nodes were not enlarged and no other abnormalities were found. Microscopically, it was composed of a random admixture of budding epithelial islands and cystic structures variable in size. The epithelial islands were composed of basaloid cells. The cystic structures were lined by squamous epithelium with or without a granular cell layer and contained lamellar or amorphous keratin, as well as wide areas of matrical keratinization (ghost cells) with or without a peripheral layer of basaloid cells and calcified contents. Mitotic activity of basaloid cells was moderate to high, but nuclear or mitotic atypia were not observed. High and low molecular weight cytokeratins, profilaggrin and involucrin expression were observed in the tumour. The immunohistochemical profile of this rare type of tumour of the skin of mice, which includes a first-time description of involucrin expression, confirms the histological evidence of differentiation towards more than one segment of follicular epithelium.

Endogenous Lipid Pneumonia in a Dog

Endogenous lipid pneumonia has previously been diagnosed in dogs only once. This report describes a case in a dog with a persistent cough, in which the histological diagnosis was based on the presence of numerous foamy macrophages that filled the alveoli and contained small sudanophilic vacuoles. The appearance of endogenous lipid pneumonia in this animal was accompanied by Dirofilaria immitis infection and chronic bronchitis.

Microbial processes in the rhizosphere soil of a heavy metals-contaminated Mediterranean salt marsh: a facilitating role of AM fungi

We investigated the relationship of the zonal pattern followed by the vegetation in a polluted Mediterranean salt marsh, in semiarid south-eastern Spain, with the microbiological and biochemical properties (labile C fractions, oxidoreductases and hydrolases) of the rhizosphere soil of two halophyte species, Arthrocnemum macrostachyum and Sarcocornia fruticosa, and with the degree of arbuscular mycorrhizal (AM) colonisation in their rhizospheres. Levels of plant biomass and cover were inversely related to heavy metal contents and salinity. The concentrations of Fe, Cu, Mn and Pb extracted with DTPA hardly varied among the different zones of the salt marsh. The dehydrogenase and phosphatase activities, the soluble C and water-soluble carbohydrates concentrations and the extent of root colonisation were greater in the salt marsh zones of lower soil salinity and lower metal concentration. Urease and beta-glucosidase activities were not detected in the salt marsh. Plant biomass and cover showed positive relationships with mycorrhizal colonisation (R=0.773, P<0.001; R=0.874, P<0.001, respectively). Mycorrhizal colonisation was negatively correlated with the contents of Pb and Zn in plant tissues. This work supports the view that reduced plant uptake of toxic metals, particularly lead, could be involved in the beneficial effects of AM fungi on plant development in Mediterranean salt marshes contaminated with mining wastes.

Fatal toxoplasmosis and concurrent Calodium hepaticum infection in Korean squirrels (Tanias sibericus)

Four Korean squirrels (Tanias siberius) imported in Spain from People's Republic of China died 2 days after their arrival at a pet shop. They had neurological signs associated with generalized toxoplasmosis involving brain, lungs, liver, and the heart. Toxoplasma gondii-like tachyzoites and tissue cysts were found in organs of all four squirrels. The protozoa stained positively with T. gondii polyclonal antibodies and were ultrastructurally similar to T. gondii. Calodium (Capillaria) hepaticum infection was found in the liver of one squirrel.

A novel mutation (G114V) in the prion protein gene in a family with inherited prion disease

Inherited prion diseases are characterized by mutations in the PRNP gene encoding the prion protein (PrP). We report a novel missense mutation in the PRNP gene (resulting in a G114V mutation in PrP) in members of a Uruguayan family with clinical and histopathologic features of prion disease. Affected individuals were characterized by an early age at onset, initial neuropsychiatric symptoms, late dementia with prominent pyramidal and extrapyramidal symptoms, and long disease duration.

Expression of proinflammatory cytokines by hepatic macrophages in acute classical swine fever

Fourteen pigs were inoculated with the 'Alfort 187' strain of classical swine fever (CSF) virus and killed in pairs at 2, 4, 7, 9, 11, 14 or 17 days post-inoculation for histopathological, ultrastructural and immunohistochemical examination. For the latter method, the antibodies used were those against viral antigen Gp55, porcine myeloid marker SWC3, IL-1alpha, IL-6, TNF-alpha and Factor VIII-related antigen. Activation and increase in the number of hepatic macrophages was observed following viral detection in liver, as well as an increase in IL-1alpha and IL-6 production, mainly by Kupffer cells. Maximum detection of viral antigen was observed in the middle stage of the experiment coinciding with overexpression of the three cytokines studied, with IL-6 production by interstitial macrophages prominent at the end. Additionally, the labelling of platelets for Factor VIII-related antigen and the ultrastructural study of the sinusoids revealed activation and aggregation of thrombocytes close to Kupffer cells at the beginning of the infection. The liver seems to play a prominent role in the origin of the thrombocytopenia that occurs in CSF and contributes to the overexpression of proinflammatory cytokines considered responsible for the disorders observed during the course of the disease.

