Voltage-gated calcium channels generate blastema Ca 2+ fluxes restraining zebrafish fin regenerative outgrowth.

Adult zebrafish fins regenerate to their original size regardless of damage extent, providing a tractable model of organ size and scale control. Gain-of-function of voltage-gated K + channels expressed in fibroblast-lineage blastema cells promotes excessive fin outgrowth, leading to a long-finned phenotype. Similarly, inhibition of the Ca 2+ -dependent phosphatase calcineurin during regeneration causes dramatic fin overgrowth. However, Ca 2+ fluxes and their potential origins from dynamic membrane voltages have not been explored or linked to fin size restoration. We used fibroblast-lineage GCaMP imaging of regenerating adult fins to identify dynamic and heterogeneous Ca 2+ transients in distal blastema cells. Membrane depolarization of isolated regenerating fin fibroblasts triggered Ca 2+ spikes dependent on voltage-gated Ca 2+ channel activity. Single cell transcriptomics identified the voltage-gated Ca 2+ channels cacna1c (L-type channel), cacna1ba (N-type), and cacna1g (T-type) as candidate mediators of fibroblast-lineage Ca 2+ signaling. Small molecule inhibition revealed L- and/or N-type voltage-gated Ca 2+ channels act during regenerative outgrowth to restore fins to their original scale. Strikingly, cacna1g homozygous mutant zebrafish regenerated extraordinarily long fins due to prolonged outgrowth. The regenerated fins far exceeded their original length but with otherwise normal ray skeletons. Therefore, cacna1g mutants uniquely provide a genetic loss-of-function long-finned model that decouples developmental and regenerative fin outgrowth. Live GCaMP imaging of regenerating fins showed T-type Cacna1g channels enable Ca 2+ dynamics in distal fibroblast-lineage blastemal mesenchyme during the outgrowth phase. We conclude "bioelectricity" for fin size control likely entirely reflects voltage-modulated Ca 2+ dynamics in fibroblast-lineage blastemal cells that specifically and steadily decelerates outgrowth at a rate tuned to restore the original fin size.

Cystic lung diseases: radiological aspects.

Cystic lung diseases (CLDs) are a heterogeneous group of pathophysiological entities comprising gas-filled lesions with imperceptible walls, which can occur throughout lung parenchyma. CLDs can arise from different mechanisms and may often have an unpredictable progression. As CLDs are infrequent and may be associated to many different processes, they pose a diagnostic challenge to the radiologist and referring physician. CLDs require a comprehensive diagnostic approach. An essential tool in the evaluation of CLDs is high-resolution computed tomography (HRCT). The first step is in distinction from true cysts, from other cysts mimicking entities, as emphysema, honeycombing, pneumatocoele, cavitate nodules, or bronchiectasis. Thereafter the identification of number, distribution, wall size, and other systemic manifestations provides an accurate characterisation of CLD, often avoiding further evaluation with lung biopsy. Features of pulmonary lucencies, classification of CLDs based on pathophysiological mechanisms, and radiological criteria, the less common aetiologies, and a multidisciplinary approach in pulmonary cysts are reported. Finally, a systematic diagnostic algorithm to guide radiologists in the evaluation of CLDs is discussed.

DPO: Diffuse Pulmonary Ossification - A Diagnostic Challenge.

Diffuse pulmonary ossification (DPO) is a rare condition of DLD (diffuse lung disease) characterized by the presence of metaplastic ectopic bone in the lungs and is less frequent in patients without a clear background of lung diseases. DPO is characterized by very small calcific nodules, often with bone mature located in both lungs and often in peripheral areas of the lungs. Two patterns of DPO have been recognized dendriform and nodular. The dendriform type is less common and is characterized by a coral-like network of bone spiculae along the alveolar septa and is often related to interstitial fibrosis or chronic obstructive lung disease [1]. Recent literature papers indicate that DPO may be a predictor of pulmonary fibrosis, is related to Usual Interstitial Pneumonia (UIP) pattern, and has a higher correlation with Idiopathic Pulmonary Fibrosis (IPF). We present a case of a 41-years-old male with persistent bronchitis who underwent a chest X-ray (CXR) that showed multiple pulmonary small calcified nodules in both lungs. These findings were then defined with a high-resolution computed tomography of the chest (HRCT) that showed multiple small nodules spread in both lungs with a "tree-like pattern". A lung biopsy was performed to confirm the radiological diagnostic hypothesis of DPO, and further pathological examination showed multifocal areas of mature bone tissue within the lung parenchyma.

