Botulinum Neurotoxins: Mechanism of Action.

Botulinum neurotoxins (BoNTs) are a growing family of bacterial protein toxins that cause botulism, a rare but often fatal animal and human disease. They are the most potent toxins known owing to their molecular architecture, which underlies their mechanism of action. BoNTs target peripheral nerve terminals by a unique mode of binding and enter into their cytosol where they cleave SNARE proteins, thus inhibiting the neurotransmitter release. The specificity and rapidity of binding, which limits the anatomical area of its neuroparalytic action, and its reversible action make BoNT a valuable pharmaceutical to treat neurological and non-neurological diseases determined by hyperactivity of cholinergic nerve terminals. This review reports the progress on our understanding of how BoNTs cause nerve paralysis highlighting the different steps of their molecular mechanism of action as key aspects to explain their extreme toxicity but also their unique pharmacological properties.

First operation of the SASE1 undulator system of the European X-ray Free-Electron Laser.

The European XFEL comprises three undulator systems. All of the systems use standardized mechanical, magnetic and control components. The key elements such as undulators, phase shifters and quadrupole movers as well as their controls are described, with special emphasis on the SASE1 undulator system, which was the first to become operational and has been lasing since May 2017. The role of these systems for the commissioning is outlined with special emphasis on beam-based alignment, which was important to achieve first lasing. Radiation damage was observed. The exposure doses were measured with the online radiation dosimetry system. Countermeasures and latest results are reported, which are important for a high-duty-cycle machine such as the European XFEL.

Single-crystal X-ray diffraction and resonant X-ray magnetic scattering at helium-3 temperatures in high magnetic fields at beamline P09 at PETRA III.

The resonant scattering and diffraction beamline P09 at PETRA III at DESY is equipped with a 14 T vertical field split-pair magnet. A helium-3 refrigerator is available that can be fitted inside the magnet's variable-temperature insert. Here the results of a series of experiments aimed at determining the beam conditions permitting operations with the He-3 insert are presented. By measuring the tetragonal-to-orthorhombic phase transition occurring at 2.1 K in the Jahn-Teller compound TmVO4, it is found that the photon flux at P09 must be attenuated down to 1.5 × 10(9) photons s(-1) for the sample to remain at temperatures below 800 mK. Despite such a reduction of the incident flux and the subsequent use of a Cu(111) analyzer, the resonant X-ray magnetic scattering signal at the Tm LIII absorption edge associated with the spin-density wave in TmNi2B2C below 1.5 K is intense enough to permit a complete study in magnetic field and at sub-Kelvin temperatures to be carried out.

Botulinum toxin infusion into the mesenteric artery has selective action on peristalsis in a rat model: experimental research.

OBJECTIVE: Botulinum toxin type A (BoNT/A) reversibly blocks neurotransmission at voluntary and autonomic cholinergic nerve terminals, inducing paralysis. The aim of this study was to block panenteric peristalsis in rats through BoNT/A administration into the superior mesenteric artery (SMA) and to understand whether the toxin's action is selectively restricted to the perfused territory. MATERIALS AND METHODS: Rats were infused through a 0.25-mm surgically inserted SMA catheter with different doses of BoNT/A (10 U, 20 U, 40 U BOTOX®, Allergan Inc.) or with saline for 24 h. Animals were free to move on an unrestricted diet. As a sign of bowel peristalsis impairment, body weight and oral/water intake were collected for 15 days. Statistical analysis was conducted with nonlinear mixed effects models to study the variation over time of the response variables. In three 40 U-treated rats, the selectivity of the intra-arterial delivered toxin action was studied by examining bowel and voluntary muscle samples and checking the presence of BoNT/A-cleaved SNAP-25 (the smoking gun of the toxin action) using the Immunofluorescence (IF) method through a specific antibody recognition. RESULTS: While control rats exhibited an increasing body weight, treated rats showed an initial dose-dependent weight reduction (p<0.001 control vs. treated) with recovery after Day 11 for 10 and 20 U-treated rats. Food and water intake over time showed significantly different half-saturation constants with rats treated with higher doses who reached half of the maximum achievable in a greater number of days (p<0.0001 control vs. treated rats). BoNT/A-cleaved SNAP-25 was identified in bowel wall NMJs and not in voluntary muscles, demonstrating the remarkable selectivity of arterially infused BoNT/A. CONCLUSIONS: Blockade of intestinal peristalsis, can be induced in rats by slow infusion of BoNT/A into the SMA. The effect is long-lasting, dose-dependent and selective. BoNT/A delivery into the SMA through a percutaneous catheter could prove clinically useful in the treatment of entero-atmospheric fistula by temporarily reducing fistula output.

Anisotropic Dirac fermions in a Bi square net of SrMnBi2.

We report the observation of highly anisotropic Dirac fermions in a Bi square net of SrMnBi(2), based on a first-principles calculation, angle-resolved photoemission spectroscopy, and quantum oscillations for high-quality single crystals. We found that the Dirac dispersion is generally induced in the (SrBi)(+) layer containing a double-sized Bi square net. In contrast to the commonly observed isotropic Dirac cone, the Dirac cone in SrMnBi(2) is highly anisotropic with a large momentum-dependent disparity of Fermi velocities of ~8. These findings demonstrate that a Bi square net, a common building block of various layered pnictides, provides a new platform that hosts highly anisotropic Dirac fermions.

