Functional role of phenylacetic acid from metapleural gland secretions in controlling fungal pathogens in evolutionarily derived leaf-cutting ants

Fungus-farming ant colonies vary four to five orders of magnitude in size. They employ compounds from actinomycete bacteria and exocrine glands as antimicrobial agents. Atta colonies have millions of ants and are particularly relevant for understanding hygienic strategies as they have abandoned their ancestors'' prime dependence on antibiotic-based biological control in favour of using metapleural gland (MG) chemical secretions. Atta MGs are unique in synthesizing large quantities of phenylacetic acid (PAA), a known but little investigated antimicrobial agent. We show that particularly the smallest workers greatly reduce germination rates of Escovopsis and Metarhizium spores after actively applying PAA to experimental infection targets in garden fragments and transferring the spores to the ants'' infrabuccal cavities. In vitro assays further indicated that Escovopsis strains isolated from evolutionarily derived leaf-cutting ants are less sensitive to PAA than strains from phylogenetically more basal fungus-farming ants, consistent with the dynamics of an evolutionary arms race between virulence and control for Escovopsis, but not Metarhizium. Atta ants form larger colonies with more extreme caste differentiation relative to other attines, in societies characterized by an almost complete absence of reproductive conflicts. We hypothesize that these changes are associated with unique evolutionary innovations in chemical pest management that appear robust against selection pressure for resistance by specialized mycopathogens.     

Gross (mesoscopic) and applied anatomy of the anterior inferior cerebellar artery in man with special reference to its course through the cerebellopontine angle region.

In the present paper, we describe anatomical variants of the anterior inferior cerebellar artery in man for applicative purposes. Our goal was to provide the surgeon with a detailed anatomical view of the region. This is similar to what he may observe through the surgical microscope using modern microsurgical techniques. We have focused our attention on the segments of the artery comprising its origin, its course until it reaches the cerebellum and its main collateral branches. Our results confirm the great variability of the elements under study, but enable the establishment of a few basic variational patterns. These patterns together with their relative frequency may be helpful in microsurgery.     

Widely Used Enhancer of Eukaryotic Expression Vectors Is Strongly and Differentially Regulated in Fibroblast, Myoblast, and Teratocarcinoma Cell Lines

The expression of transgenes in eukaryotic cells is a powerful approach in cell biology. In most cases, it is based on the activity of strong and constitutive viral cis-acting elements in eukaryotic expression vectors. Here we show that a widely used such element derived from an early gene of human cytomegalovirus is strongly and differentially regulated in mouse cell lines. We analyzed cytomegalovirus promoter-driven expression of stably transfected transgenes in growing, confluent, and differentiating mouse 3T3 fibroblasts, C2C12 myoblasts, and P19 teratocarcinoma cells. In the fibroblasts, transgene expression was strongly downregulated in confluent cultures and was upregulated in growing or confluent cultures by phorbol ester. In contrast, no downregulation by confluency, nor upregulation by phorbol ester, was detected in C2C12 cells. In addition, while marked upregulation was detected in differentiating myotubes, transgene expression was downregulated when differentiating teratocarcinoma cells assumed a neuronal phenotype. These results demonstrate the existence of drastic differences in the regulation of transgene expression in different types of cell lines, indicating that when studying transgene function in cells that are not growing exponentially, viral promoter-driven expression should not be taken for granted.     

Ferralterin: An iron-sulfur protein functional in enzyme regulation in photosynthesis

The chloroplast new protein factor that was recently shown to link light to the activation of fructose 1,6-bisphosphatase was identified as a previously unrecognized iron-sulfur protein. This protein, given the name “ferralterin,” was purified to homogeneity from spinach leaves and from the blue-green alga (cyanobacterium) Nostoc muscorum. Ferralterin from both sources showed a visible absorption peak at 410nm, a molecular weight of about 30,000 and (provisionally) 4 g-atoms per mole each of nonheme iron and acid labile sulfide. The homogeneous ferralterin preparations catalyzed a light-dependent activation of chloroplast fructose 1,6-bisphosphatase that was dependent only on chlorophyll-containing membranes.     