The Many Faces of Covid-19: Organizing Pneumonia (OP) Pattern HRCT Features.

Covid-19 (coronavirus disease 2019) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). On 30 January 2020 the World Health Organization (WHO) declared that the outbreak of Covid-19 realizes a public health emergency of international concern. Because of the primary involvement of the respiratory system, chest CT is strongly recommended in suspected Covid-19 cases, for both initial and follow-up. We present the case of a Covid-19 patient, a 57-year-old man, with a typical HRCT course of OP reaction.

The NATO project: nanoparticle-based countermeasures for microgravity-induced osteoporosis.

Recent advances in nanotechnology applied to medicine and regenerative medicine have an enormous and unexploited potential for future space and terrestrial medical applications. The Nanoparticles and Osteoporosis (NATO) project aimed to develop innovative countermeasures for secondary osteoporosis affecting astronauts after prolonged periods in space microgravity. Calcium- and Strontium-containing hydroxyapatite nanoparticles (nCa-HAP and nSr-HAP, respectively) were previously developed and chemically characterized. This study constitutes the first investigation of the effect of the exogenous addition of nCa-HAP and nSr-HAP on bone remodeling in gravity (1 g), Random Positioning Machine (RPM) and onboard International Space Station (ISS) using human bone marrow mesenchymal stem cells (hBMMSCs). In 1 g conditions, nSr-HAP accelerated and improved the commitment of cells to differentiate towards osteoblasts, as shown by the augmented alkaline phosphatase (ALP) activity and the up-regulation of the expression of bone marker genes, supporting the increased extracellular bone matrix deposition and mineralization. The nSr-HAP treatment exerted a protective effect on the microgravity-induced reduction of ALP activity in RPM samples, and a promoting effect on the deposition of hydroxyapatite crystals in either ISS or 1 g samples. The results indicate the exogenous addition of nSr-HAP could be potentially used to deliver Sr to bone tissue and promote its regeneration, as component of bone substitute synthetic materials and additive for pharmaceutical preparation or food supplementary for systemic distribution.

Heterogeneous and self-organizing mineralization of bone matrix promoted by hydroxyapatite nanoparticles.

The mineralization process is crucial to the load-bearing characteristics of the bone extracellular matrix. In this work, we have studied the spatiotemporal dynamics of mineral deposition by human bone marrow mesenchymal stem cells differentiating toward osteoblasts promoted by the presence of exogenous hydroxyapatite nanoparticles. At the molecular level, the added nanoparticles positively modulated the expression of bone-specific markers and enhanced calcified matrix deposition during osteogenic differentiation. The nucleation, growth and spatial arrangement of newly deposited hydroxyapatite nanocrystals have been evaluated using scanning micro X-ray diffraction and scanning micro X-ray fluorescence. As leading results, we have found the emergence of a complex scenario where the spatial organization and temporal evolution of the process exhibit heterogeneous and self-organizing dynamics. At the same time the possibility of controlling the differentiation kinetics, through the addition of synthetic nanoparticles, paves the way to empower the generation of more structured bone scaffolds in tissue engineering and to design new drugs in regenerative medicine.

Posterior mediastinal extramedullary hematopoiesis secondary to hypoxia.

Two mediastinal masses were incidentally detected at high resolution computed tomography (HRCT) of a 72 year-old male patient, former smoker, affected by chronic obstructive pulmonary disease with worsening dyspnea and 2-year medical history of polycythemia secondary to hypoxia. Integration with a multidetector computed tomography (MDCT) scan after administration of intravenous injection contrast medium showed slightly inhomogeneous increase of enhancement of masses, suggesting in the first case potential malignancy. Diagnosis of extramedullary hematopoiesis was achieved by fine needle aspiration citology (FNAC). Extramedullary hematopoiesis must be considered in differential diagnosis in patients with medical history of polycythemia and severe hypoxia.

Exogenous lipoid pneumonia (ELP): when radiologist makes the difference.

