Reviewing chemical and biological risks in urban agriculture: A comprehensive framework for a food safety assessment of city region food systems.

Attention to urban agriculture (UA) has recently grown among practitioners, scientists, and the public, resulting in several initiatives worldwide. Despite the positive perception of modern UA and locally grown, fresh produce, the potential food safety risks connected to these practices may be underestimated, leading to regulatory gaps. Thus, there is a need for assessment tools to evaluate the food safety risks connected to specific UA initiatives, to assist practitioners in self-evaluation and control, and to provide policy makers and scholars a means to pursue and assess food safety in city regions, avoiding either a lack or an excess of regulation that could ultimately hinder the sector. To address this aim, this paper reviews the most recent and relevant literature on UA food safety assessments. Food safety indicators were identified first. Then, a food safety assessment framework for UA initiatives was developed. The framework uses business surveys and food analyses (if available) as a data source for calculating a food safety index for single UA businesses and the whole UA landscape of a given city region. The proposed framework was designed to allow its integration into the CRFS (City Region Food System) toolkit developed by FAO (Food and Agriculture Organization of the United Nations), RUAF foundation (Resource Centres on Urban Agriculture and Food Security) and Wilfrid Laurier University.

Caspase-generated fragment of the Met receptor favors apoptosis via the intrinsic pathway independently of its tyrosine kinase activity.

The receptor tyrosine kinase Met and its ligand, the hepatocyte growth factor, are essential to embryonic development, whereas the deregulation of Met signaling is associated with tumorigenesis. While ligand-activated Met promotes survival, caspase-dependent generation of the p40 Met fragment leads to apoptosis induction - hallmark of the dependence receptor. Although the survival signaling pathways induced by Met are well described, the pro-apoptotic signaling pathways are unknown. We show that, although p40 Met contains the entire kinase domain, it accelerates apoptosis independently of kinase activity. In cell cultures undergoing apoptosis, the fragment shows a mitochondrial localization, required for p40 Met-induced cell death. Fulminant hepatic failure induced in mice leads to the generation of p40 Met localized also in the mitochondria, demonstrating caspase cleavage of Met in vivo. According to its localization, the fragment induces mitochondrial permeabilization, which is inhibited by Bak silencing and Bcl-xL overexpression. Moreover, Met silencing delays mitochondrial permeabilization induced by an apoptotic treatment. Thus, the Met-dependence receptor in addition to its well-known role in survival signaling mediated by its kinase activity, also participates in the intrinsic apoptosis pathway through the generation of p40 Met - a caspase-dependent fragment of Met implicated in the mitochondrial permeabilization process.

High-performance liquid chromatography with electrospray ionisation mass spectrometry and diode array detection in the identification and quantification of the degradation products of calix[4]arene crown-6 under radiolysis.

The extraction of 135Cs from high-activity liquid waste, arising from reprocessing of spent nuclear fuel, can be achieved by using calix[4]arene crown-6 compounds. The radiolytic degradation of di(n-octyloxy)calix[4]arene crown-6 (octMC6), in aliphatic or aromatic solvent in contact with 3 M nitric acid, was studied by high-performance liquid chromatography directly coupled to electrospray ionisation mass spectrometry (LC/ESI-MS). More than 50 distinct degradation products were observed, and about 30 of these were identified. These compounds can be assigned to three categories, namely, products of reactions involving radical cleavage or addition, of oxidation reactions, or of aromatic substitution reactions. The major product, corresponding to substitution by an NO2 group, was quantified by external standard calibration using a purified synthetic sample. Despite the observation of all these degradation compounds, octMC6 appears to be remarkably stable under these drastic conditions, combining hydrolysis (HNO(3) 3 M) and an extreme exposure to radiolysis (10(6) Gy). Less than 35% degradation of octMC6 was observed in aromatic solvent under these conditions.

Occurrence of two superoxide dismutases in Aeromonas hydrophila: molecular cloning and differential expression of the sodA and sodB genes.

Aeromonas spp., considered as emerging opportunistic pathogens, belong to the family Vibrionaceae. Among the criteria currently used for their classification is the presence of a single FeSOD (iron-containing superoxide dismutase), which distinguishes them from Enterobacteriacea. In this paper the cloning of the sodA and sodB genes encoding two different SODs in Aeromonas hydrophila ATCC 7966 is reported. The sodB gene encoded an FeSOD (196 amino acids, 21.5 kDa), was constitutively expressed and showed 75% homology with the E. coli FeSOD. The sodA gene encoded a protein of 206 amino acids (22.5 kDa) with MnSOD (manganese-containing SOD) activity and showed 55% homology with the Escherichia coli MnSOD. The MnSOD of A. hydrophila was detected only during the stationary phase of growth under high aeration or when induced by lack of iron. Nevertheless, paraquat had no detectable effect on its production. The amino-terminal part of the Mn-containing protein contained a putative signal sequence which could permit a periplasmic localization.

