How the COVID-19 pandemic affected bone health: a retrospective, longitudinal study on denosumab persistence from the epicentre of European spreading.

In this study, we investigated how the COVID-19 pandemic involved osteoporosis care in patients treated with denosumab. Almost a third of patients missed the prescription renewal, mandatory to obtain the subsidized drug. Among patients who suspended denosumab, more than half reported fragility fractures. PURPOSE: This study aimed to evaluate persistence on denosumab (Dmab) treatment during the COVID-19 pandemic and the clinical effects of possible discontinuation. METHODS: We retrospectively assessed patients affected by osteoporosis and treated with Dmab, scheduled to have the yearly renewal of prescription between March 9, 2020, and May 9, 2021, 2 months after the second pandemic wave. In June 2022, a telephone survey started, by calling all patients who missed the yearly renewal of Dmab. Predictors of missed renewal and fragility fracture occurrence were assessed by logistic analyses. RESULTS: Patients scheduled to have a renewal of Dmab prescription during the observational period were 538 (age 75.5 ± 9.3 years, female 511). A total of 152 (28.2%) patients did not have the renewal. Patients not renewing Dmab prescription were significantly older (p = 0.01) and more frequently affected by pulmonary (p = 0.04) and cardiovascular comorbidity (p = 0.01). Telephone survey on non-persistent patients showed that 44 had died, 28 patients were missing, 23 shifted to bisphosphonate treatment, and 22 patients suspended Dmab. Following discontinuation, 12/22 patients (54.5%) reported fragility fractures; 5/22 had multiple fractures, for a total number of 18 fractures, mainly vertebral. Logistic analyses showed that the odds of Dmab withdrawal increased in older patients with pulmonary comorbidity and treated for a shorter time. Dmab discontinuation was the only variable that increased the risk of fracture. CONCLUSION: This study provided real-world data about an impaired persistence of Dmab treatment resulting in an increased number of fragility fractures in a geographic area heavily affected by the outbreak of COVID-19.

The PERCIVAL detector: first user experiments.

The PERCIVAL detector is a CMOS imager designed for the soft X-ray regime at photon sources. Although still in its final development phase, it has recently seen its first user experiments: ptychography at a free-electron laser, holographic imaging at a storage ring and preliminary tests on X-ray photon correlation spectroscopy. The detector performed remarkably well in terms of spatial resolution achievable in the sample plane, owing to its small pixel size, large active area and very large dynamic range; but also in terms of its frame rate, which is significantly faster than traditional CCDs. In particular, it is the combination of these features which makes PERCIVAL an attractive option for soft X-ray science.

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.

Improving water management in European catfish recirculating aquaculture systems through catfish-lettuce aquaponics.

In the context of climate change and population growth, aquaculture plays an important role for food security, employment and economic development. Intensive recirculating aquaculture systems (RAS) allow to treat and recycle fish effluents to reduce waste concentration in outflow water thereby reducing environmental contamination. RAS sustainability may be further improved using aquaponics, a circular productive system in which RAS wastewater is recovered for crop cultivation and recycled back to the fish tanks. In this study, water metabolism of a catfish RAS was assessed and the opportunity to produce lettuce with the RAS effluent was tested. Crop growth and water consumption in aquaponics were compared to those experienced in hydroponics at three nutrient solution concentration (EC of 1.6, 2.0 and 3.0 dS∙m-1), also considering water- (WUE) and nitrogen- use efficiency (NUE). A scenario for converting the RAS in a catfish-lettuce aquaponic system was, then, proposed. The RAS water balance included an input of 555 L∙day-1, out of which 32 L∙day-1 were lost by evaporation from the tubs whereas 460 L∙day-1 were discarded. The lettuce yield, NUE and WUE in aquaponics were respectively 20.3%, 22.3% and 20.6% lower than those obtained in hydroponics. Best performances in hydroponics were achieved with EC of 2.0 dS m-1. No difference in term of water consumption arose between the treatments, with average water use of 46 mL∙plant-1∙day-1. Considering the current RAS productivity of 329 kg year-1, a 10 m2 raft system hosting 160 lettuces would satisfy the nitrogen filtration demand. Once closed the water loop between the two productive sub-units, the current water input of 532 L∙day-1 could be reduced to the amount needed to replace the water lost by evaporation (50 L∙day-1) and the RAS water output would decrease from 555 to 103 L∙day-1.

