Specific nanoprobe design for MRI: Targeting laminin in the blood-brain barrier to follow alteration due to neuroinflammation

Chronic neuroinflammation is characterized by increased blood-brain barrier (BBB) permeability, leading to molecular changes in the central nervous system that can be explored with biomarkers of active neuroinflammatory processes. Magnetic resonance imaging (MRI) has contributed to detecting lesions and permeability of the BBB. Ultra-small superparamagnetic particles of iron oxide (USPIO) are used as contrast agents to improve MRI observations. Therefore, we validate the interaction of peptide-88 with laminin, vectorized on USPIO, to explore BBB molecular alterations occurring during neuroinflammation as a potential tool for use in MRI. The specific labeling of NPS-P88 was verified in endothelial cells (hCMEC/D3) and astrocytes (T98G) under inflammation induced by interleukin 1β (IL-1β) for 3 and 24 hours. IL-1β for 3 hours in hCMEC/D3 cells increased their co-localization with NPS-P88, compared with controls. At 24 hours, no significant differences were observed between groups. In T98G cells, NPS-P88 showed similar nonspecific labeling among treatments. These results indicate that NPS-P88 has a higher affinity towards brain endothelial cells than astrocytes under inflammation. This affinity decreases over time with reduced laminin expression. In vivo results suggest that following a 30-minute post-injection, there is an increased presence of NPS-P88 in the blood and brain, diminishing over time. Lastly, EAE animals displayed a significant accumulation of NPS-P88 in MRI, primarily in the cortex, attributed to inflammation and disruption of the BBB. Altogether, these results revealed NPS-P88 as a biomarker to evaluate changes in the BBB due to neuroinflammation by MRI in biological models targeting laminin.

Cortical matrix remodeling as a hallmark of relapsing-remitting neuroinflammation in MR elastography and quantitative MRI

Multiple sclerosis (MS) is a chronic neuroinflammatory disease that involves both white and gray matter. Although gray matter damage is a major contributor to disability in MS patients, conventional clinical magnetic resonance imaging (MRI) fails to accurately detect gray matter pathology and establish a clear correlation with clinical symptoms. Using magnetic resonance elastography (MRE), we previously reported global brain softening in MS and experimental autoimmune encephalomyelitis (EAE). However, it needs to be established if changes of the spatiotemporal patterns of brain tissue mechanics constitute a marker of neuroinflammation. Here, we use advanced multifrequency MRE with tomoelastography postprocessing to investigate longitudinal and regional inflammation-induced tissue changes in EAE and in a small group of MS patients. Surprisingly, we found reversible softening in synchrony with the EAE disease course predominantly in the cortex of the mouse brain. This cortical softening was associated neither with a shift of tissue water compartments as quantified by T2-mapping and diffusion-weighted MRI, nor with leukocyte infiltration as seen by histopathology. Instead, cortical softening correlated with transient structural remodeling of perineuronal nets (PNNs), which involved abnormal chondroitin sulfate expression and microgliosis. These mechanisms also appear to be critical in humans with MS, where tomoelastography for the first time demonstrated marked cortical softening. Taken together, our study shows that neuroinflammation (i) critically affects the integrity of PNNs in cortical brain tissue, in a reversible process that correlates with disease disability in EAE, (ii) reduces the mechanical integrity of brain tissue rather than leading to water accumulation, and (iii) shows similar spatial patterns in humans and mice. These results raise the prospect of leveraging MRE and quantitative MRI for MS staging and monitoring treatment in affected patients.

Amino acids L-phenylalanine and L-lysine involvement in trans and cis piperamides biosynthesis in two Piper species

Several Piper species accumulate piperamides as secondary metabolites, and although they have relevant biological importance, many details of their biosynthetic pathways have not yet been described experimentally. Experiments involving enzymatic reactions and labeled precursor feeding were performed using the species Piper tuberculatum and Piper arboreum. The activities of the phenylalanine ammonia lyase (PAL) enzymes, which are involved in the general phenylpropanoid pathway, were monitored by the conversion of the amino acid L-phenylalanine to cinnamic acid. The activity of the 4-hydroxylase (C4H) enzyme was also observed in P. tuberculatum by converting cinnamic acid to p-coumaric acid. L-[UL-14C]-phenylalanine was fed into the leaves of P. tuberculatum and incorporated into piperine (1), 4,5-dihydropiperine (2), fagaramide (4), trans-piplartine (7), and dihydropiplartine (9). In P. arboreum, it was only incorporated into the piperamide 4,5-dihydropiperiline (3). L-[UL-14C]-lysine was successfully incorporated into the 4,5-dihydropiperine piperidine group (2), dihydropyridinone, and trans- (7) and cis-piplartine (8). These data corroborate the proposal of mixed biosynthetic origin of piperamides with the aromatic moiety originating from cinnamic acid (shikimic acid pathway) and key amide construction with amino acids as precursors.

