Rapid quasi-periodic oscillations in the relativistic jet of BL Lacertae.

Blazars are active galactic nuclei (AGN) with relativistic jets whose non-thermal radiation is extremely variable on various timescales1-3. This variability seems mostly random, although some quasi-periodic oscillations (QPOs), implying systematic processes, have been reported in blazars and other AGN. QPOs with timescales of days or hours are especially rare4 in AGN and their nature is highly debated, explained by emitting plasma moving helically inside the jet5, plasma instabilities6,7 or orbital motion in an accretion disc7,8. Here we report results of intense optical and γ-ray flux monitoring of BL Lacertae (BL Lac) during a dramatic outburst in 2020 (ref. 9). BL Lac, the prototype of a subclass of blazars10, is powered by a 1.7 × 108 MSun (ref. 11) black hole in an elliptical galaxy (distance = 313 megaparsecs (ref. 12)). Our observations show QPOs of optical flux and linear polarization, and γ-ray flux, with cycles as short as approximately 13 h during the highest state of the outburst. The QPO properties match the expectations of current-driven kink instabilities6 near a recollimation shock about 5 parsecs (pc) from the black hole in the wake of an apparent superluminal feature moving down the jet. Such a kink is apparent in a microwave Very Long Baseline Array (VLBA) image.

International arrivals: widespread bioinvasions in European Seas.

The European Union lacks a comprehensive framework to address the threats posed by the introduction and spread of marine non-indigenous species (NIS). Current efforts are fragmented and suffer substantial gaps in coverage. In this paper we identify and discuss issues relating to the assessment of spatial and temporal patterns of introductions in European Seas (ES), based on a scientifically validated information system of aquatic non-indigenous and cryptogenic species, AquaNIS. While recognizing the limitations of the existing data, we extract information that can be used to assess the relative risk of introductions for different taxonomic groups, geographic regions and likely vectors. The dataset comprises 879 multicellular NIS. We applied a country-based approach to assess patterns of NIS richness in ES, and identify the principal introduction routes and vectors, the most widespread NIS and their spatial and temporal spread patterns. Between 1970 and 2013, the number of recorded NIS has grown by 86, 173 and 204% in the Baltic, Western European margin and the Mediterranean, respectively; 52 of the 879 NIS were recorded in 10 or more countries, and 25 NIS first recorded in European seas since 1990 have since been reported in five or more countries. Our results highlight the ever-rising role of shipping (commercial and recreational) as a vector for the widespread and recently spread NIS. The Suez Canal, a corridor unique to the Mediterranean, is responsible for the increased introduction of new thermophilic NIS into this warming sea. The 2020 goal of the EU Biodiversity Strategy concerning marine Invasive Alien Species may not be fully attainable. The setting of a new target date should be accompanied by scientifically robust, sensible and pragmatic plans to minimize introductions of marine NIS and to study those present.

Tracking the Spread of the BA.2.86 Lineage in Italy Through Wastewater Analysis.

The emergence of new SARS-CoV-2 variants poses challenges to global surveillance efforts, necessitating swift actions in their detection, evaluation, and management. Among the most recent variants, Omicron BA.2.86 and its sub-lineages have gained attention due to their potential immune evasion properties. This study describes the development of a digital PCR assay for the rapid detection of BA.2.86 and its descendant lineages, in wastewater samples. By using this assay, we analyzed wastewater samples collected in Italy from September 2023 to January 2024. Our analysis revealed the presence of BA.2.86 lineages already in October 2023 with a minimal detection rate of 2% which then rapidly increased, becoming dominant by January 2024, accounting for a prevalence of 62%. The findings emphasize the significance of wastewater-based surveillance in tracking emerging variants and underscore the efficacy of targeted digital PCR assays for environmental monitoring.

New roles of SHOX as regulator of target genes.