Expression patterns of the Ets transcription factors from the PEA3 group during early stages of mouse development.

erm, er81 and pea3 are three related genes that define a novel Ets-related subfamily of transcription factors. The expression patterns of these genes has been previously characterized in the mouse from embryonic day (E) 9.5 to birth (Oncogene 15 (1997) 937). In this study, we report differential expression patterns of the PEA3 group genes during early mouse post-implantation development. erm and pea3 expression patterns were partly overlapping. erm was activated prior to pea3 in the distal tip of the embryonic epiblast but, at primitive streak-stages, both genes were coexpressed in the posterior region of the embryo in epiblast, primitive streak and adjacent mesoderm. Similar erm and pea3 expression patterns were seen later in posterior neural plate, presomitic and lateral mesoderm, mesonephros, and tail bud. Only erm, however, was expressed in specific brain regions corresponding to prospective midbrain and ventral forebrain. erm was also strongly expressed as early as E8 in the developing branchial region, especially at the level of branchial pouches, whereas pea3 transcripts appeared later in frontonasal and first arch mesenchyme. er81 transcripts were not detected prior to E9.0-9.5, suggesting that this gene may not be involved in early developmental events.

Isolation of a member of ets gene family in the polychaete annelid Perinereis cultrifera.

Numerous genes belonging to the ets gene family have been described for a few years. The founder of this family is the v-ets proto-oncogene, which is the viral counterpart of the chicken c-ets-1 proto-oncogene. Main research was carried out both on Vertebrates, Drosophila and the nematod Caenorhabditis elegans. Previously, two genes of this family named Nd ets and Nd erg, were isolated in the polychaete annelid Hediste (Nereis) diversicolor. Here we have described the isolation of one gene from the ets family in another polychaete annelid named Perinereis cultrifera. By polymerase chain reaction using degenerated primers, we have amplified an approximatively 515 pb genomic region encoding the ETS domain and another domain designed as "R" domain by Qi et al. (1992) and which can mediate transactivation. By using this method for isolating members of the ets gene family, we are going to realize a phylogenetic study of the phylum of polychaete annelids.

The PEA3 group of ETS-related transcription factors. Role in breast cancer metastasis.

The ets genes encode eukaryotic transcription factors that are involved in tumorigenesis and developmental processes. The signature of the Ets family is the ETS-domain, which binds to sites containing a central 5'-GGAA/T-3' motif. They can be sub-classified primarily because of the high amino acid conservation in their ETS-domains and, in addition, in the conservation of other domains generally characterized as transactivating. This is the case for the PEA3 group, which is currently made up of three members, PEA3/E1AF, ER81/ETV1 and ERM, which are more than 95% identical in the ETS-domain and more than 85% in the transactivation acidic domain. The members of the PEA3 group are activated through both the Ras-dependent and other kinase pathways, a function which emphasizes their involvement in several oncogenic mechanisms. The expression pattern of the three PEA3 group genes during mouse embryogenesis suggests that they are differentially regulated, probably to serve important functions such as tissue interaction. Although the target genes of these transcription factors are multiple, their most frequently studied role concerns their involvement in the metastatic process. In fact, PEA3 group members are over-expressed in metastatic human breast cancer cells and mouse mammary tumors, a feature which suggests a function of these transcription factors in mammary oncogenesis. Moreover, when they are ectopically over-expressed in non-metastatic breast cancer cells, these latter become metastatic with the activation of transcription of matrix metalloproteinases or adhesion molecules, such as ICAM-1.

Occurrence of Leishmania infantum parasitemia in asymptomatic blood donors living in an area of endemicity in southern France.

Visceral leishmaniosis (VL) due to Leishmania infantum (L. chagasi) is a lethal disease if untreated, but asymptomatic L. infantum infections have been reported previously. A better understanding of parasite transmission, dissemination, and survival in the human host is needed. The purpose of this study was to assess whether L. infantum circulated in peripheral blood of subjects with no history of VL. Sera from 565 blood donors were screened by Western blotting to detect Leishmania-specific antibodies and identify individuals with probable past exposure to Leishmania. Seropositivity was found in 76 donors whose buffy coats were examined by PCR and direct culture. The parasite minicircle kinetoplast DNA was amplified from blood samples of nine donors. Promastigotes were detected by culture in blood samples from nine donors. Only two donors were PCR and culture positive. These results indicate that L. infantum circulates intermittently and at low density in the blood of healthy seropositive individuals, who thus appear to be asymptomatic carriers. Implications for the safety of blood transfusion are discussed.

