Impact of ablation index settings on pulmonary vein reconnection.

PURPOSE: Ablation index (AI) is a radiofrequency lesion quality marker. The AI value that allows effective and safe pulmonary vein isolation (PVI) is still debated. We evaluated the incidence of acute and late PV reconnection (PVR) with different AI settings and its predictors. METHODS: The Ablation Index Registry is a multicenter study that included patients with paroxysmal/persistent atrial fibrillation (AF) who underwent first-time ablation. Each operator performed the ablation using his preferred ablation catheter (ThermoCool® SmartTouch or Surround Flow) and AI setting (380 posterior-500 anterior and 330 posterior-450 anterior). We divided the study population into two groups according to the AI setting used: group 1 (330-450) and group 2 (380-500). Incidence of acute PVR was validated within 30 min after PVI, whereas the incidence of late PVR was evaluated at repeat procedure. RESULTS: Overall, 490 patients were divided into groups 1 (258) and 2 (232). There was no significant difference in the procedural time, fluoroscopy time, and rate of the first-pass PVI between the two study groups. Acute PVR was observed in 5.6% PVs. The rate of acute PVR was slightly higher in group 2 (64/943, 6.8%, PVs) than in group 1 (48/1045, 4.6% PVs, p = 0.04). Thirty patients (6%) underwent a repeat procedure and late PVR was observed in 57/116 (49%) PVs (number of reconnected PV per patient of 1.9 ± 1.6). A similar rate of late PVR was found in the two study groups. No predictors of acute and late PVR were found. CONCLUSION: Ablation with a lower range of AI is highly effective and is not associated with a higher rate of acute and late PVR. No predictors of PV reconnection were found.

Combined Methodologies for Determining In Vitro Bioavailability of Drugs and Prediction of In Vivo Bioequivalence From Pharmaceutical Oral Formulations.

With the aim of developing an in vitro model for the bioavailability (BA) prediction of drugs, we focused on the study of levonorgestrel (LVN) released by 1.5 mg generic and brand-name tablets. The developed method consisted in combining a standard dissolution test with an optimized parallel artificial membrane permeability assay (PAMPA) to gain insights into both drug release and gastrointestinal absorption. Interestingly, the obtained results revealed that the tablet standard dissolution test, combined with an optimized PAMPA, highlighted a significant decrease in the release (15 ± 0.01 µg min-1 vs 30 ± 0.01 µg min-1) and absorption (19 ± 7 × 10-6 ± 7 cm/s Pe vs 41 ± 15 × 10-6 cm/s Pe) profiles of a generic LVN tablet when compared to the brand-name formulation, explaining unbalanced in vivo bioequivalence (BE). By using this new approach, we could determine the actual LVN drug concentration dissolved in the medium, which theoretically can permeate the gastrointestinal (GI) barrier. In fact, insoluble LVN/excipient aggregates were found in the dissolution media giving rise to non-superimposable dissolution profiles between generic and brand-name LVN tablets. Hence, the results obtained by combining the dissolution test and PAMPA method provided important insights confirming that the combined methods can be useful in revealing crucial issues in the prediction of in vivo BE of drugs.

Development of an UHPLC-diode arrays detector (DAD) method for the analysis of polydatin in human plasma.

A new chromatographic method by Ultra High Performance Liquid Chromatographic (UHPLC) technology, has been developed and validated for the determination of polydatin and resveratrol, as potential metabolite, in human plasma. After the optimization of the chromatographic conditions, the method has been validated on spiked human plasma samples. The optimized extraction allowed to obtain analytes recovery up to 98.48 ± 4.03 %. Then, the isocratic elution in reversed phase mode, provides the separation of polydatin and resveratrol in less than 10.0 min. Chromatographic analysis was performed on a C18, 10 cm x 3.0 mm, 2.7 µm stationary phase, by using triethanolamine phosphate solution (0.1 M, pH = 3.7) and ACN 85:15 (v/v) as mobile phase at a flow rate of 0.5 mL/min. The UV detector was set at 306 nm for the analysis of both polydatin and resveratrol. The limit of detection (LoD) and the limit of quantification (LoQ) for polydatin in plasma samples were found to be 7.82 ± 0.38 nM and 26.06 ± 1.28 nM respectively. The method was found to be accurate and precise with a coefficient for intra- and inter-day variation below 5 %. All the reported data demonstrate how the developed method is rapid and sensitive. Moreover, results of the analysis of plasma samples, obtained from orally treated volunteers with nutritional supplements containing polydatin, have shown the method to be suitable for the pharmacokinetic characterization of polydatin and resveratrol, as metabolite, in humans.