The homeobox gene SHOX encodes a transcription factor which is important for normal limb development. Approximately 5 to 10% of short patients exhibit a mutation or deletion in either the SHOX gene or its downstream enhancer regions. In humans, SHOX deficiency has been associated with various short stature syndromes as well as non-syndromic idiopathic short stature. A common feature of these syndromes is disproportionate short stature with a particular shortening of the forearms and lower legs. Madelung deformity, cubitus valgus, high-arched palate and muscular hypertrophy also differed markedly between patients with or without SHOX gene defects. A clinical trial in patients with SHOX deficiency and Turner syndrome demonstrated highly significant growth hormone-stimulated increases in height velocity and height SDS in both groups. Employing microarray analyses and cell culture experiments, a strong effect of SHOX on the expression of the natriuretic peptide BNP and the fibroblast growth factor receptor gene FGFR3 could be demonstrated. We found that BNP was positively regulated, while Fgfr3 was negatively regulated by SHOX. A regulation that occurs mainly in the mesomelic segments, a region where SHOX is known to be strongly expressed, offers a possible explanation for the phenotypes seen in patients with FGFR3 (e.g. achondroplasia) and SHOX defects (e.g. Léri-Weill dyschondrosteosis).

Fractal analysis highlights analogies in arenaceous tubes of Sabellaria alveolata (Metazoa, Polychaeta) and agglutinated tests of foraminifera (Protista).

Bioconstructions of Sabellaria alveolata (Polychaeta Sabellariidae) from southern Sicily (Central Mediterranean) were sampled and analysed through a multidisciplinary approach in order to unravel the construction pattern of arenaceous tubes and explore possible analogies existing between the worm tubes and the agglutinated tests of benthic foraminifera (Protista). Scanning Electron Microscopy and Energy Dispersive Spectroscopy analyses were carried out on entire tubes as well as sectioned ones. Results show that arenaceous tubes are built following a rigorous architectural framework, based on selection and methodical arrangement of the agglutinated grains, and show surprising analogies with the test microstructure previously observed in agglutinated foraminifera. The grain distribution detected in both model species bioconstructions was analysed using a fractal numerical model (Hausdorff fractal dimension). Collected data show that in both organisms the grains were distributed according to a fractal model, indicating that the evolutionary process may have led to finding the same optimal constructive strategy across organisms with an independent evolutionary history, notwithstanding different geometrical scales. Furthermore, in sectioned tubes we observed microplastic fragments agglutinated within the arenaceous wall and in the inter-tube area. This unexpected finding shows that marine animals can be affected by microplastic pollution not only in soft tissues, but also engineered hard structures, and suggests the problem is more pervasive than estimated so far.

Is recreational boating a potential vector for non-indigenous peracarid crustaceans in the Mediterranean Sea? A combined biological and social approach.

Shipping is understood to be a major vector for the introduction and spread of marine non-indigenous species (NIS). However, recreational boating is still unregulated and its influence as vector has not yet been assessed for the Mediterranean Sea, which is the second most popular recreational boating destination worldwide. This is the first large-scale study to examine this by a combined biological (analyzing hull and marina fouling) and social approach (boaters surveys on maintenance habits, travel patterns and awareness), focused on peracarid crustaceans. A surprisingly high number of NIS were found on vessels cruising Mediterranean waters, and species compositions suggest an exchange between marina and vessel assemblages. This means recreational boating presents a risk for NIS spread which should warrant regulation. Results also implied that regionally coordinated management should be supported by effective local-scale-based management in the Mediterranean, which could improve upon with targeted environmental education to solve lack of awareness.

Mmf1p, a novel yeast mitochondrial protein conserved throughout evolution and involved in maintenance of the mitochondrial genome.

A novel protein family (p14.5, or YERO57c/YJGFc) highly conserved throughout evolution has recently been identified. The biological role of these proteins is not yet well characterized. Two members of the p14.5 family are present in the yeast Saccharomyces cerevisiae. In this study, we have characterized some of the biological functions of the two yeast proteins. Mmf1p is a mitochondrial matrix factor, and homologous Mmf1p factor (Hmf1p) copurifies with the soluble cytoplasmic fraction. Deltammf1 cells lose mitochondrial DNA (mtDNA) and have a decreased growth rate, while Deltahmf1 cells do not display any visible phenotype. Furthermore, we demonstrate by genetic analysis that Mmf1p does not play a direct role in replication and segregation of the mtDNA. rho(+) Deltammf1 haploid cells can be obtained when tetrads are directly dissected on medium containing a nonfermentable carbon source. Our data also indicate that Mmf1p and Hmf1p have similar biological functions in different subcellular compartments. Hmf1p, when fused with the Mmf1p leader peptide, is transported into mitochondria and is able to functionally replace Mmf1p. Moreover, we show that homologous mammalian proteins are functionally related to Mmf1p. Human p14.5 localizes in yeast mitochondria and rescues the Deltammf1-associated phenotypes. In addition, fractionation of rat liver mitochondria showed that rat p14.5, like Mmf1p, is a soluble protein of the matrix. Our study identifies a biological function for Mmf1p and furthermore indicates that this function is conserved between members of the p14.5 family.

