Life history adaptation of Tanymastix stagnalis (Crustacea,Branchiopoda) to habitat characteristics

Life histories of two populations of Tanymastix stagnalisfrom sites in central Italy, differing in climate and altitude above sea level, were compared to obtain information on the tolerance limits of this species.Temperature was the main factor affecting the biology of Tanymastix stagnalis. Significant differences in growth patterns occurred at different sites. A colder climate induced delayed hatching, slower differentiation and maturation, but a longer life span in the mountain population (Forca Canapine) than in the plain (Fosso dei Mergani).Both populations exhibited an initial fluctuating sex ratio, which later became female biased, a pattern which could be the consequence of adaptation to the unstable nature of the biotopes studied.     

Enhancement of the Immunostimulatory Functions of Ex Vivo–Generated Dendritic Cells from Early-Stage Colon Cancer Patients by Consecutive Exposure to Low Doses of Sequential-Kinetic-Activated IL-4 and IL-12. A Preliminary Study

Dendritic cells (DCs), specialized antigen-presenting cells bridging innate and adaptive immunity, play a crucial role in determining specific immune response to tumors. Because of their potent immunoregulatory capacities, DCs have been exploited in anticancer vaccination, with limited success thus far. This pilot study compared low-dose interleukin (IL)-4 and IL-12 prepared by sequential kinetic activation (SKA) with standard doses of the same recombinant human cytokines on functional activity of ex vivo–generated monocyte-derived (Mo) DCs from colon carcinoma patients and normal subjects. MoDCs were exposed to medium alone, SKA-IL-4 (0.5 fg/ml), or SKA-IL-12 (2 fg/ml), alone or consecutively combined, in parallel with rhIL-4 (50 ng/ml) and rhIL-12 (1 ng/ml). Primary allogeneic one-way mixed lymphocyte reaction (MLR) was the end point to assess in vitro T-lymphocyte proliferation in response to MoDCs, and secreted IL-12p70 and interferon-γ in MLR supernatants measured by ELISA to assay for T-helper 1–promoting MoDC phenotype. No single agent enhanced the compromised allostimulatory activity of MoDCs from colon cancer patients, unlike healthy donors. However, MoDCs from nonmetastatic colon cancer patients, after sequential exposure to SKA-IL-4 (48 hours) and SKA-IL-12 (24 hours), displayed increased T-cell stimulatory capacity by MLR and acquired driving T-helper 1 polarization activity, although less markedly than the effects induced by recombinant human cytokines or found in normal subjects. These results point to an immunomodulatory capacity of low-dose SKA-IL-4 and SKA-IL-12 and encourage further investigation to provide clues for the rational development of new and more effective immunotherapeutic strategies against cancer.     

Metabolic Syndrome and Breast Cancer Risk: A Case-Cohort Study Nested in a Multicentre Italian Cohort

Background

Metabolic syndrome (defined as at least three among abdominal obesity, high blood triglycerides, low high-density lipoprotein cholesterol, high blood glucose, and high blood pressure) is emerging as a risk factor for breast cancer; however few studies – most confined to postmenopausal women – have investigated associations between breast cancer risk and metabolic syndrome. The purpose of this study was to examine the association between metabolic syndrome and its components, and risk of breast cancer in postmenopausal and premenopausal women.

Methods

We performed a case-cohort study on 22,494 women recruited in 1993-1998 to four Italian centres (Turin, Varese, Naples, Ragusa) of the European Prospective Investigation into Cancer and Nutrition (EPIC) and followed-up for up to 15 years. A random subcohort of 565 women was obtained and 593 breast cancer cases were diagnosed. Hazard ratios (HR) with 95% confidence intervals (CI), adjusted for potential confounders, were estimated by Prentice-weighted Cox proportional hazards models.