Machine learning methods applied to audit of surgical margins after curative surgery for head and neck cancer.

Most surgical specialties have attempted to address concerns about the unfair comparison of outcomes by 'risk-adjusting' data to benchmark specialty-specific outcomes that are indicative of quality of care. We explore the ability to predict for positive margin status so that effective benchmarking that will account for complexity of case mix is possible. A dataset of care episodes recorded as a clinical audit of margin status after surgery for head and neck squamous cell carcinoma (n=1316) was analysed within the Waikato Environment for Knowledge Analyisis (WEKA) machine learning programme. The outcome was a classification model that can predict for positivity of tumour margins (defined as less than 1mm) using data on preoperative demographics, operations, functional status, and tumour stage. Positive resection margins of less than 1mm were common, and varied considerably between treatment units (19%-29%). Four algorithms were compared to attempt to risk-adjust for case complexity. The 'champion' model was a Naïve Bayes classifier (AUROC 0.72) that suggested acceptable discrimination. Calibration was good (Hosmer-Lemershow goodness-of-fit test p=0.9). Adjusted positive margin rates are presented on a funnel plot. Subspecialty groups within oral and maxillofacial surgery are seeking metrics that will allow for meaningful comparison of the quality of care delivered by surgical units in the UK. To enable metrics to be effective, we argue that they can be modelled so that meaningful benchmarking, which takes account of variation in complexity of patient need or care, is possible.

Magnetic breakdown in the electron-doped cuprate superconductor Nd(2-x)Ce(x)CuO4: the reconstructed Fermi surface survives in the strongly overdoped regime.

We report on semiclassical angle-dependent magnetoresistance oscillations and the Shubnikov-de Haas effect in the electron-overdoped cuprate superconductor Nd(2-x)CexCuO4. Our data provide convincing evidence for magnetic breakdown in the system. This shows that a reconstructed multiply connected Fermi surface persists, at least at strong magnetic fields, up to the highest doping level of the superconducting regime.

A phase I study of panobinostat and ruxolitinib in patients with primary myelofibrosis (PMF) and post--polycythemia vera/essential thrombocythemia myelofibrosis (post--PV/ET MF).

Ruxolitinib, a selective JAK1/JAK2 inhibitor, is the current first line therapy for myelofibrosis (MF), which reduces symptomatology and splenomegaly, but does not clearly modify disease course. Panobinostat, a histone deacetylase inhibitor, was shown to be safe and tolerable in phase I and II trials and demonstrated clinical activity in approximately a third of treated patients. Combination therapy of ruxolitinib and panobinostat showed synergistic activity in a preclinical MF model, which prompted clinical evaluation of this combination in both ruxolitinib naïve and treated MF patients. Herein, we report the results of an investigator-initiated, dose escalation, phase I trial of ruxolitinib and panobinostat in 15 patients with primary MF and post-polycythemia vera/essential thrombocythemia MF. This combination treatment proved to be safe and tolerable without dose limiting thrombocytopenia and a maximum tolerated dose of both agents in combination was not determined. The majority of patients maintained stable disease with this combination treatment and 40 % attained a clinical improvement (spleen n = 5, anemia n = 1) by modified IWG-MRT at the end of 6 cycles. This is one of the first attempts of rationally designed, JAK inhibitor-based, combination therapy studies and exemplifies the feasibility of such an approach in patients with advanced MF.

Absence of interaction between rivaroxaban, tacrolimus and everolimus in renal transplant recipients with deep vein thrombosis or atrial fibrillation.

No data are available on rivaroxaban use in renal transplant recipients and on its surmised interaction with immunosuppressants. The aim was to investigate potential interactions between rivaroxaban and immunosuppressants in this setting. Renal transplant recipients with a stable renal function treated with rivaroxaban and tacrolimus with or without everolimus were investigated. All drugs and creatinine concentrations were determined daily for 2 weeks after the start of anticoagulation. Blood samples were drawn at 8.00 am and 3-4 h later for trough and peak concentrations, respectively. Bleeding and thrombotic events were recorded during a minimum follow-up of 6 months. In 8 renal transplant patients, rivaroxaban levels showed a predictable pharmacokinetic trend, both at Ctrough (30-61 µg/L) and at Cpeak (143-449 µg/L), with limited variability in the 25th-75th percentile range. Tacrolimus (Ctrough 3-13 µg/L; Cpeak 3-16 µg/L), everolimus (Ctrough 3-11 µg/L; Cpeak 5-17 µg/L) and creatinine concentrations were stable as well. Immunosuppressors variability before and after rivaroxaban were 30% and 30% for tacrolimus, 27% and 29% for everolimus, respectively, as well as 14% and 3% for creatinine. For rivaroxaban monitoring, the reference change value better performed in identifying significant variations of its concentration. No patient had bleeding or thrombotic events, worsening of renal graft function, and signs of immunosuppressants toxicity during a mean follow-up of 23 (9-28) months. In conclusion, rivaroxaban does not seem to interact with tacrolimus and everolimus in renal transplant recipients. Both anticoagulant and immunosuppressive effects seem warranted, without major bleeding complications and effect on the graft function.