Lipoid pneumonia is an uncommon disorder characterized by accumulation of lipid components into the interstitial and alveolar compartment. The usual classification distinguishes endogenous and exogenous and acute or chronic forms, related to the type of fats, the amount of damage and the time of exposure. We describe a case of exogenous lipoid pneumonia by inhalation of vaseline used for cleaning of the tracheostoma in a 63-year-old female, presenting as cough, worsening dyspnea in few weeks. The diagnosis was finally established with a re-evaluation of BAL with specific staining for lipids, revealing the presence of foamy macrophages lipids rich, according to HRCT findings.

Unusual complications of endovascular repair of the thoracic aorta: MDCT findings.

With the development of minimally invasive surgical techniques, endovascular stent-graft placement has become an accepted and widely used alternative to the traditional surgical repair of aortic disease and is gaining acceptance as the treatment of choice. Many studies show that endovascular stent-graft therapy is safe and effective, although complications related to this treatment are also recognised. Although the incidence of major complication is low, neurological sequelae remain the major concern of endovascular repair. With growing experience, however, the spectrum of mid- and long-term complications has broadened to include potentially disastrous events, other than paraplegia or stroke, that require diligent surveillance. Three-dimensional data sets acquired quickly by multidetector computed tomography (MDCT) allow multiplanar reformations and 3D viewing, as well as quantitative assessment of vessel lumens, walls and surroundings. Although a large portion of radiologists will not be involved in the actual endograft deployment, many will be involved in the interpretation of postprocedural surveillance studies. Accordingly, the goal of this report is to summarise our experience with the presentation, diagnostic approach, management and outcomes of these unusual, but potentially catastrophic, postendovascular aortic repair complications to highlight their significance and increase familiarity with them among the imaging community. Increasing awareness of these complications may facilitate rapid diagnosis and/or triage and treatment.

Technological applications of chlorophyll a fluorescence for the assessment of environmental pollutants.

Chlorophyll a fluorescence has been extensively studied over the last few years. As demonstrated, this phenomenon is closely related to the state of photosystem II, which plays a leading role in the photosynthetic process, and therefore it has become a powerful tool to investigate this complex and any damage occurring in it as a result of physical or chemical stresses. This means that by using photosynthetic organisms as biological probes, one can consider chlorophyll a fluorescence as one of the techniques of choice to reveal the presence of some hazardous toxicants widely spread in the environment. Herbicides, pesticides, and heavy metals, whose concentration in water and food products is generally subject to extremely severe restrictions, are a concrete example of compounds detectable by chlorophyll a fluorescence. These dangerous substances react with the photosystem II, modifying the fluorescence emitted and giving responses which vary in a concentration-dependent manner. The possibility of performing easy, fast, and direct measurements of the fluorescence, even under light conditions, has opened new frontiers for the analysis in situ of pollutants. The aim of this review is to give an overview of the different techniques based on chlorophyll a fluorescence spectrometry, focusing in particular on those which represented the starting point for applications addressed to the assessment of toxic compounds in environmental samples.

Adult-onset pulmonary involvement in Niemann-Pick disease type B.

Niemann-Pick disease type B is caused by a deficiency in acid sphingomyelinase activity; among the six variants of Niemann-Pick disease known to date, it is the most frequently associated with lung involvement, a major cause of morbidity and mortality in this subtype in patients of all ages. Nevertheless, the vast majority of reports in the literature concern infantile forms, while less reported is, for several reasons, the onset in adults being consequently still poorly understood and characterized its clinical, radiographic and functional manifestations. We report a case of a 37 years-old female patient affected by subtype B since she was an infant, operated for aortic valve replacement two years before and came to our attention for the onset of a worsening exertional dyspnoea which proved, through a series of functional tests and radiological exams, to be a consequence of the diffuse lung involvement by the metabolic disorder; we performed a review on this topic through a Medline search of all the available "adult-onset" case reports published since the first description in 1964, also considering the possible association between NPDB and, more generally lysosomal storage disorders, and the valvular disease, already suggested by several Authors in previous works.

Primary pleural haemangioendothelioma in an Italian female patient: a case report and review of the literature.