Results

Presence of metabolic syndrome was associated with significantly increased breast cancer risk in all women (HR 1.52, 95%CI 1.14-2.02). When the analyses were repeated separately for menopausal status, the association was limited to postmenopausal women (HR 1.80, 95%CI 1.22-2.65) and absent in premenopausal women (HR 0.71, 95%CI 0.43-1.16); P for interaction between metabolic syndrome and menopausal status was 0.001. Of metabolic syndrome components, only high blood glucose was significantly associated with increased breast cancer risk in all women (HR 1.47, 95%CI 1.13-1.91) and postmenopausal women (HR 1.89, 95%CI 1.29-2.77), but not premenopausal women (HR 0.80, 95%CI 0.52-1.22; P interaction=0.004).

Conclusions

These findings support previous data indicating that metabolic syndrome is an important risk factor for breast cancer in postmenopausal women, but not in premenopausal women, and suggest that prevention of metabolic syndrome through lifestyle changes could confer protection against breast cancer.     

Human Neuroserpin: Structure and Time-Dependent Inhibition

Human neuroserpin (hNS) is a protein serine protease inhibitor expressed mainly in the nervous system, where it plays key roles in neural development and plasticity by primarily targeting tissue plasminogen activator (tPA). Four hNS mutations are associated to a form of autosomal dominant dementia, known as familial encephalopathy with neuroserpin inclusion bodies. The medical interest in and the lack of structural information on hNS prompted us to study the crystal structure of native and cleaved hNS, reported here at 3.15 and 1.85 Å resolution, respectively. In the light of the three-dimensional structures, we focus on the hNS reactive centre loop in its intact and cleaved conformations relative to the current serpin polymerization models and discuss the protein sites hosting neurodegenerative mutations. On the basis of homologous serpin structures, we suggest the location of a protein surface site that may stabilize the hNS native (metastable) form. In parallel, we present the results of kinetic studies on hNS inhibition of tPA. Our data analysis stresses the instability of the hNS-tPA complex with a dissociation half-life of minutes compared to a half-life of weeks observed for other serpin-cognate protease complexes.     

Expression of the PsMT A1 gene in white poplar engineered with the MAT system is associated with heavy metal tolerance and protection against 8-hydroxy-2′-deoxyguanosine mediated-DNA damage

Marker-free transgenic white poplar (Populus alba L., cv ‘Villafranca’) plants, expressing the PsMT _A1 gene from Pisum sativum for a metallothionein-like protein, were produced by Agrobacterium tumefaciens-mediated transformation. The 35SCaMV-PsMT _A1 -NosT cassette was inserted into the ipt-type vector pMAT22. The occurrence of the abnormal ipt-shooty phenotype allowed the visual selection of transformants, while the yeast site-specific recombination R/RS system was responsible for the excision of the undesired vector sequences with the consequent recovery of normal marker-free transgenic plants. Molecular analyses confirmed the presence of the 35SCaMV-PsMT _A1 -NosT cassette and transgene expression. Five selected lines were further characterized, revealing the ability to withstand heavy metal toxicity. They survived 0.1 mM CuCl₂, a concentration which strongly affected the nontransgenic plants. Moreover, root development was only slightly affected by the ectopic expression of the transgene. Reactive oxygen species were accumulated to a lower extent in leaf tissues of multi-auto-transformation (MAT)-PsMT_A1 plants exposed to copper and zinc, compared to control plants. Tolerance to photo-oxidative stress induced by paraquat was another distinctive feature of the MAT-PsMT_A1 lines. Finally, low levels of DNA damage were detected by quantifying the amounts of 8-hydroxy-2′-deoxyguanosine in leaf tissues of the transgenic plants exposed to copper.     

SEM morphological observations on Artemiopsis stefanssoni Johansen, 1921 (Crustacea, Anostraca)

The morphology of the female ovisac of the fairy shrimp Artemiopsis stefanssoni Johansen, 1921, is analysed by SEM. SEM observations reveal the existence of a genital opening located ventrally, but anterior to the area where the genital pore is normally situated. Ornamented frontal knobs resembling those on the second antennae of males of Artemia were also found in Artemiopsismales, and account for its particular mating behaviour.     