A biocompatibility study of new nanofibrous scaffolds for nervous system regeneration.

The development of therapeutic approaches for spinal cord injury (SCI) is still a challenging goal to achieve. The pathophysiological features of chronic SCI are glial scar and cavity formation: an effective therapy will require contribution of different disciplines such as materials science, cell biology, drug delivery and nanotechnology. One of the biggest challenges in SCI regeneration is to create an artificial scaffold that could mimic the extracellular matrix (ECM) and support nervous system regeneration. Electrospun constructs and hydrogels based on self-assembling peptides (SAPs) have been recently preferred. In this work SAPs and polymers were assembled by using a coaxial electrospinning setup. We tested the biocompatibility of two types of coaxially electrospun microchannels: the first one made by a core of poly(ε-caprolactone) and poly(d,l-lactide-co-glycolide) (PCL-PLGA) and a shell of an emulsion of PCL-PLGA and a functionalized self-assembling peptide Ac-FAQ and the second one made by a core of Ac-FAQ and a shell of PCL-PLGA. Moreover, we tested an annealed scaffold by PCL-PLGA microchannel heat-treatment. The properties of coaxial scaffolds were analyzed using scanning electron microscopy (SEM), Fourier transform spectroscopy (FTIR), contact angle measurements and differential scanning calorimetry (DSC). In vitro cytotoxicity was assessed via viability and differentiation assays with neural stem cells (NSCs); whereas in vivo inflammatory response was evaluated following scaffold implantation in rodent spinal cords. Emulsification of the outer shell turned out to be the best choice in terms of cell viability and tissue response: thus suggesting the potential of using functionalized SAPs in coaxial electrospinning for applications in regenerative medicine.

The CXXC Zn binding motifs of the human papillomavirus type 16 E7 oncoprotein are not required for its in vitro transforming activity in rodent cells.

The conserved region 3 (CR3) of the E7 protein of human papillomaviruses contains two CXXC motifs involved in zinc binding and in the homodimerization of the molecule. Studies have suggested that the intact CXXC motifs in the CR3 of HPV16 and HPV18 E7 are required for the in vitro transforming activity of these proteins. CR3 also contains a low affinity pRb binding site and is involved in the disruption of the E2F/Rb1 complex. E7 is structurally and functionally related to Adenovirus E1A protein, which also has two CXXC motifs in CR3. However, the Ad E1A transforming activity appears to be independent of the presence of such domains. In fact, this viral protein exists in vivo as two different forms of 289 and 243 amino acids. The shorter Ad E1A form (Ad E1A243), where both CXXC motifs are deleted by internal splicing, retains its in vitro transforming activity. We have investigated if the HPV16 E7 CR3 can be functionally replaced by the Ad E1A243 CR3, which lacks both CXXC motifs. A chimeric protein (E7/E1A243) containing the CR1 and CR2 of HPV16 E7 fused to the CR3 of Ad E1A 243 was constructed. The E7/E1A243 while not able to homodimerize in the S. cerevisiae two-hybrid system retains several of the properties of the parental proteins, HPV16 E7 and Ad E1A. It associates with the 'pocket' proteins, induces growth in soft agar of NIH3T3 cells and immortalizes rat embryo fibroblasts. These data suggest that the CXXC motifs in CR3 of E7 do not play a direct role in the transforming properties of this viral protein but probably are important for maintaining the correct protein configuration.

Human monoclonal antibodies to influenza virus: IgG subclass and light chain distribution.