Characterization of magnetic nanoparticles from Magnetospirillum Gryphiswaldense as potential theranostics tools.

We investigated the theranostic properties of magnetosomes (MNs) extracted from magnetotactic bacteria, promising for nanomedicine applications. Besides a physico-chemical characterization, their potentiality as mediators for magnetic fluid hyperthermia and contrast agents for magnetic resonance imaging, both in vitro and in vivo, are here singled out. The MNs, constituted by magnetite nanocrystals arranged in chains, show a superparamagnetic behaviour and a clear evidence of Verwey transition, as signature of magnetite presence. The phospholipid membrane provides a good protection against oxidation and the MNs oxidation state is stable over months. Using an alternate magnetic field, the specific absorption rate was measured, resulting among the highest reported in literature. The MRI contrast efficiency was evaluated by means of the acquisition of complete NMRD profiles. The transverse relaxivity resulted as high as the one of a former commercial contrast agent. The MNs were inoculated into an animal model of tumour and their presence was detected by magnetic resonance images two weeks after the injection in the tumour mass.

Atomic force microscopy imaging of lipid rafts of human breast cancer cells.

Several studies suggest that the plasma membrane is composed of micro-domains of saturated lipids that segregate together to form lipid rafts. Lipid rafts have been operationally defined as cholesterol- and sphingolipid-enriched membrane micro-domains resistant to solubilization by non-ionic detergents at low temperatures. Here we report a biophysical approach aimed at investigating lipid rafts of MDA-MB-231 human breast cancer cells by coupling an atomic force microscopy (AFM) study to biochemical assays namely Western blotting and high performance thin layer chromatography. Lipid rafts were purified by ultracentrifugation on discontinuous sucrose gradient using extraction with Triton X-100. Biochemical analyses proved that the fractions isolated at the 5% and 30% sucrose interface (fractions 5 and 6) have a higher content of cholesterol, sphingomyelin and flotillin-1 with respect to the other purified fractions. Tapping mode AFM imaging of fraction 5 showed membrane patches whose height corresponds to the one awaited for a single lipid bilayer as well as the presence of micro-domains with lateral dimensions in the order of a few hundreds of nanometers. In addition, an AFM study using specific antibodies suggests the presence, in these micro-domains, of a characteristic marker of lipid rafts, the protein flotillin-1.

Comparison of times of intervention during pediatric CPR maneuvers using ABC and CAB sequences: a randomized trial.

BACKGROUND: The proposed introduction of the CAB (circulation, airway, breathing) sequence for cardiopulmonary resuscitation has raised some perplexity within the pediatric community. We designed a randomized trial intended to verify if and how much timing of intervention in pediatric cardiopulmonary resuscitation is affected by the use of the CAB vs. the ABC (airway, breathing, circulation) sequence. PATIENTS AND METHODS: 340 volunteers, paired into 170 two-person teams, performed 2-rescuer healthcare provider BLS with both a CAB and ABC sequence. Their performances were audio-video recorded and times of intervention in the two scenarios, cardiac and respiratory arrest, were monitored. RESULTS: The CAB sequence compared to ABC prompts quicker recognition of respiratory (CAB vs. ABC=17.48 ± 2.19 vs. 19.17 ± 2.38s; p<0.05) or cardiac arrest (CAB vs. ABC=17.48 ± 2.19 vs. 41.67 ± 4.95; p<0.05) and faster start of ventilatory maneuvers (CAB vs. ABC=19.13 ± 1.47s vs. 22.66 ± 3.07; p<0.05) or chest compressions (CAB vs. ABC=19.27 ± 2.64 vs. 43.40 ± 5.036; p<0.05). CONCLUSIONS: Compared to ABC the CAB sequence prompts shorter time of intervention both in diagnosing respiratory or cardiac arrest and in starting ventilation or chest compression. However, this does not necessarily entail prompter resumption of spontaneous circulation and significant reduction of neurological sequelae, an issue that requires further studies.

Personalization of radioiodine treatment for Graves' disease: a prospective, randomized study with a novel method for calculating the optimal 131I-iodide activity based on target reduction of thyroid mass.