Long-term disease outcome and volume-based decision strategy in a large cohort of multiple brain metastases treated with a mono-isocentric linac-based Stereotactic Radiosurgery technique.

PURPOSE: Radiosurgery (SRS) is an effective treatment option for brain metastases (BMs). Long-term results of the first worldwide experience with a mono-isocentric, non-coplanar, linac-based stereotactic technique in the treatment of multiple BMs are reported. METHODS: patients with multiple BMs, life expectancy > 3 months, and good performance status (≤ 2) were treated with simultaneous SRS with volumetric modulated arc technique. Data were retrospectively evaluated. RESULTS: 172 patients accounting for 1079 BMs were treated at our institution from 2017 to 2020. The median number of treated metastases was 4 (range 2-22). Primary tumor histology was: lung (44.8%), breast (32%), and melanoma (9.4%). The 2-year LPFS was 71.6%, respectively. A biological effective dose (BED) ≥ 51.3 Gy10 correlated with higher local control. Uncontrolled systemic disease and melanoma histology were independent prognostic factors correlated with decreased iPFS. Patients with > 10 BMs had a trend towards shorter iPFS (p = 0.055). 31 patients received multiple SRS courses (2-7) in case of intracranial progression. The median iOS was 22.4 months. Brainstem metastases and total PTV > 7.1 cc correlated with shorter iOS. The 1- and 2-year WBRT-free survival was 83.2% and 61.1%, respectively. CONCLUSION: Long-term results in a large patient population treated with a mono-isocentric, dedicated technique demonstrated its effectiveness and safety also in the case of multiple courses. The shortened treatment time and the possibility to safely spare healthy brain tissue allows the safe treatment of patients with a large number of metastases and to deliver multiple courses of SRS. In selected cases, the administration of WBRT can be delayed.

Mixing and matching methylotrophic enzymes to design a novel methanol utilization pathway in E. coli.

One-carbon (C1) compounds, such as methanol, have recently gained attention as alternative low-cost and non-food feedstocks for microbial bioprocesses. Considerable research efforts are thus currently focused on the generation of synthetic methylotrophs by transferring methanol assimilation pathways into established bacterial production hosts. In this study, we used an iterative combination of dry and wet approaches to design, implement and optimize this metabolic trait in the most common chassis, E. coli. Through in silico modelling, we designed a new route that "mixed and matched" two methylotrophic enzymes: a bacterial methanol dehydrogenase (Mdh) and a dihydroxyacetone synthase (Das) from yeast. To identify the best combination of enzymes to introduce into E. coli, we built a library of 266 pathway variants containing different combinations of Mdh and Das homologues and screened it using high-throughput 13C-labeling experiments. The highest level of incorporation of methanol into central metabolism intermediates (e.g. 22% into the PEP), was obtained using a variant composed of a Mdh from A. gerneri and a codon-optimized version of P. angusta Das. Finally, the activity of this new synthetic pathway was further improved by engineering strategic metabolic targets identified using omics and modelling approaches. The final synthetic strain had 1.5 to 5.9 times higher methanol assimilation in intracellular metabolites and proteinogenic amino acids than the starting strain did. Broadening the repertoire of methanol assimilation pathways is one step further toward synthetic methylotrophy in E. coli.

Advances in modelling alpha-synuclein-induced Parkinson's diseases in rodents: Virus-based models versus inoculation of exogenous preformed toxic species.

Aggregates of alpha-synuclein (αSyn) have been described in Parkinson's disease (PD) patients, and recent evidence has suggested that the most toxic αSyn species in PD are small soluble aggregates including oligomers, prefibrils, protofibrils. The physiological function of αSyn is still highly debated, with a possible role in synaptic vesicle trafficking and release at the presynaptic compartment, and in the regulation of gene expression in the nucleus. Emerging evidence indicate that most of αSyn functions are related with the crucial ability to bind biological membranes, which is associated with structural conversion from a disordered monomer to an α-helical enriched structure. Conformational properties of αSyn can be modulated by a number of factors including post-translational modifications, gene duplication and triplication-driven overexpression, single point mutations, environmental changes, which affect membrane binding and the protein propensity to aggregate in toxic species. The recognized toxic role of αSyn in PD has laid the rational for purposing of αSyn-based, neuropathologically relevant preclinical models of PD. Different approaches have led to the establishment of transgenic models, viral vector-based models, and more recently models based on the intracerebral inoculation of exogenous αSyn preformed fibrils/oligomers. Here, we overview and compare viral vector-based models of αSyn overexpression and models obtained by direct intracerebral infusion of in vitro preformed αSyn species. The advantages and pitfalls associated with these different approaches are discussed.