Primary epithelioid haemangioendothelioma (EHE) of the pleura is a rare vascular tumour that occurs mainly in men. Pleural effusion and thickening are the most common clinical presentations. A 58 year old female, nonsmoking patient presented to us with dry cough, dyspnoea and left chest pain for several weeks (no asbestos exposure). Standard chest X-ray and contrast enhanced multislice computed tomography revealed a large-size lobulated mass originating from the pleura which was diagnosed as primary pleural haemangioendothelioma (PHE) by histology and immunohistochemistry (reactivity for vimentin, CD31, CD34, Factor VIII and ulex europeaus). No metastases were detected. The patient refused treatment and died three months later due to the onset of acute and progressive respiratory failure. Despite the lack of high-grade malignancy, primary PHE displays a poor prognosis while curative therapies are actually not available. To our knowledge, this is the first case of primary PHE in a female patient occurring in Italy and the third one to have been reported in English literature. Difficulties in diagnosis and treatment management are discussed below.

Chlamydomonas reinhardtii genetic variants as probes for fluorescence sensing system in detection of pollutants.

The unicellular green alga Chlamydomonas reinhardtii is employed here for the setup of a biosensor demonstrator based on multibiomediators for the detection of herbicides. The detection is based on the activity of photosystem II, the multienzymatic chlorophyll-protein complex located in the thylakoid membrane that catalyzes the light-dependent photosynthetic primary charge separation and the electron transfer chain in cyanobacteria, algae, and higher plants. Several C. reinhardtii mutants modified on the D1 photosystem II protein are generated by site-directed mutagenesis and experimentally tested for the development of a biosensor revealing the modification of the fluorescence parameter (1 - V (J)) in the presence of herbicides. The A250R, A250L, A251C, and I163N mutants are highly sensitive to the urea and triazine herbicide classes; the newly generated F255N mutant is shown to be especially resistant to the class of urea. It follows that the response of the multibiomediators is associated to a particular herbicide subclass and can be useful to monitor several species of pollutants.

CSF shunt removal in children with hydrocephalus.

The possibility to remove a previously inserted CSF shunt device in hydrocephalic children is a well known though rare event for paediatric neurosurgeons. A retrospective analysis of our experience with a series of 850 children affected by non tumoral hydrocephalus shows that obvious shunt independence could be demonstrated in 3.2% of the patients (27 cases). The time interval between the CSF shunt insertion and removal ranged between 8 months and 12 years (mean: 8 years). Parameters analysed to search for any predictive elements were age at surgery, aetiology, type of prosthesis utilised, time interval between insertion and removal of the shunt, number of the possible revisions. The results of the study suggest that the highest incidence of shunt independence is reached in subjects operated on in early infancy, as 24 of 27 removed shunts were in patients operated on under 6 months of age, and the remaining in 2 children treated when less than 2 years old. Such a finding could be explained on the grounds of a delay in maturation of the CSF absorption mechanisms followed by a late normalisation in these patients. As regards to aetiology, 41% of the 27 patients considered in this series were affected by a post-haemorrhagic hydrocephalus, which was progressive, as demonstrated by serial neuroradiological examinations and echo-Doppler cerebral studies at the time of the surgical treatment. In six children the hydrocephalus was associated with myelomeningocele. Five patients had aqueduct stenosis and 2 communicating hydrocephalus. The types of CSF shunting system we utilised did not play any role in determining or facilitating shunt independence. No correlation was observed with the need and the number of shunt revisions. The role of the interval time between the insertion and the removal of the shunt was not analysable, because of the possible acquisition of the shunt independence prior to its demonstration at the moment of the surgical revision of the CSF shunt (elective lengthening because of the physiological body growth) or to the radiological demonstration of CSF shunt device disconnection. The same constraint prevents the evaluation of the actual overall incidence of shunt independence in shunted hydrocephalic children, as some of them could have harboured a non-functioning CSF shunt device, though unnoticed.

Reproductive decision making before and after predictive testing for Huntington's disease: an Australian perspective.

A retrospective study examined both pre- and post-result reproductive decision making for 281 people at risk for Huntington's disease aged 18-45 years who had undergone predictive testing in one centre in Australia between 1990 and 2002. Forty-eight per cent of subjects had one or more pre-result pregnancies, and of these, three had prenatal linkage testing. One high-risk (50%) pregnancy was terminated. Four couples chose an alternative reproductive option. Following testing, data were available for 231 subjects, and no significant difference was found between mutation carriers and non-carriers in the occurrence of post-result pregnancies. This contrasts with the finding of a recent European study, although the outcome of the present study may have been influenced by loss of follow-up data for 50 subjects. Five carriers (17%) had a total of six prenatal tests. Four showed a carrier result and these pregnancies were terminated. Two carriers utilized an alternative reproductive option (donor insemination and pre-implantation genetic diagnosis). The results of this study confirm previous findings of a low uptake of prenatal testing and alternative reproductive options by people at risk for Huntington's disease undergoing predictive testing.