AIM: There is no consensus regarding the most appropriate dosimetric approach to cure Graves' disease. This study describes a personalized approach based on the desired therapy-induced volume (mass) reduction in order to define the activity of 131I-iodide to be administered, based on the MIRD approach and the radiobiological Linear Quadratic Model. METHODS: A model for calculating the "optimal" final thyroid mass has been developed and published in the past years. Based on this model, it is possible to predict the thyroid absorbed dose following administration of a certain activity as a function of desired reduction of the starting mass of the gland. A total of 147 Graves' disease patients were randomly divided into four groups based on the absorbed thyroid dose, respectively 100 Gy (Group A, N.=29), 200 Gy (Group B, N.=25), and 400 Gy (Group C, N.=29), while patients of Group D (n=64) received a 131I-iodide activity calculated based on the desired "optimal" final thyroid mass. RESULTS: At one-year follow-up, 48% of patients in Group A, 64% in Group B, 97% in Group C, and 94% in Group D were cured. There was no statistical difference between cure rate in Group C versus Group D. The administered 131I-iodide activity for Group C was significantly higher than for Group D (524 ± 201 MBq versus 386 ± 173 MBq, P<0.001). CONCLUSION: These results demonstrate that the proposed method allows to optimize 131I-iodide therapy for Graves' disease patients on an individual basis, avoiding the administration of unjustified higher activities.

Aminophosphonic acids and derivatives. Synthesis and biological applications.

In recent years, phosphonic acids and their derivatives have received increasing attention as analogues of a series of naturally occurring phosphates and as "bio-isosteric phosphorus analogues" of amino acids. Unlike a phosphate group, the phosphonate moiety is not readily hydrolyzed, in a biological environment, by the enzymes involved in the phosphate cleavage. This feature makes these compounds extremely useful in several applications, in metabolic regulation, in enhancement or inhibition studies, in the development of potential drugs against several metabolic disorders. The great potential of these compounds in biological applications resulted in an intense effort directed to the development of efficient synthetic methods for their preparation, with particular attention to stereoselective synthesis. The purpose of this review is to give an up-to-date account of the chemistry, the synthesis and the biological activity of aminophosphonic acids and their derivatives.

Semen controlled-release capsules allow a single artificial insemination in sows.

Controlled-release capsules containing boar spermatozoa were developed to extend the preservation time of spermatozoa and maximize the efficiency of a single artificial insemination. A large trial (4245 sows) was performed with these capsules using double/triple conventional artificial insemination as a control. The effect of treatment on pregnancy diagnosis, delivery, and born piglets was investigated, with allowance being made for considering season, spermatozoa amount, and the weaning-to-estrus interval as confounding variables. The same pregnancy rate and prolificacy were obtained by two insemination techniques, and a higher parturition frequency was reached with capsules. The reproductive performance in pigs has therefore been optimized by a single instrumental insemination with controlled-release capsules.

Synthesis and characterization of polyethylenimine-based iron oxide composites as novel contrast agents for MRI.

OBJECT: Use of polyethylenimines (PEIs) of different molecular weight and selected carboxylated-PEI derivatives (PEI-COOH) in the synthesis and stabilization of iron oxide nanoparticles, to obtain possible multifunctional contrast agents. MATERIALS AND METHODS: Oxidation of Fe(II) at slightly elevated pH and temperature resulted in the formation of highly soluble and stable nanocomposites of iron oxides and polymer. Composites were characterized and studied by atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray diffractometry, AC and DC magnetometry, NMR relaxometry and magnetic resonance imaging (MRI). RESULTS: From AFM the dimensions of the aggregates were found to be in the ~150-250 nm size region; the mean diameter of the magnetic core of the compounds named PEI-25, PEI-500 and PEI-COOH60 resulted d approximately 20 +/- 5 nm for PEI-25, d approximately 9.5 +/- 1.0 nm for PEI-500 and d approximately 6.8 +/- 1.0 nm for PEI-COOH60. In PEI-COOH60 TEM and X-ray diffractometry revealed small assemblies of mineral magnetic cores with clear indications that the main constituents are maghemite and/or magnetite as confirmed by AC and DC SQUID magnetometry. For PEI-COOH60, the study of NMR-dispersion profiles revealed r (1) and r (2) relaxivities comparable to superparamagnetic iron-oxide commercial compounds in the whole investigated frequency range 7 < or = nu < or = 212 MHz. CONCLUSION: PEI-25 was studied as possible MRI contrast agent (CA) to map the cerebral blood volume (CBV) and cerebral blood flow (CBF) in an animal model obtaining promising results. The reported compounds may be further functionalized to afford novel multifunctional systems for biomedical applications.