Different Impact of Gadopentetate and Gadobutrol on Inflammation-Promoted Retention and Toxicity of Gadolinium Within the Mouse Brain

OBJECTIVES

Using a murine model of multiple sclerosis, we previously showed that repeated administration of gadopentetate dimeglumine led to retention of gadolinium (Gd) within cerebellar structures and that this process was enhanced with inflammation. This study aimed to compare the kinetics and retention profiles of Gd in inflamed and healthy brains after application of the macrocyclic Gd-based contrast agent (GBCA) gadobutrol or the linear GBCA gadopentetate. Moreover, potential Gd-induced neurotoxicity was investigated in living hippocampal slices ex vivo.

MATERIALS AND METHODS

Mice at peak of experimental autoimmune encephalomyelitis (EAE; n = 29) and healthy control mice (HC; n = 24) were exposed to a cumulative dose of 20 mmol/kg bodyweight of either gadopentetate dimeglumine or gadobutrol (8 injections of 2.5 mmol/kg over 10 days). Magnetic resonance imaging (7 T) was performed at baseline as well as at day 1, 10, and 40 post final injection (pfi) of GBCAs. Mice were sacrificed after magnetic resonance imaging and brain and blood Gd content was assessed by laser ablation-inductively coupled plasma (ICP)-mass spectrometry (MS) and ICP-MS, respectively. In addition, using chronic organotypic hippocampal slice cultures, Gd-induced neurotoxicity was addressed in living brain tissue ex vivo, both under control or inflammatory (tumor necrosis factor α [TNF-α] at 50 ng/μL) conditions.

RESULTS

Neuroinflammation promoted a significant decrease in T1 relaxation times after multiple injections of both GBCAs as shown by quantitative T1 mapping of EAE brains compared with HC. This corresponded to higher Gd retention within the EAE brains at 1, 10, and 40 days pfi as determined by laser ablation-ICP-MS. In inflamed cerebellum, in particular in the deep cerebellar nuclei (CN), elevated Gd retention was observed until day 40 after last gadopentetate application (CN: EAE vs HC, 55.06 ± 0.16 μM vs 30.44 ± 4.43 μM). In contrast, gadobutrol application led to a rather diffuse Gd content in the inflamed brains, which strongly diminished until day 40 (CN: EAE vs HC, 0.38 ± 0.08 μM vs 0.17 ± 0.03 μM). The analysis of cytotoxic effects of both GBCAs using living brain tissue revealed an elevated cell death rate after incubation with gadopentetate but not gadobutrol at 50 mM. The cytotoxic effect due to gadopentetate increased in the presence of the inflammatory mediator TNF-α (with vs without TNF-α, 3.15% ± 1.18% vs 2.17% ± 1.14%; P = 0.0345).

CONCLUSIONS

In the EAE model, neuroinflammation promoted increased Gd retention in the brain for both GBCAs. Whereas in the inflamed brains, efficient clearance of macrocyclic gadobutrol during the investigated time period was observed, the Gd retention after application of linear gadopentetate persisted over the entire observational period. Gadopentetate but not gadubutrol appeared to be neurotoxic in an ex vivo paradigm of neuronal inflammation.

Fibrin-targeting molecular MRI in inflammatory CNS disorders

BACKGROUND

Fibrin deposition is a fundamental pathophysiological event in the inflammatory component of various CNS disorders, such as multiple sclerosis (MS) and Alzheimer's disease. Beyond its traditional role in coagulation, fibrin elicits immunoinflammatory changes with oxidative stress response and activation of CNS-resident/peripheral immune cells contributing to CNS injury.

PURPOSE

To investigate if CNS fibrin deposition can be determined using molecular MRI, and to assess its capacity as a non-invasive imaging biomarker that corresponds to inflammatory response and barrier impairment.