Visceral leishmaniosis in HIV-positive patients: primary infection, reactivation and latent infection. Impact of the CD4+ T-lymphocyte counts.

OBJECTIVE: To discriminate cases of visceral leishmaniosis (VL) following a primary infection from cases originating in a reactivation of a latent Leishmania infection and to assess the impact of CD4+ T-cell counts on the occurrence of VL in patients with HIV disease. METHODS: We searched by Western blotting for the presence of Leishmania infantum-specific antibodies in the sera of 236 HIV-positive patients. We performed a follow-up of antileishmanial serology and analysed the evolution of the CD4+ T-cell counts for 14 HIV-positive VL patients and for 18 HIV-positive Leishmania-seropositive patients without VL. RESULTS: This study (1) showed that the VL disease/Leishmania infection ratio in HIV-positive individuals is high (1 : 10); (2) discriminated between a primary Leishmania infection (five patients who converted from Leishmania-seronegative to Leishmania-seropositive) and a reactivation of a latent infection (seven patients); (3) showed that HIV-positive individuals with dramatically low CD4+ T-cell counts maintained or generated a specific antileishmanial antibody production; (4) demonstrated that the primary-VL appeared at significantly higher (P = 0.028) CD4+ T-cell levels than the reactivation-VL; (5) documented the existence of HIV-positive Leishmania-seropositive individuals who despite a severe and prolonged immunosuppression did not develop VL (eight of 18). CONCLUSION: Our data stress the utility of the follow-up by Western blotting for an early diagnosis of VL, and therefore an early treatment, for HIV-positive patients living in endemic areas. They suggest that in a latent Leishmania infection supplementary control mechanism(s) might operate in addition to the T-cell-mediated response, and provide a further example of non-appearance of an opportunistic infection despite a severe reduction in CD4+ T cells.

Disseminated feline leishmaniosis due to Leishmania infantum in Southern France.

A fortuitously discovered case of feline leishmaniosis is reported. The parasites were found in the skin and the bone marrow of a domestic female cat that spontaneously died after a few weeks of evolution. Serological tests for FeLV, FIV and PIF virus detection gave negative results. By using Western blot serology, a characteristic pattern of leishmaniosis was obtained and by performing an isoenzyme electrophoresis, a Leishmania infantum MON-1 strain was identified. The same zymodeme is implicated in most of the canine and human leishmaniosis in Southern Europe. A study on the prevalence of asymptomatic feline leismaniosis is foreseen.

[Intra-mandibular adenoid cystic carcinoma]. / Carcinome adénoïde kystique intra-mandibulaire.

A case of mandibular cystic adenoid carcinoma was observed in a 49-year-old man. After slow progression, the diagnosis was directed to mandibular pseudocystic tumor. The treatment was enucleoresection. Histological findings in this exceptionnal lesion led to a discussion of the radioclinical diagnosis and etiopathogenic features of adenoide cystic carcinoma. The origin of this tumor is hypothesized to be heterotopic salivary inclusion although no histologicaly proof can be provided.

Short- and long-term efficacy of hexadecylphosphocholine against established Leishmania infantum infection in BALB/c mice.

In the immunocompetent host, visceral leishmaniasis (VL) is a fatal disease if untreated. In immunosuppressed patients, VL is an opportunistic infection for which there is no effective treatment for relapses. Here we report on the long-term activity of orally administered hexadecylphosphocholine (HDPC) against established Leishmania infantum infection in BALB/c mice. HDPC is a synthetic phospholipid with antiproliferative properties that has been extensively studied for its cancerostatic activity. Its short-term leishmanicidal effects in mice recently infected with viscerotropic Leishmania species have been previously reported. First, we show that 5 days of oral therapy with HDPC (20 mg/kg of body weight/day) led to amastigote suppression in the liver and the spleen of 94 and 78%, respectively (versus 85 and 55% suppression by meglumine antimonate in the liver and spleen, respectively), in mice infected 6 weeks before treatment and examined 3 days after the end of treatment. These results demonstrate the short-term efficacy of HDPC against an established Leishmania infection. Next, the long-term efficacy of HDPC was examined. In HDPC-treated mice both the hepatic and splenic amastigote loads were significantly reduced (at least 89%) 10, 31, and 52 days after the end of the treatment. In the treated mice, the increase of the splenic load was significantly slower than that in the untreated mice, demonstrating that the HDPC-exerted inhibition of Leishmania growth persisted for at least 7 to 8 weeks. Orally administered HDPC--the safe doses and side effects of which are at least partially known--appears to be a promising candidate for the treatment of VL.