Three adults and three children were immunized with inactivated or live attenuated influenza vaccines and 98 IgG monoclonal antibodies derived from EBV immortalization of their blood lymphocytes were studied. All antibodies reacted specifically with influenza A H3N2 or H1N1 whole virus and 73 of 74 tested reacted with the purified HA glycoproteins. The majority (76%) of 77 monoclonal antibodies adequately tested by ELISA or solid phase RIA contained lambda light chains. ELISA analysis of the IgG subclass of the six persons' postimmunization anti-influenza serum activity and of monoclonal antibodies derived from them showed a similar predominance of IgG1.

Optimized conditions for the fermentation of Helicobacter pylori and production of vacuolating cytotoxin.

We report here improvements to the growth media and fermentation conditions which result in a substantial increase of Helicobacter pylori growth and in the enhanced production of vacuolating cytotoxin. Addition of glucose to the medium resulted in the increase of cell yield, cell viability and a significant improvement in the production of vacuolating cytotoxin.

Sudden dilatation of right ventricle in two patients with thrombosis of a mitral Björk valve detected by echocardiography: different aspects of acute and chronic overloads of the right ventricle in these patients.

Acute thrombotic obstruction of disc valve prosthesis is a rare but catastrophic event without an immediate correct diagnosis and precocious treatment (Amman et al., 1984; Assanelli et al., 1986; Copans et al., 1980; Mann et al., 1986; Gibson et al., 1974; Johnson et al., 1973; Ledain et al., 1986). That is the main reason it is important to consider each helpful sign in order to recognize such a situation. We detected an important dilatation of the right ventricle in two patients with different stages of thrombosis of mitral Björk, the first one had also a chronic dilatation of the right ventricle due to tricuspid regurgitation. The clinical and pathophysiological aspects of these unusual situations are described in this article.

Differences in proprioception, muscle force control and comfort between conventional and new-generation knee and ankle orthoses.

The aim of this study was to compare muscle force control and proprioception between conventional and new-generation experimental orthoses. Sixteen healthy subjects participated in a single-blind controlled trial in which two different types of orthosis were applied to the dominant knee or ankle, while the following variables were evaluated: muscle force control (accuracy), joint position sense, kinesthesia, static balance as well as subjective outcomes. The use of experimental orthoses resulted in better force accuracy during isometric knee extensions compared to conventional orthoses (P=0.005). Moreover, the use of experimental orthoses resulted in better force accuracy during concentric (P=0.010) and eccentric (P=0.014) ankle plantar flexions and better knee joint kinesthesia in the flexed position (P=0.004) compared to conventional orthoses. Subjective comfort (P<0.001) and preference scores were higher with experimental orthoses compared to conventional ones. In conclusion, orthosis type affected static and dynamic muscle force control, kinesthesia, and perceived comfort in healthy subjects. New-generation experimental knee and ankle orthoses may thus be recommended for prophylactic joint bracing during physical activity and to improve the compliance for orthosis use, particularly in patients who require long-term bracing.

Reversible cerebral vasoconstriction syndrome identification of prognostic factors.

OBJECT: Reversible cerebral vasoconstriction syndrome (RCVS) is described as a clinical and radiological entity characterized by thunderclap headaches, a reversible segmental or multifocal vasoconstriction of cerebral arteries with or without focal neurological deficits or seizures. The purpose of this study is to determine risk factors of poor outcome in patients presented a RCVS. METHODS: A retrospective multi-center review of invasive and non-invasive neurovascular imaging between January 2006 and January 2011 has identified 10 patients with criterion of reversible segmental vasoconstriction syndrome. Demographics data, vascular risks and evolution of each of these patients were analyzed. RESULTS: Seven of the ten patients were females with a mean age of 46 years. In four patients, we did not found any causative factors. Two cases presented RCVS in post-partum period between their first and their third week after delivery. The other three cases were drug-induced RCVS, mainly vaso-active drugs. Cannabis was found as the causative factor in two patient, Sumatriptan identified in one patient while cyclosporine was the causative agent in also one patient. The mean duration of clinical follow-up was 10.2 months (range: 0-28 months). Two patients had neurological sequelae: one patient kept a dysphasia and the other had a homonymous lateral hemianopia. We could not find any significant difference of the evolution between secondary RCVS and idiopathic RCVS. The only two factors, which could be correlated to the clinical outcome were the neurological status at admission and the presence of intraparenchymal abnormalities (ischemic stroke, hematoma) in brain imaging. CONCLUSIONS: Fulminant vasoconstriction resulting in progressive symptoms or death has been reported in exceptional frequency. Physicians had to remember that such evolution could happen and predict them by identifying all factors of poor prognosis (neurological status at admission, the presence of intraparenchymal abnormalities).