MATERIALS AND METHODS

Specificity and efficacy of a peptide-conjugated Gd-based molecular MRI probe (EP2104-R) to visualise and quantify CNS fibrin deposition were evaluated. Probe efficacy to specifically target CNS fibrin deposition in murine adoptive-transfer experimental autoimmune encephalomyelitis (EAE), a pre-clinical model for MS (n = 12), was assessed. Findings were validated using immunohistochemistry and laser ablation inductively coupled plasma mass spectrometry. Deposition of fibrin in neuroinflammatory conditions was investigated and its diagnostic capacity for disease staging and monitoring as well as quantification of immunoinflammatory response was determined. Results were compared using t-tests (two groups) or one-way ANOVA with multiple comparisons test. Linear regression was used to model the relationship between variables.

RESULTS

For the first time (to our knowledge), CNS fibrin deposition was visualised and quantified in vivo using molecular imaging. Signal enhancement was apparent in EAE lesions even 12-h after administration of EP2104-R due to targeted binding (M ± SD, 1.07 ± 0.10 (baseline) vs. 0.73 ± 0.09 (EP2104-R), p = .008), which could be inhibited with an MRI-silent analogue (M ± SD, 0.60 ± 0.14 (EP2104-R) vs. 0.96 ± 0.13 (EP2104-La), p = .006). CNS fibrin deposition corresponded to immunoinflammatory activity (R2 = 0.85, p < .001) and disability (R2 = 0.81, p < .001) in a model for MS, which suggests a clinical role for staging and monitoring. Additionally, EP2104-R showed substantially higher SNR (M ± SD, 6.6 ± 1 (EP2104-R) vs. 2.7 ± 0.4 (gadobutrol), p = .004) than clinically used contrast media, which increases sensitivity for lesion detection.

CONCLUSIONS

Molecular imaging of CNS fibrin deposition provides an imaging biomarker for inflammatory CNS pathology, which corresponds to pathophysiological ECM remodelling and disease activity, and yields high signal-to-noise ratio, which can improve diagnostic neuroimaging across several neurological diseases with variable degrees of barrier impairment.

Long-Chain Omega-3 Fatty Acids Supplementation Accelerates Nerve Regeneration and Prevents Neuropathic Pain Behavior in Mice

Fish oil (FO) is the main source of long chain omega-3 polyunsaturated fatty acids (ω-3 PUFAs), which display relevant analgesic and anti-inflammatory properties. Peripheral nerve injury is driven by degeneration, neuroinflammation, and neuronal plasticity which results in neuropathic pain (NP) symptoms such as allodynia and hyperalgesia. We tested the preventive effect of an EPA/DHA-concentrate fish oil (CFO) on NP development and regenerative features. Swiss mice received daily oral treatment with CFO 4.6 or 2.3 g/kg for 10 days after NP was induced by partial sciatic nerve ligation. Mechanical allodynia and thermal hypernociception were assessed 5 days after injury. CFO 2.3 g/kg significantly prevented mechanical and thermal sensitization, reduced TNF levels in the spinal cord, sciatic MPO activity, and ATF-3 expression on DRG cells. CFO improved Sciatic Functional Index (SFI) as well as electrophysiological recordings, corroborating the increased GAP43 expression and total number of myelinated fibers observed in sciatic nerve. No locomotor activity impairment was observed in CFO treated groups. These results point to the regenerative and possibly protective properties of a combined EPA and DHA oral administration after peripheral nerve injury, as well as its anti-neuroinflammatory activity, evidencing ω-3 PUFAs promising therapeutic outcomes for NP treatment.

Use of municipal solid waste incineration bottom ashes in alkali-activated materials, ceramics and granular applications: A review

This paper presents a literature review on the incorporation of municipal solid waste incinerated bottom ash as raw material in several markets, other than those where it is conventionally used, such as geotechnical applications and road pavement construction. The main findings of an ample selection of experimental investigations on the use of the bottom ash as precursor of alkali-activated materials, as an adsorbent material for the removal of hazardous elements from wastewater and landfill gases, as soil replacement in agricultural activities, as partial or complete substitute of raw materials for the manufacture of ceramic-based products, as landfill cover and as biogas production enhancer, were gathered, collated and analysed.

