The exposure of outdoor workers to solar ultraviolet radiation (UVR) has been known for some time. Measurements of erythemally weighted UVR are usually related to days of exposure and to the ...anatomical distribution of UVR on the human body. The aim of this research is to describe the UVR exposure of workers during a strawberry production cycle in order to assess the UVR hazard and to identify the highest exposure in the anatomical distribution of UVR on the body during an entire agricultural production cycle. This research was carried out on the experimental farm (Azienda Agraria Didattico-Sperimentale) of Università Politecnica delle Marche in Agugliano, Italy. A spectrometer was used to measure UVR, and electronic dosimeters were used to record UVR exposure. The measurements were carried out on all working days of the strawberry production cycle in 2012 during daily peak UVR levels. The daily UVR exposure geometric mean and the percentage ambient UVR in the strawberry production cycle were calculated and analyzed to assess the hazard for workers during the entire production cycle. The nape of the neck was the anatomical site most exposed to UVR. The mean daily UVR exposure on the nape of the neck was higher than 1.50 SED, the minimum value required to produce perceptible erythema in unacclimatized white skin, and a maximum value of 2.29 SED was measured. Real-time exposure data suggest that it may be useful to remind workers of the risks associated with UVR exposure.
Given the scarcity of donors, moderately fatty livers (FLs) are currently being considered as possible grafts for orthotopic liver transplantation (OLT), notwithstanding their poor tolerance to ...conventional cold preservation. The behaviour of parenchymal and sinusoidal liver cells during transplantation is being studied worldwide. Much less attention has been paid to the biliary tree, although this is considered the Achille's heel even of normal liver transplantation. To evaluate the response of the biliary compartment of FLs to the various phases of OLT reliable markers are necessary. Previously we demonstrated that Alkaline Phosphatase was scarcely active in bile canaliculi of FLs and thus ruled it out as a marker. As an alternative, dipeptidylpeptidase-IV (DPP-IV), was investigated. This ecto-peptidase plays an important role in glucose metabolism, rapidly inactivating insulin secreting hormones (incretins) that are important regulators of glucose metabolism. DPP-IV inhibitors are indeed used to treat Type II diabetes. Neuropeptides regulating bile transport and composition are further important substrates of DPP-IV in the enterohepatic axis. DPP-IV activity was investigated with an azo-coupling method in the liver of fatty Zucker rats (fa/fa), using as controls lean Zucker (fa/+) and normal Wistar rats. Protein expression was studied by immunofluorescence with the monoclonal antibody (clone 5E8). In Wistar rat liver, DPP-IV activity and expression were high in the whole biliary tree, and moderate in sinusoid endothelial cells, in agreement with the literature. Main substrates of DPP-IV in hepatocytes and cholangiocytes could be incretins GLP-1 and GIP, and neuropeptides such as vasoactive intestinal peptide (VIP) and substance P, suggesting that these substances are inactivated or modified through the biliary route. In lean Zucker rat liver the enzyme reaction and protein expression patterns were similar to those of Wistar rat. In obese rat liver the patterns of DPP-IV activity and expression in hepatocytes reflected the morphological alterations induced by steatosis as lipid-rich hepatocytes had scarce activity, located either in deformed bile canaliculi or in the sinusoidal and lateral domains of the plasma membrane. These findings suggest that bile canaliculi in steatotic cells have an impaired capacity to inactivate incretins and neuropeptides. Incretin and/or neuropeptide deregulation is indeed thought to play important roles in obesity and insulin-resistance. No alteration in enzyme activity and expression was found in the upper segments of the biliary tree of obese respect to lean Zucker and Wistar rats. In conclusion, this research demonstrates that DPP-IV is a promising in situ marker of biliary functionality not only of normal but also of fatty rats. The approach, initially devised to investigate the behaviour of the liver during the various phases of transplantation, appears to have a much higher potentiality as it could be further exploited to investigate any pathological or stressful conditions involving the biliary tract (i.e., metabolic syndrome and cholestasis) and the response of the biliary tract to therapy and/or to surgery.
Mangroves create an ecological environment for a diverse assemblage of organisms, including marine and mangrove oomycetes. Halophytophthora spp., in particular, are isolated from fallen senescent ...mangrove leaves. Studies reported on Philippines oomycetes are mostly on their distribution and taxonomy, while fatty acid studies have not yet been fully explored. Recently, oomycetes were reported as efficient producers of various fatty acids; therefore, bioprospecting efforts are aimed at obtaining more industrially important fatty acid compounds for aquaculture, biodiesel production, and human consumption. In this study, 21 isolated oomycetes, identified as Halophytophthora spp., and two type species of Phytopythium, were grown in a broth medium containing peptone, yeast extract, glucose, and 50% seawater and incubated at room temperature for 3 weeks for fatty acid production and identification. Results revealed the presence of various fatty acids, mainly palmitic acid (C16:0), linoleic acid (C18:2n6c), oleic acid (C18:1n9c), cis-11,14,17-eicosatrienoic acid (ETA, C20:3n3), and stearic acid (C18:0), from Halophytophthora and Phytopythium isolates ranging from 2% to 30% total fatty acids. An omega-6 fatty acid, Ƴ-linolenic acid (GLA, C18:3n6), was found in Phytopythium isolates with considerably higher concentrations compared to Halophytophthoras. Further, omega-3 polyunsaturated fatty acid, cis-11,14,17-eicosatrienoic acid (ETA, C20:3n3), was detected on most oomycete isolates.