Protective effect of rhubarb derivatives on amyloid beta (1-42) peptide-induced apoptosis in IMR-32 cells: a case of nutrigenomic.

Amyloid beta (1-42) peptide is considered responsible for the formation of senile plaques that accumulate in the brains of patients with Alzheimer's disease (AD). In the last years considerable attention has been focused on identifying natural food products, such as phytochemicals that prevent or almost retard the appearance of amyloid beta (1-42)-related neurotoxic effects. In this study, human neuroblastoma cells (IMR-32) was used as system model to evaluate the protective role of rhaponticin (3,3',5-trihydroxy-4'-methoxystilbene 3-O-d-glucoside) a stilbene glucoside extracted from rhubarb roots (Rhei rhizoma) and rhapontigenin, its aglycone metabolite, against amyloid beta (1-42)-dependent toxicity. The obtained results show that rhapontigenin maintains significant cell viability in a dose-dependent manner and it exerts a protective effect on mitochondrial functionality, as evidenced by mitochondrial oxygen consumption experiments. A similar behaviour, but to a lesser extent, has been shown by rhaponticin. The protective mechanism mediated by the two stilbenes could be related to their effect on bcl-2 gene family expression. Bax, a pro-apoptotic gene, resulted down-regulated by the treatment with rhaponticin and rhapontigenin compared with the results obtained in the presence of amyloid beta (1-42) peptide. Conversely, bcl-2, an anti-apoptotic gene, highly down-regulated by amyloid beta (1-42) treatment, resulted expressed in the presence of stilbenes similarly to that shown by control cells. The obtained results support the hypothesis that amyloid beta (1-42)-induced neurotoxicity occurs via bax over-expression, bcl-2 down-regulation, firstly indicating that rhaponticin and its aglycone moiety may alter this cell death pathway. Based on these studies, we suggest that rhaponticin and its main metabolite could be developed as agents for the management of AD.

Atomic force microscopy characterization of Xenopus laevis oocyte plasma membrane.

We used atomic force microscopy (AFM) to characterize the plasma membrane of Xenopus laevis oocytes. The samples were prepared according to novel protocols, which allowed the investigation of the extra- and intracellular sides of the membrane, both of which showed sparsely distributed spherical-like protrusions. Regions with comparably sized and densely packed structures arranged in an orderly manner were visualized and dimensionally characterized. In particular, two different arrangements, hexagonal and square packing, were recognizable in ordered regions. The lateral dimension of structures visualized on the external side had a normal distribution centered on 25.5 +/- 0.3 nm (mean value +/- SE), whereas that on the intracellular side showed a normal distribution centered on 30.2 +/- 0.8 nm. The height of the protrusions was 2-5 nm on the external side and 1-3 nm on the intracellular side. The mean number of structures on the external and intracellular sides of the plasma membrane was about 1000 microm(-2) and 850 microm(-2) respectively. Trypsin treatment greatly decreased the size of the membrane protrusions, thus confirming the proteic nature of the structures. These results show that AFM is a useful tool for structural characterization of proteins in a native eukaryotic membrane.

Atomic force microscopy imaging of actin cortical cytoskeleton of Xenopus laevis oocyte.

In this study we report an atomic force microscopy (AFM) investigation of the actin cortical cytoskeleton of Xenopus laevis oocytes. Samples consisted of inside-out orientated plasma membrane patches of X. laevis oocytes with overhanging cytoplasmic material. They were spread on a freshly cleaved mica surface, subsequently treated with Triton X-100 detergent and chemically fixed. The presence of actin fibres in oocyte patches was proved by fluorescence microscopy imaging. Contact mode AFM imaging was performed in air in constant force conditions. Reproducible high-resolution AFM images of a filamentous structure were obtained. The filamentous structure was identified as an actin cortical cytoskeleton, investigating its disaggregation induced by cytochalasin D treatment. The thinnest fibres showed a height of 7 nm in accordance with the diameter of a single actin microfilament. The results suggest that AFM imaging can be used for the high-resolution study of the actin cortical cytoskeleton of the X. laevis oocyte and its modifications mediated by the action of drugs and toxins.