LASSBio-1135: a dual TRPV1 antagonist and anti-TNF-alpha compound orally effective in models of inflammatory and neuropathic pain

LASSBio-1135 is an imidazo[1,2-a]pyridine derivative with high efficacy in screening models of nociception and inflammation, presumed as a weak COX-2 inhibitor. In order to tease out its mechanism of action, we investigated others possible target for LASSBio-1135, such as TNF-α and TRPV1, to better characterize it as a multitarget compound useful in the treatment of chronic pain. TRPV1 modulation was assessed in TRPV1-expressing Xenopus oocytes against capsaicin and low pH-induced current. Modulation of TNF-α production was evaluated in culture of macrophages stimulated with LPS. In vivo efficacy of LASSBio-1135 was investigated in carrageenan and partial sciatic ligation-induced thermal hyperalgesia and mechanical allodynia. Corroborating its previous demonstration of efficacy in a model of capsaicin-induced hyperalgesia, LASSBio-1135 blocks capsaicin-elicited currents in a non-competitive way with an IC₅₀ of 580 nM as well as low pH-induced current at 50 µM. As an additional action, LASSBio-1135 inhibited TNF-α release in these cells stimulated by LPS with an IC₅₀ of 546 nM by reducing p38 MAPK phosphorilation. Oral administration of 100 µmol.Kg⁻¹ LASSBio-1135 markedly reduced thermal hyperalgesia induced by carrageenan, however at 10 µmol.Kg⁻¹ only a partial reduction was observed at the 4^th h. Neutrophil recruitment and TNF-α production after carrageenan stimulus was also inhibited by the treatment with LASSBio-1135. Modulating TRPV1 and TNF-α production, two key therapeutic targets of neuropathic pain, 100 µmol.Kg⁻¹ LASSBio-1135 was orally efficacious in reversing thermal hyperalgesia and mechanical allodynia produced by partial sciatic ligation 7–11 days after surgery without provoking hyperthermia, a common side effect of TRPV1 antagonists. In conclusion LASSBio-1135, besides being a weak COX-2 inhibitor, is a non-competitive TRPV1 antagonist and a TNF-α inhibitor. As a multitarget compound, LASSBio-1135 is orally efficacious in a model of neuropathic pain without presenting hyperthermia.

KPC-2 producing Klebsiella pneumoniae and Escherichia coli co-infection in a catheter-related infection

We describe the first report of simultaneous blood infection with KPC-2 producing Klebsiella pneumoniae and Escherichia coli in a Brazilian patient. We highlight the importance of implementing efficient infection control measures to limit the spread of these phenotypes in a hospital setting.

Variability of Meloidogyne exigua on Coffee in the Zona da Mata of Minas Gerais State, Brazil

Minas Gerais is the major coffee-producing state of Brazil, with 28% of its production coming from the region of Zona da Mata. Four major species of root-knot nematode attacking coffee (Meloidogyne incognita, M. paranaensis, M. coffeicola, and M. exigua) have been reported from Brazil. To determine the variability in Meloidogyne spp. occurring in that region, 57 populations from 20 localities were evaluated for morphological, enzymatic, and physiological characteristics. According to the perineal pattern, all the populations were identified as M. exigua; however populations from the municipality of São João do Manhuaçu exhibited patterns very similar to M. arenaria. The identity of all the populations was confirmed by the phenotypes of esterase, malate dehydrogenase, superoxide dismutase, and glutamate-oxaloacetate transaminase. Thirteen populations (22.8%) showed the typical one-band (E1) esterase phenotype, whereas the others (77.2%) had a novel two-band phenotype (E2). No intraspecies variability was found in any population. All populations were able to reproduce on tomato, pepper, beans, cacao, and soybean. Reproduction was greater on tomato and pepper than on coffee seedlings, the susceptible standard.

The use of hydroxyapatite and autogenous cancellous bone grafts to repair bone defects in rats

Bone grafts are frequently used in the treatment of bone defects. Bone harvesting can cause postoperative complications and sometimes does not provide a sufficient quantity of bone. Therefore, synthetic biomaterials have been investigated as an alternative to autogenous bone grafts. The objective of this study was to evaluate the repair of bone defects by autogenous cancellous bone grafts or porous bioceramic discs of hydroxyapatite/phosphate cement mixture. Two 5-mm diameter defects were made in the skulls of rats and filled with the bioceramic material or cancellous bone. The rats were sacrificed 2, 4, 8 and 24 weeks after surgery and tissue samples were analyzed by radiography and histology. By the 24th week, the defects filled with autogenous cancellous bone grafts or bioceramic material showed similar volumes of bone tissue within the defect. However, defects treated with bioceramic material were almost completely closed as a result of the joining of ceramic fragments and the neoformed bone tissue, while those filled with autogenous grafts showed several areas filled with connective tissue. These results indicated that the osteointegration of bioceramic fragments allowed the reconstruction of parietal bone defects without the need for a bone graft.

[Nursing care for women during climacteric]

Climateric is a transitory stage in women's life, which causes remarkable alterations. This article brings into focus how important the nurse performance is, giving protection, promotion and recuperation for women's health. The authors suggest some recommendations during nursing care.