Multigenerational tests on Daphnia spp.: a vision and new perspectives.

Multigenerational toxicity testing is a valuable tool for understanding the long-term effects of contaminants on aquatic organisms. This review focuses on the use of multigenerational tests with Daphnia, a widely used model organism in aquatic toxicological studies. The review highlights the importance of studying multiple generations to assess Daphnia spp. reproductive, growth, and physiological responses to various contaminants. We discuss the outcomes of multigenerational tests involving different contaminants, including nanoparticles, pesticides, and pharmaceuticals. The results reveal that multigenerational exposure can lead to transgenerational effects, where the impacts of contaminants are observed in subsequent generations even after the initial exposure has ceased. These transgenerational effects often manifest as reproduction, growth, and development alterations. Furthermore, we emphasize the need for standardized protocols in multigenerational testing to ensure comparability and reproducibility of results across studies. We also discuss the implications of multigenerational testing for ecological risk assessment, as it provides a more realistic representation of the long-term effects of contaminants on populations and ecosystems. Overall, this review highlights the significance of multigenerational tests with Daphnia in advancing our understanding of the ecological impacts of contaminants. Such tests provide valuable insights into the potential risks associated with long-term exposure to pollutants and contribute to the development of effective mitigation strategies for aquatic ecosystems.

Temporal changes in total and metabolically active ruminal methanogens in dairy cows supplemented with 3-nitrooxypropanol.

The purpose of this study was to investigate the effect of 3-nitrooxypropanol (3-NOP), a potent methane inhibitor, on total and metabolically active methanogens in the rumen of dairy cows over the course of the day and over a 12-wk period. Rumen contents of 8 ruminally cannulated early-lactation dairy cows were sampled at 2, 6, and 10 h after feeding during wk 4, 8, and 12 of a randomized complete block design experiment in which 3-NOP was fed at 60 mg/kg of feed dry matter. Cows (4 fed the control and 4 fed the 3-NOP diet) were blocked based on their previous lactation milk yield or predicted milk yield. Rumen samples were extracted for microbial DNA (total) and microbial RNA (metabolically active), PCR amplified for the 16S rRNA gene of archaea, sequenced on an Illumina platform, and analyzed for archaea diversity. In addition, the 16S copy number and 3 ruminal methanogenic species were quantified using the real-time quantitative PCR assay. We detected a difference between DNA and RNA (cDNA)-based archaea communities, revealing that ruminal methanogens differ in their metabolic activities. Within DNA and cDNA components, methanogenic communities differed by sampling hour, week, and treatment. Overall, Methanobrevibacter was the dominant genus (94.3%) followed by Methanosphaera, with the latter genus having greater abundance in the cDNA component (14.5%) compared with total populations (5.5%). Methanosphaera was higher at 2 h after feeding, whereas Methanobrevibacter increased at 6 and 10 h in both groups, showing diurnal patterns among individual methanogenic lineages. Methanobrevibacter was reduced at wk 4, whereas Methanosphaera was reduced at wk 8 and 12 in cows supplemented with 3-NOP compared with control cows, suggesting differential responses among methanogens to 3-NOP. A reduction in Methanobrevibacter ruminantium in all 3-NOP samples from wk 8 was confirmed using real-time quantitative PCR. The relative abundance of individual methanogens was driven by a combination of dietary composition, dry matter intake, and hydrogen concentrations in the rumen. This study provides novel information on the effects of 3-NOP on individual methanogenic lineages, but further studies are needed to understand temporal dynamics and to validate the effects of 3-NOP on individual lineages of ruminal methanogens.

Invasive fungal infections in Argentine patients with systemic lupus erythematosus.