A neutrally stable shell in a Stokes flow: a rotational Taylor's sheet.

In a seminal paper published in 1951, Taylor studied the interactions between a viscous fluid and an immersed flat sheet which is subjected to a travelling wave of transversal displacement. The net reaction of the fluid over the sheet turned out to be a force in the direction of the wave phase-speed. This effect is a key mechanism for the swimming of micro-organisms in viscous fluids. Here, we study the interaction between a viscous fluid and a special class of nonlinear morphing shells. We consider pre-stressed shells showing a one-dimensional set of neutrally stable equilibria with almost cylindrical configurations. Their shape can be effectively controlled through embedded active materials, generating a large-amplitude shape-wave associated with precession of the axis of maximal curvature. We show that this shape-wave constitutes the rotational analogue of a Taylor's sheet, where the translational swimming velocity is replaced by an angular velocity. Despite the net force acting on the shell vanishes, the resultant torque does not. A similar mechanism can be used to manoeuver in viscous fluids.

Uncovering the balance of forces driving microtubule aster migration in C. elegans zygotes.

Microtubule asters must be positioned precisely within cells. How forces generated by molecular motors such as dynein are integrated in space and time to enable such positioning remains unclear. In particular, whereas aster movements depend on the drag caused by cytoplasm viscosity, in vivo drag measurements are lacking, precluding a thorough understanding of the mechanisms governing aster positioning. Here, we investigate this fundamental question during the migration of asters and pronuclei in C. elegans zygotes, a process essential for the mixing of parental genomes. Detailed quantification of these movements using the female pronucleus as an in vivo probe establish that the drag coefficient of the male-asters complex is approximately five times that of the female pronucleus. Further analysis of embryos lacking cortical dynein, the connection between asters and male pronucleus, or the male pronucleus altogether, uncovers the balance of dynein-driven forces that accurately position microtubule asters in C. elegans zygotes.

Neurological manifestations in dogs naturally infected by Leishmania infantum: descriptions of 10 cases and a review of the literature.

In order to evaluate possible nervous system involvement in canine leishmaniasis, retrospective evaluation of all medical records of leishmaniotic dogs exhibiting neurological signs referred to our hospital over a 5-year period was performed. The records of 10 dogs were reviewed. Depending on the neuroanatomical localisation, the dogs underwent advanced diagnostic imaging, cerebrospinal fluid analysis, electrodiagnostic testing and histopathologic evaluations. The final neurological diagnosis was: meningoencephalitis (n=2), brain haemorrhagic stroke (n=1), haemorrhagic choroiditis (n=1), meningomyelitis (n=2), ischaemic myelopathy (n=1), polymyositis (n=2) and peripheral neuropathy (n=1). This study confirms that both central and peripheral nervous systems can be affected by leishmaniasis and provides an overview on the possible etiopathogenetic mechanisms. In addition, clinical and diagnostic findings, therapy and follow-up of affected dogs are described.

Bilateral cervical ribs in a Dobermann Pinscher.

An 11-year-old intact female Doberman Pinscher was presented with the complaint of non-ambulatory tetraparesis. Clinical and neurological examination revealed a caudal cervical spinal cord disfunction (C6-T2 spinal cord segments). Magnetic resonance imaging and computed tomographic (CT) findings of the cervical spine were consistent with caudal cervical spondylomyelopathy (CSM). During the diagnostic work-up for the cervical spine, bilateral bone anomalies involving the seventh cervical vertebra and the first ribs were found on radiographs and CT examination. The rib anomalies found in this dog appear similar to cervical ribs widely described in human medicine. In people, cervical ribs are associated with a high rate of stillbirth, early childhood cancer, and can cause the thoracic outlet syndrome, characterized by neurovascular compression at level of superior aperture of the chest. In dogs, only some sporadic anatomopathological descriptions of cervical ribs exist. In this report the radiographic and CT findings of these particular vertebral and rib anomalies along with their relationships with adjacent vasculature and musculature are shown intravitam in a dog. Specific radiographic and CT findings described in this report may help in reaching a presumptive diagnosis of this anomaly. Finally, their clinical and evolutionary significance are discussed.

Extradural spinal cord lesion in a dog: first case study of canine neurological histoplasmosis in Italy.