Alzheimer's amyloid beta-peptide (1-42) induces cell death in human neuroblastoma via bax/bcl-2 ratio increase: an intriguing role for methionine 35.

The beta amyloid (Abeta), the major protein component of brain senile plaques in Alzheimer's disease, is known to be directly responsible for the production of free radicals toxic to brain tissue and the redox state of Met-35 residue seems to play a particular and critical role in peptide's neurotoxic actions. In this study, we investigated, in human neuroblastoma cells (IMR-32), the relationship between the oxidative state of methionine, and both neurotoxic and pro-apoptotic actions induced by Abeta-peptide, comparing the effects of native peptide, in which the Met-35 is present in the reduced state, with those of a modified peptide with oxidized Met-35 (Abeta(1-42)(35Met-ox)), as well as an Abeta-derivative with Met-35 substituted with norleucine (Abeta(1-42)(35Nle)). The obtained results show that Abeta induces a time-dependent decrease in cell viability; Abeta(1-42)(35Met-ox) was significantly less potent, though inducing a remarkable decrease in cell viability compared to control. On the contrary, no toxic effects were observed after treatment with Abeta(1-42)(35Nle). Abeta-peptide as well as the amyloid modified peptide with oxidized Met-35 induced the pro-apoptotic gene bax over-expression after 24 h, whereas Abeta(1-42)(35Nle) had no effect. Conversely, bcl-2, an anti-apoptotic gene, became highly down-regulated by Abeta peptide treatment, in contrast to that evidenced by the Abeta(1-42)(35Met-ox) peptide. Finally, Abeta caused an increase in caspase-3 activity to be higher with respect to that shown by Abeta(1-42)(35Met-ox) while Abeta(1-42)(35Nle) had no effect. These results support the hypothesis that Abeta-induced neurotoxicity occurs via bax over-expression, bcl-2 down-regulation, and caspase-3 activation, first indicating that methionine 35 redox state may alter this cell death pathway.

Dioxygenation of naphthalene by Pseudomonas fluorescens N3 dioxygenase: optimization of the process parameters.

The bioconversion of naphthalene to the 1,2-dihydro-1,2-dihydroxy derivative was performed in good yield using an Escherichia coli recombinant strain carrying Pseudomonas fluorescens N3 dioxygenase. However, the efficiency of such transformation is affected by many process parameters, and their optimization is essential to the scaling up of the process. The following process parameters were considered for optimization: cell concentration together with the corresponding glucose concentration (DCW/L); pH of medium; temperature; stirring speed; air flow; substrate concentration; Fe(2+) concentration; microelements concentration; reaction volume. We used a two-step multivariate experimental design to select important variables and assign them optimal values. The most significant parameters were selected by adopting a Plackett-Burman design, and were then correlated, using a full factorial design, with the experimental results. The experimental results illustrate that the optimized process of recombinant whole cell biotransformation in two-liquid phase systems enhances the naphthalene dihydrodiol yield threefold. This biotransformation opens the way to future experiments involving different substrates.

Resveratrol derivatives and their role as potassium channels modulators.

A series of stilbenoid analogues of resveratrol (trans-3,4',5-trihydroxystilbene) with a stilbenic or a bibenzylic skeleton have been prepared by partial synthesis from resveratrol and dihydroresveratrol. The synthesized compounds have been evaluated for their ability to modulate voltage-gated channels.

A comparative study between AFM and SEM imaging on human scalp hair.

A comparative study of AFM and SEM imaging of the same area of a human scalp hair has been carried out to determine the similarity and the differences between the two techniques. Sample preparation for SEM analysis requires a metallization step and vacuum exposure, both of which could potentially induce modifications to the surface details. By contrast, AFM is a suitable technique to evaluate any effect resulting from sample manipulation because it can be applied without any specific treatment. AFM analysis demonstrates that sample metallization is responsible for modifications to the surface details of hair, mainly comprising an increase in height of scale steps and of root mean square roughness together with variation in scale profiles. Sample treatments for SEM imaging are in general potentially responsible for surface modifications to the samples involved.