INTRODUCTION: Infections are the leading cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Invasive fungal infections (IFI) comprise a group of diseases caused by Cryptococcus, Histoplasma, Aspergillus and Candida. Few studies of IFI have been published in patients with SLE and associated factors have not been completely defined. OBJECTIVES: The objectives of this paper are to estimate the frequency of IFI in admitted patients with SLE in our hospital, to determine the risk factors associated with IFI in our patients with SLE, and to compare IFI group with a control group (SLE without IFI). METHODS: The medical charts of patients with IFI (EORTC/MSG, 2008) and SLE (ACR, 1997) admitted to our hospital from June 2001 until June 2012 were reviewed. To identify factors associated with IFI, we developed a case-control study (SLE + IFI vs SLE alone) in a one to three ratio adjusted for sex and age and hospitalization for other reasons. Comparison was made of demographic characteristics, duration of disease and disease activity previous to IFI diagnosis, especially three months before fungal infection. We defined severe activity as SLEDAI ≥ 8. Infection by fungi of the genus Candida was considered only in its disseminated form. RESULTS: Ten cases of IFI were identified in 208 patients with SLE admitted between June 2001 and June 2012. We included 40 patients with SLE (10 with IFI and 30 controls). Of the SLE-IFI patients, eight were women and the average age was 27.5 years (range, 19-42 years). Fungal isolation: eight Cryptococcus neoformans, one Histoplasma capsulatum and one Candida albicans. Sites affected: five in peripheral blood, five in central nervous system (CNS), four in skin/soft tissue and one in pleura. Mortality was 40% (p = 0.002), with Cryptococcus neoformans being the most common fungus. The SLE disease activity was severe in 70% of infected patients and no significant difference with the control group was found (p = 0.195). We also found no association with leukopenia, lymphopenia, hypocomplementemia, hypogammaglobulinemia or anti-DNA positivity; neither with meprednisone doses >20 mg/day or intravenous methylprednisolone pulse therapy before fungal infection. The use of immunosuppressive therapy with azathioprine showed a significant association (p = 0.017). Cyclophosphamide (p = 0.100) or mycophenolate mofetil (p = 0.256) did not show similar results. CONCLUSION: The frequency of IFI in hospitalized SLE patients in our hospital was 4.8%. Cryptococcus neoformans was the most common etiologic agent and was primarily responsible for the deaths in this cohort. These data are consistent with publications in East Asia rather than North America where Candida spp. is more common. Unlike other publications, previous immunosuppression with azathioprine was the only risk factor associated with the development of the infection. Invasive fungal infection should be suspected in hospitalized patients with SLE and immunosuppression with CNS or atypical cutaneous manifestation of SLE in order to start appropriate treatment early and obtain better outcome.

Tercer reporte de eventos adversos con tratamientos biológicos en Argentina. Informe de registro biobadasar / Thrid report of adverse events with biologics in Argentina. Report from biobadasar registry

Introducción: BIOBADASAR (Registro Argentino de Eventos Adversos con Tratamientos Biológicos en Reumatología) comenzó en agosto de 2010. La importancia de este registro es mostrar datos locales que, probablemente, puedan diferir de otros registros. El objetivo es comunicar los resultados del tercer reporte de BIOBADASAR. Métodos: Todos los pacientes con enfermedades reumáticas que requirieron tratamiento con agentes biológicos y pacientes controles sin estos tratamientos fueron incluidos en la base de datos provenientes de 32 centros participando a lo largo de la Argentina. Tres áreas de datos son analizados: características de los pacientes, tratamientos y eventos adversos...

Introduction: BIOBADASAR (Argentine Registry of Adverse Events with Biological Treatments in Rheumatology) began in August 2010. The importance of this registry is to show local data that may probably differ from other registries. The objective is to communicate the results of the third BIOBADASAR report. Methods: All patients with rheumatic diseases who required treatment with biological agents and control patients without these treatments were included in the database from 32 participating centers throughout Argentina. Three areas of data are analyzed: patient characteristics, treatments and adverse events...

Isolation and characterization of an endonuclease synthesized by barley (Hordeum vulgare L.) uninucleate microspores.

Few biochemical and molecular details are available on microspore growth and development. In this work, a nuclease was partially purified from diffusates of barley (Hordeum vulgare L.) microspores by using concanavalin-A as ligand. The chromatographic preparation contained a 34-kDa protein with nucleolytic activity; the enzyme (called BMN: barley microspore nuclease) was very stable at pH > 8.0 and temperatures below 50 degrees C. Activity was highest at pH 5.6 and increased almost exponentially with temperature until a breakpoint between activity and stability was reached at 70 degrees C. Although BMN was able to cleave RNA, the enzyme showed a remarkable preference for DNA, especially in the single-stranded form. The best homopolymeric substrates were poly(dA) and poly(A), whereas poly(dC), poly(G) and poly(I) were almost completely uncleaved. When incubated with intact nuclei, BMN caused a nucleosomal DNA ladder of approximately 200 bp. On the basis of DNA laddering, substrate specificity, Mg2+ -dependence and best performance at apoplastic pH, BMN can be referred to as a putative apoptotic nuclease involved in pollen development.

Detection and subcellular localization of an AML1 chimeric protein in the t(8;21) positive acute myeloid leukemia.