A 7-year-old intact male mixed dog was presented with a history of acute and progressive paraparesis. Abnormal clinical signs consisted of non-ambulatory paraparesis, hind limbs hypertonia and severe thoracolumbar pain. Magnetic resonance imaging demonstrated an isointense in T1 and T2 WI epidural lesion, with good contrast enhancement, extending from T-10 to T-13. Laminectomy was carried out to remove the epidural mass. Histological examination revealed a pyogranulomatous lesion characterized by numerous macrophages containing yeast-like Grocott and PAS-positive bodies. Immunohistochemistry and PCR performed on formalin-fixed paraffin-embedded tissue confirmed Histoplasma capsulatum as the causative agent. H. capsulatum has a worldwide distribution in temperate and subtropical climates but its presence as an autochthonous fungus in Europe is now recognized. To the authors' knowledge this is the first report of canine histoplasmosis in Italy with lesion confined to the central nervous system.

A sacro-caudal spinal cord choroid plexus papilloma in a shar-pei dog.

A seven-year-old shar-pei dog was referred because of severe lumbosacral pain and faecal incontinence of 20 days' duration. Neurological examination was characterised by plegic tail, absence of perineal reflex, dilated anus, perineum and tail analgesia, and severe lumbosacral pain. The neurological clinical signs were suggestive of a selective lesion involving sacral and caudal spinal cord segments and/or related nerve roots. A magnetic resonance imaging of lumbosacral spine was performed and was suggestive of an intradural lesion. Primary or secondary neoplasia was considered as the most probable differential diagnosis. The dog was euthanased upon the owner's request. Histopathological examination confirmed the presence of an intradural-extramedullary neoplastic tissue enveloping intradural tract of spinal nerve roots. On the basis of histological and immunohistochemical findings, a diagnosis of well-differentiated choroid plexus papilloma was made. To the authors's knowledge, this is the first case of primary or metastatic spinal choroid plexus papilloma in dogs.

Heavy metals in canned tuna from Italian markets.

Fish is a good source of nutrients for humans but can pose a risk to human health because of the possible presence of some xenobiotics such as heavy metals and persistent organic contaminants. Constant monitoring is needed to minimize health risks and ensure product quality and consumer safety. The aim of the present study was to use atomic absorption spectrometry to determine the concentrations of some heavy metals (Hg, Pb, and Cd) in tuna packaged in different kinds of packages (cans or glass) in various countries (Italy and elsewhere). Concentrations of Cd and Hg were within the limits set by European Commission Regulation (EC) No 1881/2006 and in many samples were below the detection limit. Pb concentrations exceeded European limits in 9.8% of the analyzed samples. These results are reassuring in terms of food safety but highlighted the need to constantly monitor the concentrations of heavy metals in fish products that could endanger consumer health.

Software for hepatic vessel classification: feasibility study for virtual surgery.

PURPOSE: The detection and classification of hepatic vessels in diagnostic images are essential for hepatic pre-surgery planning. Our team has developed a tool for classification, analysis, and 3D reconstruction of the hepatic and portal systems. METHODS: Our software first extracts a graphic representation of a set of connected voxels, representing both systems. It then calculates two binary volumes representing the main part of the two venous systems. Finally, it combines these results to obtain the correct vessel classification. RESULTS: Segmentation steps are semi-automatic and require about 40 min to complete. Schematization and classification steps are automatic and require about 17 min for results. CONCLUSION: The software provides a correct and detailed reconstruction even where pathologies have caused morphological and geometrical variations in the vessels. The time required for the entire procedure is compatible with clinical requirements, providing an efficient tool for diagnosis and surgical planning.

[Vacuum-assisted breast biopsy for diagnosis of non-palpable lesions: experience with 226 cases]. / Biopsia mammaria "vacuum-assisted" per la diagnosi di lesioni non palpabili: descrizione dei primi 226 casi.

Vacuum-assisted breast biopsy (VABB) is now available for non-palpable lesions. The present study describes the results obtained from 226 consecutive VABBs performed at "L. Sacco" Hospital, Milan, from November 2005 to July 2007 (198 stereotactic and 28 ultrasonographic procedures). Adequate tissue samples for histopathological evaluation were obtained in 225 cases (99.6%). The diagnoses were as follows: 9 normal tissues (4%), 97 benign (43%), 25 "probably benign" (11%), 4 "suspicious for malignancy" (2%) and 90 malignant (40%, 53 in situ and 37 infiltrating carcinoma). Of the 90 malignant cases, 38 (42.2%) underwent subsequent surgical excision in our Unit; 84.2% (32/38) had concordant histopathological findings. In conclusion, VABB is an accurate and safe technique for diagnosis of non-palpable lesions, and in experienced hands avoids unnecessary surgical procedures.

Structure and expression of a novel gene family showing male germline specific expression in Drosophila melanogaster.