Ontogeny of 17beta-hydroxysteroid dehydrogenase type 2 mRNA expression in the developing mouse placenta and fetus.

17beta-Hydroxysteroid dehydrogenase type 2 (17HSD type 2) catalyzes the inactivation of estradiol, testosterone and dihydrotestosterone into biologically less active 17-keto forms. Our recent Northern analysis indicated that the enzyme is expressed both in mouse placenta and fetus. The present data indicate that in the placenta the distribution of enzyme expression changes during pregnancy. In the choriovitelline placenta (day 8) 17HSD type 2 was expressed both in mural and polar giant cells. Later, on days 9-12.5, the mRNA was also detected in the junctional zone, and in late gestation (days 14.5-17.5), 17HSD type 2 mRNA was predominantly expressed only at the labyrinth region. In the fetus, 17HSD type 2 expression appears in the liver on day 11. At day 12 the expression was strongly increased in the liver, and at the same time moderate mRNA expression was also detected in the esophagus and intestine. In these tissues, high constitutive expression of 17HSD type 2 was then maintained throughout pregnancy. At later stages of development (days 15-16) the mRNA was, furthermore, detected in epithelial cells of the stomach, tongue, oropharynx and nasopharynx as well as in the kidney. We conclude that the expression pattern of 17HSD type 2 in the developing placenta and fetus suggests a role for the enzyme in maintaining a barrier to the transfer of active 17-hydroxy forms of sex steroids between the fetus and maternal circulation.

A conditional version of the Ets transcription factor Erm by fusion to the ligand binding domain of the oestrogen receptor.

The fusion of a wide range of proteins to the ligand-binding domain of nuclear receptors has been shown to impart ligand-dependent inducible activity of the resulting chimera. Transcriptional regulators of the ETS family are involved in both normal and oncogenic processes. In order to address the role of Erm, a "PEA3 subgroup" member of this family, we generated a chimera between Erm and the widely used ligand-binding domain of the oestrogen receptor (ER). The chimera, ErmER, consists of Erm protein fused at its C-terminal end to the ER domain. We show that ErmER displays a ligand-dependent transcriptional activity on ets responsive elements. The efficiency of ErmER mediated transactivation is modulated by the hormone concentration while its weak leakiness is reduced by using the steroidal anti-oestrogen EM-139. Our results define ErmER as the first conditional version of an Ets transcription factor, providing a useful tool to decipher Erm biological role and to identify potential Erm target genes.

Differential expression patterns of the PEA3 group transcription factors through murine embryonic development.

ERM, ER81 and PEA3 are three highly related transcription factors belonging to the ETS family. Together they form the PEA3 group within this family. Little data is yet available regarding the roles of these three genes during embryonic development. A prerequisite to investigations in this field is to obtain an accurate spatio-temporal expression map for the erm, er81 and pea3 genes. To this end, we have used in situ hybridization to compare their expression patterns during critical stages of murine embryogenesis. We report that all three genes are expressed in numerous developing organs coming from different embryonic tissues. The three genes appeared co-expressed in different organs but presented specific sites of expression, so that the resultant expression pattern could in fact reveal several distinct functions depending upon isolated and/or various combinations of the PEA3 member expression. These results suggest that erm, er81 and pea3 genes are differentially regulated, probably to serve important functions as cell proliferation control, tissue interaction mediator or cell differentiation, all over successive steps of the mouse organogenesis.

Detection by Western blot of four antigens characterizing acute clinical leishmaniasis due to Leishmania infantum.

Western blot analysis of sera from 32 patients with acute clinical leishmaniasis due to Leishmania infantum showed the simultaneous presence of antibodies against 4 antigens with molecular masses of 18, 21, 23, 31 kDa. The simultaneous presence of these 4 antigens was specific to the clinical disease and it was not detected in 47 sera from asymptomatic individuals living in the leishmaniasis endemic area of Alpes-Maritimes (southern France) or in 37 sera from patients with other protozoan infections.

Use of the leishmanin skin test and western blot analysis for epidemiological studies in visceral leishmaniasis areas: experience in a highly endemic focus in Alpes-Maritimes (France).

Fifty unselected subjects living in Alpes-Maritimes, France, a high risk area for visceral leishmaniasis due to Leishmania infantum, were examined simultaneously by the leishmanin skin test and the Western blot technique in 1993; 32% and 38%, respectively, gave a positive reaction. The concordance of the 2 methods was 82%. Thus, in this high risk area, a large proportion of inhabitants had been exposed to the parasite. The use of these 2 tests should permit the detection of potential cases of reactivated leishmaniasis in prospective follow-up investigations.