AML1, a gene encoding a protein of the PEBP2/CBF family of transcription factors is disrupted by translocations associated with human leukemia. In the t(8;21) acute myelogenous leukemia (AML), AML1 was found fused to a gene on chromosome 8 that we designated CDR (also known as ETO and MTG8). Immunoprecipitation experiments followed by immunoblotting using a combination of antibodies against different epitopes of one of the predicted chimeric proteins encoded by a fully characterized fusion transcript enabled us to visualize a chimeric protein in the t(8;21) Kasumi-1 cell line. The estimated size of this protein is 64 kDa. Immunoblotting of leukemic blasts containing the t(8;21) detected a protein of the same size. Immunofluorescence experiments indicate that the chimeric protein is localized in the nucleus. A normal AML1 protein of 27 kDa was also detected in t(8;21) Kasumi-1 cells. It remains to be established by which mechanism the mutant AML1 isoform may contribute to the leukemogenesis process of t(8;21)-positive acute myeloid leukemia.

Heat shock response in the liver: expression and regulation of the hsp70 gene family and early response genes after in vivo hyperthermia.

Heat shock response in cultured cells has been studied extensively; however few data are available on heat shock response in an intact organ of a living animal. In this study we analyzed the kinetics of expression of the heat shock protein 70 gene family (heat shock protein 70, heat shock cognate protein 73 and glucose-regulated protein 78) in the liver of the thermally stressed rat. New synthesis of heat shock protein 70 and heat shock cognate protein 73 was shown in liver slices pulse labeled in vitro with 35S-methionine. Accumulation of heat shock protein 70 and heat shock cognate protein 73 proteins was shown in total cellular extracts. 32P-labeled complementary DNA probes encoding heat shock protein 70, heat shock cognate protein 73 and glucose-regulated protein 78 were used to show that the levels of the corresponding messenger RNAs increase as a fraction of total RNA and in polysomes at different extents and with different kinetics. The induction of heat shock protein 70 and heat shock cognate protein 73 messenger RNAs reflected the increase in the synthesis of the corresponding proteins. Run-on transcription analysis indicated that the expression of heat shock protein 70 and heat shock cognate protein 73 genes was mainly regulated at the transcriptional level. On the contrary, both transcriptional and posttranscriptional regulatory mechanisms can explain the induction of the glucose-regulated protein 78 gene.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein synthesis and gene expression in transplanted and postischemic livers.

The expression of some genes has been comparatively studied in transplanted rat liver and in liver reperfused after ischemia in situ. Experiments on protein synthesis by tissue slices from cold-stored or transplanted livers show that rat livers that retain a good capacity for protein synthesis during storage undergo a profound impairment in the capacity for protein synthesis during the first hours after transplantation. This recovers in the following hours. There is never any indication of synthesis of stress proteins, and of hsp 70 in particular. The steady-state level of mRNAs for albumin, transferrin, and beta-actin, which are well expressed in reperfused postischemic livers in vivo, are reduced early after transplantation and recover only many hours later. Run-on analysis shows that an early defect in transcription and a partial recovery of this process later on are responsible for these changes. The steady-state levels of the same mRNAs are well maintained in donor livers preserved in University of Wisconsin solution for at least 12 hr, and less satisfactorily in Euro-Collins solution. Results of run-on analysis parallel the data on mRNA levels. The behavior of these mRNAs is, therefore, clearly different in reperfused and transplanted liver. The early stages of liver transplantation seem to be characterized by a depressed capacity of gene expression, without the reactive phenomenon of activation of stress protein genes that occurs in reperfused postischemic livers.

Expression of HSP 70, immediate-early response and heme oxygenase genes in ischemic-reperfused rat liver.

BACKGROUND: Reperfusion of the liver after non-necrogenic ischemia induces the expression of the HSP gene and the synthesis of the hsp 70 protein, the best known among stress (heat-shock) proteins. EXPERIMENTAL DESIGN: We have studied the time course of the induction and the effects of cycloheximide treatment on the expression of c-fos, c-jun and the heat-shock gene HSP 70 in ischemic-reperfused livers; extracts of these livers have also been examined for the binding to a synthetic oligonucleotide containing the heat-shock consensus sequence (HSE) in order to reveal the possible presence of an active heat-shock factor (HSF) in ischemic-reperfused tissue. RESULTS: Expression of HSP 70 gene appears only after a certain threshold of cell damage, is preceded by induction of c-fos and c-jun but does not depend on ongoing protein synthesis. The binding of HSF to HSE seems to start during the late period of ischemia, although the subsequent reperfusion increases the effect. The level of heme-oxygenase mRNA, an indicator of oxidative stress, increases in the liver after reperfusion but the oxidative stress caused by CoCl2 treatment does not induce the expression of HSP 70 gene under the conditions of the present experiments. CONCLUSIONS: We suggest that, similar to heat-shock, protein malfolding occurring during ischemia may trigger the HSP 70 gene induction, which is then amplified by the subsequent reperfusion stress. A model of chemically induced oxidative stress seems to be unable to induce the HSP 70 gene expression with the same characteristics of heat shock or ischemia-reperfusion.