We report the characterization of two novel genes of Drosophila melanogaster, named mst36Fa and mst36Fb. They define a novel gene family, showing identical time and tissue-specificity limited to male germ cells where their transcription starts during meiotic prophase. These two genes encode for two slightly basic proteins highly homologous to each other and fairly rich in leucine and glutamic acid. Although strictly clustered, these genes utilize different promoter regions as revealed by examination of transgenic flies bearing mst36F-promoter-lacZ reporter constructs and by reverse transcription-polymerase chain reaction assays. Our data suggest that at least one gene (mst36Fa) of the cluster is under translational repression until spermiogenesis suggesting a putative role in the spermatides differentiation. The present study is aimed at the structural analysis of these genes.

[Aspects of the on-line hemodiafiltration with regeneration and reinfusion of the ultrafiltrate (HFR): multicenter study]. / Aspetti dell'emodiafiltrazione on-line con rigenerazione e reinfusione dell'ultrafiltrato (HFR): uno studio multicentrico.

Despite technological advances in dialysis treatment, survival, morbidity and the quality of life in hemodialysis (HD) patients are affected by long-term complications, often related to the treatment itself. Among these complications, moderate protein and caloric malnutrition are present in approximately 30% of dialysis patients and are viewed as major contributors to increased mortality. In malnutrition pathogenesis, great importance is given to protein catabolism and to the loss of somatic protein and amino acids during dialysis. On the contrary, toxin clearance is believed to influence, positively, both protein anabolism and dietary protein intake. In hemodiafiltration (HDF), the clearance process is potentiated by three mechanisms (diffusion, convection and adsorption) and this could have a favorable effect on malnutrition. In addition, the reinfusion of regenerated ultrafiltrate (UF) would avoid the loss of large amounts of useful solutes as occurs with standard HD. In fact, all amino acids are present in the UF, which is not important in standard HD, but could be a problem in hemodiafiltration reinfusion (HFR). We treated 16 patients with HFR during the previous 3 months (the study will last for 12 months). Patients had been previously treated with bicarbonate dialysis for at least 6 months. The clinical tolerance of HFR was excellent and the technique appeared to be quite simple. The preliminary biochemical results demonstrated the stabilization of some parameters (such as urea and uric acid) with an adequate clearance of small molecules, while variables related to nutritional status (body weight, serum albumin and serum transferrin) did not change substantially. Surprisingly, the loss of both branched chain amino acids (BCAA) and essential amino acids (EAA) seemed slightly lower in HFR compared with standard HD. However, the reduced loss of amino acids (AA) observed with HFR should take into account other factors, such as absorption on adsorbent material and the basal plasma AA concentrations. Therefore, although each patient is in control of himself, it is difficult to draw any definite conclusions after only 3 months. However, it is evident that the loss of AA in HFR is quite modest and is not increased by the fact that it is a hemofiltration technique with all the consequent positive effects.

Response to flecainide infusion predicts long-term success of hybrid pharmacologic and ablation therapy in patients with atrial fibrillation.

OBJECTIVES: We tested the hypothesis that the response to flecainide infusion can identify patients with atrial fibrillation (AF) in whom the hybrid pharmacologic and ablation therapy reduces the recurrences of AF. BACKGROUND: Infusion of class IC anti-arrhythmic drugs may promote transformation of AF into atrial flutter. Catheter ablation of atrial flutter has been demonstrated to be highly effective in preventing recurrences of atrial flutter. METHODS: Seventy-one consecutive patients with paroxysmal or chronic AF, in whom flecainide infusion (2 mg/kg body weight, intravenously) determined the transformation of AF into common atrial flutter (positive response), were randomized to receive one of the following treatments: oral pharmacologic treatment with flecainide (group A, n = 23); the hybrid treatment (catheter ablation of the inferior vena cava-tricuspid annulus isthmus, plus oral flecainide) (group B, n = 24); or catheter ablation of the isthmus only (group C, n = 24). Thirty-seven patients with a negative response to flecainide, who chose to be submitted to the hybrid treatment, were selected as the control group (group D). RESULTS: During a mean follow-up period of 24 +/- 7.2 months, the recurrences of AF and atrial flutter in group B (42%) were significantly lower than those in group A (78%, p < 0.001), group C (92%, p < 0.001) and group D (92%, p < 0.001). CONCLUSIONS: The creation of a complete bi-directional conduction block at the inferior vena cava-tricuspid annulus isthmus, plus flecainide administration, reduces the recurrences of both AF and atrial flutter in patients with class IC atrial flutter. Moreover, the early response to flecainide is safe and reliable in identifying patients who may benefit from this therapy.