Metabolic utilization of muscular L-proline in 24-hr starved rats.

1. The aim of this paper was to study the in vivo skeletal muscle L-proline related to its destination to other key tissues such as liver and intestine as well as to give some insight into the role of blood cells in proline handling. 2. L-U-[14C]Proline was injected intramuscularly and following by sampling of blood, liver, intestine and contralateral muscle at 20 and 30 min after injection. 3. The distribution of radioactivity between blood cells and plasma and in total and individual amino acids, protein and glycogen fractions was determined in the above tissues. 4. The pattern of well fed rats was compared with those submitted to 24-hr complete starvation. 5. During starvation a minor degree of proline oxidation occurs. 6. The main destruction of proline in the liver seem to be the synthesis of proteins. 7. The radioactivity recovered in the blood proline fraction of starved rats is twice that of the fed rats and that it could be attributed mainly to plasma protein. 8. We have obtained in vivo evidence for the role of erythrocyte in the interorgan proline transport.     

Human toxicology of BCG applied in cancer immunotherapy

Summary Seventy-five patients were treated for short periods with BCG either per os (7), by aerosols (2), i.d. with needles, i.d. with heaf-gun, on one or four scarification areas, i.v., or intratumorally. Two hundred and seventy-seven were treated for more than 3 years by BCG applied scarifications.The local reactions after application on scarification are negligible, the most frequent being pruritus and adenopathies.The systemic reactions are due to the BCG septicemia which is induced and which has been proved by the search for liver granulomas. Some reactions are of an allergic nature (e.g., choroiditis), but most are direct manifestations of the septicemia (fever, hepatomegaly, splenomegaly). One death was observed after tumoral injection in a terminal patient, otherwise there were no deaths, even in the patients under long-term treatment with the other metabolites.Deterioration of immune reactions may be induced either by the method of BCG application which is followed by a (probably) very small penetration (on scarified area in allergics), or by the penetration of high doses (four scarified areas in anergics and intravenous injections in anergics and in allergics). Reprint requests should be addressed to: G. Mathé, 14-16, avenue Paul-Vaillant-Couturier, F-94800 Villejuif (France)     

A social panorama within the life cycle thinking and the circular economy: a literature review

Purpose

This literature review aims to present the current methodologies that have been developed to perform a social life cycle assessment (sLCA) and to display the main differences among them. In addition to that, to identify the nexus between sLCA and circular economy (CE) and to what extent this life cycle technique has been involved within CE studies.

Methods

An analysis of scientific literature using online databases was made. A total of 76 publications, including all industry sectors worldwide, were chosen spanning 11 years, from 2009 to 2020. Special attention was made to the methodology used to assess the social impacts, the impact categories analyzed, and whether there is or not a circular economy case. All the impact categories of both UNEP/SETAC and PSIA were taken into account when doing the review, and the top three of the categories are mentioned here.

Results and discussion

The leadership of the UNEP/SETAC methodology is clear with 58 cases. Almost 90% of the case studies are focused on products while the remaining ones are related with services. Workers are the most considered stakeholder when conducting an sLCA research, followed by local communities and society. Regarding the impact assessment, the performance reference point (PRP) was the most common method used. When considering the CE even when some cases included the end-of-life stage in the system boundaries, the studies did not consider the actors from that stage; excluding these cases, one out of four articles has a link with CE, a promising proportion taking into account the early stage of both concepts (i.e., sLCA and CE).

Conclusions

UNEP/SETAC guidelines seem to be the most promising methodology due to its reception among the scientific community. However, a more industry-oriented approach is proposed by the Roundtable for Product Social Metrics (PSIA) in a way to respond to manufacturing companies’ demand. Regardless of the type of methodology to be implemented, workers represent the key stakeholder when assessing social impacts. The change in usual patterns is leading to a change in the way how stakeholders interact and therefore new and more impacts may arise, and that is the reason why it is important to include the CE into the sLCA. A series of challenges such as the feasibility of aggregating all the life cycle techniques to one (life cycle sustainability assessment), data availability, and quality are still present for the moment.