Expression of the HSP 70 gene family in rat hepatoma cell lines of different growth rates.

We have studied the expression of different members of the HSP 70 gene family in MH1C1, FAO, and 3924A hepatoma cell lines, which possess different growth rates and show different levels of histone H3 gene expression. The cells have been subjected to mild (42 degrees C/1 h) or severe (45 degrees C/25 min) heat shock that causes a decrease in cell proliferation and histone H3 gene expression correlated to the severity of stress: previous mild heat shock protects against the effects of the subsequent severe exposure. All cell lines, irrespective of their growth rate, show a high constitutive expression of the HSC 73 gene, which is barely detectable in normal liver, and a good induction of the heat-inducible HSP 70 gene, which, however, seems to be induced less than in the normal tissue. The relative amount of grp 78 mRNA is high in all hepatoma cells lines, but only FAO cells maintain a significant expression of the albumin gene. The basic diversity in HSP 70 family gene expression between normal and tumors is still maintained in hepatoma cell lines, but the growth-related, quantitative differences among the transplantable hepatomas that we previously found in the animal (Bardella et al., Br. J. Cancer 55, 642-645, 1987; Cairo et al., Hepatology 9, 740-746, 1989), seem to be lost, or at least strongly blunted, in vitro.

Action of clindamycin-phosphate in foreign body infections due to Staphylococcus epidermidis in mice.

The virulence of Staphylococcus epidermidis strain slime producer was examined in an experimental model of foreign body infection in mice. In the course of this experimental infection the mice were injected with two antibiotics (clindamycin and cefazolin) active in vitro toward the Staphylococcus strain used. The results obtained after a week of antibiotic therapy show that clindamycin alone has a therapeutic action against the infection caused by S. epidermidis. Cefazolin showed a very poor therapeutic effect. The results are discussed on the basis of inflammatory reaction elicited from the foreign body and the characteristics of clindamycin in connection with the host's defense mechanisms.

Evaluation of antinfective activity of an association bifidobacterium/lactobacillus in mouse intestine.

The present research aimed at studying the action of an association of Bifidobacterium bifidum and Lactobacillus acidophilus, in controlling an experimental severe infection by Salmonella enteritidis administered in mouse per os. The behaviour of some parameters was undertaken, checking for the pH of intestinal content; the condition of the colonization in the intestinal wall by means of scanning electron microscopy and plates cultures; the presence of antibodies IgA in intestinal content; the index of mortality in the diversely treated animal's groups. The reported data show a string incidence of the administration of Bifidobacterium and Lactobacillus in increasing the animal's resistance against the lethal infection.

[Bactericidal and potent antiadhesive activity of sulbenicillin]. / Studio dell'attivita battericida di sulbenicillina e del suo potere antiaderente.

Sulbenicillin, a wide broad spectrum penicillin, is active against a lot of gram positive and gram negative bacteria. The AA. studied the activity of this molecule against urinary infections causing germs, by evaluating two parameters: his antiadhesive capability and the Killing curves, in comparison with mezlocillin and piperacillin. An inhibition in adhesive capability of test-germs, due to sulbenicillin was obtained. Furthermore, resulting Killing curves showed more rapidity in action for sulbenicillin than for the two others molecules, versus resistant germs, like P. aeruginosa and S. faecalis.

[Interference of the intestinal ecosystem of mice in the oral administration of lyophilized live bacteria]. / Interferenza sull'ecosistema intestinale di topo della somministrazione orale di batteri vivi liofilizzati.

Oral vaccines mode by living or killed bacteria are commonly used to restore normal intestinal flora; it's not well know, however, which bacteria play the leading part in this ecosystem. In the present paper Authors have intended to compare the effectiveness of an oral vaccine, made by Bifidobacterium bifidus and Lactobacillus acidofilus, with another of similar use, made by Enterococci, to increase the mouse resistance to lethal Salmonella enteritidis infections. According to collected microbiological data and M.E.S. photos, the association Bifidob./Lactobac. is more effective than Enterococci to enhance resistance to the experimental infection.

Synergic activity of beta-lactamines and aminoglycosides vs. bacterial strains treated with sub-MIC concentrations.

The aim of the present paper was to evaluate the interaction between beta-lactamines and aminoglycosides against Gram-positive and Gram-negative bacteria previously treated with sub-inhibitory doses of each antibiotic in the combination. Bacterial strains were: S. aureus ATTC 25923, S. mitis NCTC 3165, E. coli ATTC 25922, P. vulgaris ATTC 13315. Antibiotics used were penicillin G and gentamicin. The most synergistic combination was the ratio of 4 (penicillin G) to 1 (gentamicin) before and after sub-MIC treatment with penicillin.