Evolution of T Lymphocytes and Cytokine Expression in Classical Swine Fever (CSF) Virus Infection

This study characterized the cell-mediated immune response in pigs inoculated with the Alfort 187 isolate of classical swine fever (CSF) virus. Quantitative changes in the T-lymphocyte population (CD3(+), CD4(+) and CD8(+)) and qualitative changes in cytokine expression (IL-2, IL-4 and IFNgamma) by these cells in serum, thymus and spleen were demonstrated. These changes coincided spatially and temporally with previously described quantitative and qualitative changes in monocyte-macrophage populations, thus demonstrating the contribution of the two cell populations to lymphoid depletion. Moreover, examination of cytokine expression in thymus and spleen samples revealed a type 1 cell-mediated immune response in the early and middle stages of the experiment, giving way to a type 2 immune response towards the end of the experiment; these findings, which accorded with the serological results and lymphopenia, may influence the delayed humoral response characteristic of CSF.

Immunohistochemical Detection of the Expression of Pro-inflammatory Cytokines by Ovine Pulmonary Macrophages

The aim of this study was to determine the expression of three proinflammatory cytokines by pulmonary macrophages of sheep in paraffin wax-embedded tissue. Samples of lung from seven healthy sheep were fixed by immersion in either 10% neutral buffered formalin, acetic formalin, paraformaldehyde-lysine-periodate or Bouin's solution and processed for structural and immunohistochemical studies. The expression of interleukin (IL)-1alpha, IL-6 and tumour necrosis factor (TNF)-alpha by pulmonary intravascular macrophages (PIMs) and alveolar macrophages (AMs) was detected by the avidin-biotin-peroxidase (ABC) technique. Bouin's solution proved to be the most suitable fixative and Tween 20 the most effective pretreatment for increasing permeability. Constitutive expression of IL-1alpha, IL-6 and TNF-alpha by both macrophage populations was detected. The number of PIMs expressing IL-1alpha (the predominant cytokine in ovine lung) was higher than that of AMs, while the expression of IL-6 was greater in AMs. No differences between PIMS and AMs were found in respect of TNF-alpha expression. The evaluation of cytokine expression represents a valuable tool for studying the pathogenesis of disease in the ovine lung.

Insulin-like growth factor-1 induces an inositol 1,4,5-trisphosphate-dependent increase in nuclear and cytosolic calcium in cultured rat cardiac myocytes

In the heart, insulin-like growth factor-1 (IGF-1) is a pro-hypertrophic and anti-apoptotic peptide. In cultured rat cardiomyocytes, IGF-1 induced a fast and transient increase in Ca(2+)(i) levels apparent both in the nucleus and cytosol, releasing this ion from intracellular stores through an inositol 1,4,5-trisphosphate (IP(3))-dependent signaling pathway. Intracellular IP(3) levels increased after IGF-1 stimulation in both the presence and absence of extracellular Ca(2+). A different spatial distribution of IP(3) receptor isoforms in cardiomyocytes was found. Ryanodine did not prevent the IGF-1-induced increase of Ca(2+)(i) levels but inhibited the basal and spontaneous Ca(2+)(i) oscillations observed when cardiac myocytes were incubated in Ca(2+)-containing resting media. Spatial analysis of fluorescence images of IGF-1-stimulated cardiomyocytes incubated in Ca(2+)-containing resting media showed an early increase in Ca(2+)(i), initially localized in the nucleus. Calcium imaging suggested that part of the Ca(2+) released by stimulation with IGF-1 was initially contained in the perinuclear region. The IGF-1-induced increase on Ca(2+)(i) levels was prevented by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-AM, thapsigargin, xestospongin C, 2-aminoethoxy diphenyl borate, U-73122, pertussis toxin, and betaARKct (a peptide inhibitor of Gbetagamma signaling). Pertussis toxin also prevented the IGF-1-dependent IP(3) mass increase. Genistein treatment largely decreased the IGF-1-induced changes in both Ca(2+)(i) and IP(3). LY29402 (but not PD98059) also prevented the IGF-1-dependent Ca(2+)(i) increase. Both pertussis toxin and U73122 prevented the IGF-1-dependent induction of both ERKs and protein kinase B. We conclude that IGF-1 increases Ca(2+)(i) levels in cultured cardiac myocytes through a Gbetagamma subunit of a pertussis toxin-sensitive G protein-PI3K-phospholipase C signaling pathway that involves participation of IP(3).