Novel adenovirus-based helper system to support production of recombinant parvovirus.

Preclinical studies using various cell culture and animal systems highlight the potential of recombinant rodent parvoviruses (recPVs) for cancer therapy. Production of these viruses is, however, not efficient and this hampers the clinical applications of these agents. In this study, we show that the adenovirus genes E2a, E4(orf6) and VA RNA increase the production of recPVs by more than 10-fold and reduce the time of production from 3 to 2 days in HEK293T cells. The helper effects of these genes can be observed with different recPVs, regardless of the nature and size of the inserted transgene. Furthermore, we generated a recombinant Adenovirus 5 carrying the parvovirus VP transcription unit. This helper, named Ad-VP, allows recPVs to be efficiently produced through a protocol based only on cell infection, making possible to use cell lines, such as NB324K, which are good producers of parvoviruses but are hardly transfectable. Hence, we could further improve viral titers and reduce time and costs of production. This Ad-VP helper-based protocol could be scaled up to a bioreactor format for the generation of the large amounts of recPVs needed for future clinical applications.

Effects of L-nitro-arginine methyl ester, an inhibitor of nitric oxide biosynthesis, on intestinal ischemia/reperfusion injury in rabbits.

To study whether treatment with L-nitro-arginine methyl ester (L-NAME), an inhibitor of nitric oxide biosynthesis, attenuates intestinal dysfunction caused by ischemia (I) and/or reperfusion (R), rabbits were treated with L-NAME (15 mgxkg(-1), intervenously) or saline olution (SS) prior to I (60 minutes) induced by occlusion of superior mesenteric artery and/or R (120 minutes). After I or I/R, isolated jejunal segments (2 cm) were mounted in an organ bath to study nerve-mediated contractions stimulated by electrical pulses or KCI using a digital recording system. Thin jejunal slices were stained (hematoxylin and eosin) for analysis by optical microscopy. Compared with a sham group, the jejunal contractions were similar in the I/R + L-NAME, but reduced in I + SS, I/R + SS, and I + L-NAME groups. The jejunal enteric nerves were damaged in the I + SS, I/R + SS, and I + L-NAME cohorts, but not among the I/R + L-NAME cohort. These results suggested that L-NAME attenuated intestinal dysfunction caused by R but not by I.

Human mesenchymal stem cells derived from bone marrow display a better chondrogenic differentiation compared with other sources.

Mesenchymal stem cells (MSCs) are multipotent cells capable of differentiation into several mesodermal lineages. These cells have been isolated from various tissues, such as adult bone marrow, placenta, and fetal tissues. The comparative potential of these cells originating from different tissues to differentiate into the chondrogenic lineage is still not fully defined. The aim of our study was to investigate the chondrogenic potential of MSCs isolated from different sources. MSCs from fetal and adult tissues were phenotypically characterized and examined for their differentiation capacity, based on morphological criteria and expression of extracellular matrix components. Our results show that both fetal and adult MSCs have chondrogenic potential under appropriate conditions. The capacity of bone marrow-derived MSCs to differentiate into chondrocytes was reduced on passaging of cells. MSCs of bone marrow origin, either fetal or adult, exhibit a better chondrogenesis than fetal lung- and placenta-derived MSCs, as demonstrated by the appearance of typical morphological features of cartilage, the intensity of toluidine blue staining, and the expression of collagen type II, IX, and X after culture under chondrogenic conditions. As MSCs represent an attractive tool for cartilage tissue repair strategies, our data suggest that bone marrow should be considered the preferred MSC source for these therapeutic approaches.