Ammonium induction of a novel isoform of glucose-6P dehydrogenase in barley roots

The effects of ammonium and glutamine supply on amino acid levels and the activity of glucose-6P dehydrogenase (G6PDH EC 1.1.1.49), the main regulated enzyme of the oxidative pentose phosphate pathway, were investigated in barley roots ( Hordeum vulgare cv. Alfeo). Feeding ammonium to barley plants increased the contents of glutamine, asparagine and G6PDH in roots. These effects were abolished by using inhibitors of glutamine synthetase. Glutamine-fed barley roots showed a similar increase in G6PDH activities to ammonium-fed plants. Two G6PDH enzymes (G6PDH 1 and 2) were partially purified and characterized from ammonium-fed and glutamine-fed roots. The isozymes had different pH optima and apparent Km values for glucose-6P. G6PDH 2 showed similar kinetic parameters to the G6PDH present in root extracts of barley grown without any nitrogen source, while G6PDH 1 exhibited different kinetic parameters, suggesting the appearance of a second G6PDH isoform in response to ammonium. Western blot analysis demonstrated the existence of two G6PDH subunits of different molecular mass in barley roots grown in the presence of ammonium or glutamine, while only one isoform could be detected in roots grown without any nitrogen source. The results suggest a primary role of ammonium and/or glutamine in the appearance of a novel G6PDH isoform; this enzyme (G6PDH 1) shows kinetic parameters similar to those measured previously for chloroplastic and plastidic isoforms and seems to be induced by changes in glutamine content or a related compound(s) in the roots.     

Direct association of Bloom’s syndrome gene product with the human mismatch repair protein MLH1

Bloom’s syndrome (BS) is a rare genetic disorder characterised by genomic instability and cancer susceptibility. BLM, the gene mutated in BS, encodes a member of the RecQ family of DNA helicases. Here, we identify hMLH1, which is involved in mismatch repair (MMR) and recombination, as a protein that directly interacts with BLM both in vivo and in vitro, and that the two proteins co-localise to discrete nuclear foci. The interaction between BLM and hMLH1 appears to have been evolutionarily conserved, as Sgs1p, the Saccharomyces cerevisiae homologue of BLM, interacts with yeast Mlh1p. However, cell extracts derived from BS patients show no obvious defects in MMR compared to wild-type- and BLM-complemented BS cell extracts. We conclude that the hMLH1–BLM interaction is not essential for post-replicative MMR, but, more likely, is required for some aspect of genetic recombination.     

Improving the dialogue between public health and ecosystem science on antimicrobial resistance

The concept of health has evolved markedly from a bio-medical, mechanistic model to include an interdisciplinary perspective where human, animal and ecosystem health are integrated. One Health, EcoHealth and Planetary Health are examples of approaches to health advocating collaboration and interdisciplinarity at multiple levels. In practice, successful integration has been challenging and in particular, understanding of the ecosystem component of health lags behind the human and animal components. Antimicrobial resistance is an important threat to human health, which develops, is maintained and transmitted at the human–animal–environment interface. While the human and livestock components of resistance are well understood, this is not the case for the ecosystem component. This gap in knowledge leads to a poor representation of the environmental dimension of antimicrobial resistance in key policy documents and in interdisciplinary work around this issue. We interviewed a group of leading researchers in public health and ecology to explore their perceptions on the integration of ecosystem and public health research in the context of antimicrobial resistance. Experts from both fields considered that research on antimicrobial resistance is only beginning to consider ecosystems. They highlighted various barriers that have contributed to limited integration, such as conceptual barriers, and a lack of knowledge translators as facilitators. Better interdisciplinary integration is needed to address the challenge of antimicrobial resistance. Improving the dialogues between the disciplines is a necessary first step in this process. Greater engagement of ecologists is needed to build a more complete understanding of the role of ecosystems in human health, and identify how human interactions with ecosystems can both contribute to, and restrict, the development of antimicrobial resistance.