Antibody phage technology has greatly facilitated the isolation of good-quality monoclonal antibodies to virtually any target antigen. Large combinatorial phage display libraries of human antibodies ...are routinely being used for the identification of antibody candidates for clinical applications. However, preclinical studies in rodents would benefit from the availability of good-quality single-pot mouse antibody libraries, which at present are not available. In this article, we report on the construction of three mouse antibody phage display libraries, all containing over 1
billion antibody clones and all based on a similar library design, which featured the combinatorial mutagenesis of residues in the CDR3 loops of a given antibody scaffold. While all three libraries were found to express antibodies in bacterial supernatants, only one of them (termed “PHILOtop”) was shown to reliably yield good-quality antibodies towards all protein antigens used so far in selection experiments, including three tumor-associated antigens. The modular structure of the PHILOtop library facilitates a simple affinity-maturation procedure based on the combinatorial mutagenesis of CDR1 and CDR2 loops of the VH domain, which has led to the isolation of a high-affinity antibody (“H7”; Kd
=
6
nM) specific to the EDB domain of fibronectin, a marker of angiogenesis. The single-pot antibody library PHILOtop may thus represent a useful source of binding specificities, facilitating preclinical studies in immunocompetent syngeneic mouse models of pathology.
Antibody–drug conjugates (ADCs) represent a promising class of biopharmaceuticals with the potential to localize at the tumor site and improve the therapeutic index of cytotoxic drugs. While it is ...generally believed that ADCs need to be internalized into tumor cells in order to display optimal therapeutic activity, it has recently been shown that non‐internalizing antibodies can efficiently liberate disulfide‐linked drugs at the extracellular tumor site, leading to potent anti‐cancer activity in preclinical animal models. Here, we show that engineered variants of the F16 antibody, specific to a splice isoform of tenascin‐C, selectively localize to the subendothelial tumor extracellular matrix in three mouse models of human cancer (U87, A431, MDA‐MB‐231). A site‐specific coupling of F16 in IgG format with a monomethyl auristatin E (MMAE) derivative, featuring a valine‐citrulline dipeptide linker equipped with a self‐immolative spacer, yielded an ADC product, which cured tumor‐bearing mice at a dose of 7 mg/Kg. The observation of an efficient extracellular proteolytic cleavage of the valine‐citrulline linker was surprising, as it has generally been assumed that this peptidic structure would be selectively cleaved by cathepsin B in intracellular compartments. The products described in this article may be useful for the treatment of human malignancies, as their cognate antigen is strongly expressed in the majority of human solid tumors, lymphomas and aggressive leukemias, while being virtually undetectable in most normal adult tissues.
What's new?
Antibody–drug conjugates consist of a tumor‐seeking antibody, a payload (cytotoxic agent), and a linker connecting the two. Following internalization by targeted cancer cells, the components separate, with cell uptake considered essential for optimal therapeutic activity. This study shows, however, that non‐internalizing antibody–drug conjugates, equipped with peptide‐based linker‐payload combinations, can efficiently release cytotoxic drugs in the tumor stroma, with potent therapeutic activity in mouse models of human cancer. The study may be of clinical relevance, as it used a clinical‐stage antibody (F16) and the linker‐payload combination of an approved biopharmaceutical (brentuximab vedotin).
The extracellular matrix protein ED-B fibronectin (ED-B) is upregulated in inflammatory atherosclerotic lesions. However, functional in vivo imaging of ED-B-containing plaques has not been explored. ...This study evaluated whether (99m)Tc-conjugated AP39 ((99m)Tc-AP39), a single-chain antibody specific to ED-B, can be used for in vivo detection of atherosclerotic plaques in Western diet (WD)-fed, apolipoprotein E-deficient (apoE-/-) mice as compared to wildtype (WT) control mice.
Using SPECT, 12-month-old WD-fed apoE-/- and WT mice were studied 4 hours after injecting (99m)Tc-AP39 (148 MBq). Subsequently, mice were sacrificed, thoracic aortas measured in a g-counter, and plaques analyzed using histology, immuno-histochemistry, autoradiography, and morphometry.
In vivo (99m)Tc-AP39-SPECT imaging of apoE-/- mice demonstrated a significant signal activity in the plaque-ridden thoracic aorta (52.236 ± 40.646 cpm/cm³) that co-localized with the aortic arch and the supra-aortic arteries in MRI scans. Low signal activity (9.468 ± 4.976 cpm/cm³) was observed in WT mice. In apoE-/- mice, the strongest signals were detected in the aortic root, aortic arch and along the abdominal aorta. Autoradiography analysis of aortas from apoE-/- mice confirmed the in vivo observation by demonstrating signal localization in atherosclerotic plaques. The size of autoradiography-positive plaque areas correlated significantly with the size of ED-B-positive (r=0.645, P=0.044) or macrophage-infiltrated (r=0.84, P<0.002) plaques. A significant correlation was found between the sizes of ED-B-positive and macrophage-infiltrated plaque areas (r=0.93, P<0.01).
(99m)Tc-AP39-SPECT in vivo imaging detects inflammatory plaque lesions in WD-fed apoE-/- mice.
Magnetic particles as matrix for enzyme immobilization have been used and due to the enzymatic derivative can be easily removed from the reaction mixture by a magnetic field. This work presents a ...study about the synthesis and characterization of iron phases into magnetic montmorillonite clay (mMMT) and magnetic diatomaceous earth (mDE) by
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Fe Mössbauer spectroscopy (MS), magnetic measurements and X-ray diffraction (XRD). Also these magnetic materials were assessed as matrices for the immobilization of invertase via covalent binding. Mössbauer spectra of the magnetic composites performed at 4.2 K showed a mixture of magnetite and maghemite about equal proportion in the mMMT, and a pure magnetite phase in the sample mDE. These results were verified using XRD. The residual specific activity of the immobilized invertase on mMMT and mDE were 83 % and 92.5 %, respectively. Thus, both magnetic composites showed to be promising matrices for covalent immobilization of invertase.
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