[MR imaging in the follow-up of ACL reconstruction: retrospective analysis of 54 patients]. / La RM nel follow-up degli interventi di sostituzione del LCA di ginocchio: analisi retrospettiva di 54 pazienti.

PURPOSE: The authors evaluated the possible presence of lesions, in patients treated for anterior cruciate ligament (ACL) reconstruction. MATERIAL AND METHODS: MR examinations of the knee were performed in 54 patients previously surgically treated for an ACL lesion, with a patellar tendon graft. MR was performed in a period of time ranging from 10 to 36 months after surgery. The authors studied the new ligament, transosseous tunnel location, the patellar tendon, other possible articular lesions and the extent and signal of possible synovial fibrotic reaction. RESULTS: Lesions of the new ligament were found in 21 patients with the following patterns: atrophic reabsorption of the new-ACL (6 patients), and diffuse or focal alterations in morfology and signal (15 patients). In 15 patients the new ACL lesions were associated with incorrect positioning of tibial tunnels. All of the new ligament lesions diagnosed with MR were arthroscopically confirmed. In 12 patients the patellar tendon in 12 patients was involved with inflammatory-degenerative alterations. Other associated lesions were found involving menisci (18 patients), medial collateral ligament (MCL) (8 patients), osteochondral surfaces (12 patients). In patients with an intact new ACL, instability was correlated with meniscal lesions associated with MCL irregularities. In 4 patients a diffuse fibrotic synovial tissue was responsible for limited articular excursion. CONCLUSIONS: MR in post-ACL substitution has to panoramically investigate all articular compartments, with a complete evaluation of all articular lesions that can contribute to articular symptomatology in order to choose the correct therapeutic strategy.

[Role of flowmetric analysis and of color-Doppler ultrasonography with contrast media in the different phases and follow-up of Graves' disease]. / Ruolo dell'analisi flussimetrica e dell'eco color-Doppler con mdc nelle differenti fasi e nel follow-up della malattia di Graves.

PURPOSE: The objectives of this study were: 1) to evaluate the role of color-Doppler ultrasonography (CDU) assessment of thyroid vascularity, measuring the peak systolic velocity (PSV) at the level of the inferior thyroid artery, and the intrathyroid vascularization in Graves' diseas; 2) to evaluate the role of contrast agent administration in predicting the relapse of hyperthyroidism or the biological activity of the disease after withdrawal of antithyroid drugs. PATIENTS AND METHOD: The study included 74 Graves' patients (59 F/ 15 M; mean age 45 years; range 23-71). Graves' disease was diagnosed according to the usual clinical and laboratory criteria. On the basis of the clinical and biochemical findings we divided Graves' patients into 4 different groups. Treatment was continued for at least 12 months, CDU examination was carried out after discontinuing therapy. Eight patients showed a relapse of hyperthyroidism within 5 months after suspension of therapy. In all cases the evaluation of intraparenchymal vascularization and PSV at the level of the inferior thyroid artery in basal conditions was followed by administration of contrast agent (Levovist, 300 mg/ml), with slow infusion (<2 ml/min) to avoid blooming artifact. Intraparenchymal vascularization was classified into 4 patterns according to Vitti et al. RESULTS: The value of the peak systolic velocity (PSV) at the level of the inferior thyroid artery was the best predictor of relapse. A value higher than 40 cm/sec was present in all the patients that showed relapse and only in two patients with stable remission. Administration of contrast agent is important to evaluate the biological activity of the disease. In the 5 patients exhibiting slightly increased vascularization after contrast agent administration we could assume the clinico-pathological recovery. CONCLUSIONS: CDU study of thyroid vascularization, based on the measurement of PSV at the level of the inferior thyroid artery and on the response to contrast agent administration is useful to distinguish three groups of patients: A) PSV >40 cm/sec with pattern III for at least 10 minutes from the beginning of the contrast agent administration (High risk of relapse); B) PSV <40 cm/sec with pattern II or III after contrast agent administration (Biological activity of the disease-Thyroiditis); C) PSV <40 cm/sec with Pattern I after contrast agent administration (Poor biological activity of the disease-recovery).