[Work integration of impaired workers in a type-B social cooperative]. / L'inserimento professionale di lavoratori disabili in una cooperativa sociale di tipo B.

This research aims to evaluate job occupation results of impaired workers in a type-B social cooperative, taking into consideration not only specific occupational risks' analysis and assessment, but also organisational, relational and psycho-social matters essential for their stable job occupation. The impaired workers involved were all those hired by a type-B social cooperative from Jan 1999 until Dec 2007, ie. 16 workers (M 8, F 8), equal to 40% of employees' total number. Every impaired worker has been submitted to preventive health surveillance in order to evaluate the degree of disability and residual job ability in relation to the job tasks suitable for him/her. In order to find available tasks which can be performed by disadvantaged workers, the personnel chart has been analyzed, and 10 of the 16 workers (equal to 62.5%) have been considered fit for the specific task without limitations. The other 6 (37.5%) have been considered capable of the specific task with limitations and/or prescriptions, and for 2 of them (12.5%) a tutorial supervision prescription was also necessary. Among those 6 workers with limitations and/or prescriptions, 4 were psychologically impaired (67%) and 2 were physically impaired (37%). The situation of these 16 impaired workers has been periodically verified and followed up for 8 years. Not only have the fifteen workers continued to perform the task initially considered suitable for their health status, but for some of them (5 workers), an increase in job performance, in both complexity and shift duration, has been observed. Moreover, with the only exception of a psychologically impaired worker who did alternate between good comfort times and occasional disease acute phases, all other workers have shown good and stable gains in psychological and physical health conditions, performing requested tasks not only with efficiency, but also with commitment and motivation. All workers have shown a remarkable improvement in their ability to form relationships, mainly within the work environment amongst colleagues and supervisors, but also in a social and family environment. A special mention is deserved in the case of the only worker hired in our research who left the cooperative after many years of work activity where, after having attended specific professional courses, steadily and successfully joined a company still in the social field but not exclusively dedicated to impaired workers. It may be observed that when one faces the work integration of impaired workers, the usual risk evaluation processes cannot be enough for the reason that these workers, due to their 'disability', find themselves in hypersusceptible conditions in respect to occupational risk factors which are generally acceptable for the other workers. In risk assessment it is therefore necessary to perform an accurate and all-round study in every aspect of the job duty, even around those considered irrelevant which, as a result, may show to be unsuitable to the worker's health status or might alter his/her often precarious psychological-physical condition. In conclusion, in the risk assessment process used prior to the work integration of impaired workers considered by our research, the organisational, relational and psycho-social aspects of work activity have often played a primary role in respect to traditional risk factors usually monitored and evaluated.

Variant Bernard-Soulier syndrome type bolzano. A congenital bleeding disorder due to a structural and functional abnormality of the platelet glycoprotein Ib-IX complex.

We have studied a patient with a congenital bleeding disorder and phenotypic manifestations typical of Bernard-Soulier syndrome, including giant platelets with absent ristocetin-induced von Willebrand factor binding. Two monoclonal antibodies reacting with distinct epitopes in the amino-terminal domain of the alpha-chain of glycoprotein (GP) Ib were used to estimate the number of GP Ib molecules on the platelet membrane. In the patient, binding of one antibody (LJ-Ib10) was approximately 50% of normal, while binding of the other (LJ-Ib1) was absent. Binding of both antibodies was reduced to approximately 50% of normal in the mother and one sister of the propositus, and their platelets exhibited approximately 70% of normal von Willebrand factor binding. Immunoblotting studies confirmed the presence of GP Ib alpha, as well as GP IX, in patient platelets. Antibody LJ-Ib10, but not LJ-Ib1, could immunoprecipitate the patient's GP Ib alpha from surface-labeled proteins. Thus, platelets from the propositus contained a structurally and functionally altered GP Ib-IX complex lacking a specific antibody epitope and the ability to bind von Willebrand factor. In contrast, the binding of human alpha-thrombin to the patient's platelets was normal, and three classes of binding sites with high, intermediate, and low affinity could be detected. These studies define a distinct variant form of Bernard-Soulier syndrome and provide evidence, based on a naturally occurring mutant molecule, that the amino-terminal region of GP Ib alpha contains a von Willebrand factor-binding domain distinct from the high affinity thrombin-binding site. Use of different monoclonal antibodies with distinct epitope specificities appears to be essential for a correct identification of variant Bernard-Soulier syndrome.

Testicular metastasis as isolated recurrence after radical prostatectomy. A first case.

Prostate cancer synchronously or metachronously metastasizing to the testis is a rare finding. We herein report on the first case of a solitary testicular metastasis from an organ-confined prostate cancer, diagnosed 6 months after a radical prostatectomy, without evidence of previous or concomitant biochemical and local recurrence.

[Reactive anxiety crisis: a unique case of work injury]. / Crisi d'ansia reattiva: un caso particolare di infortunio sul lavoro.

The present study aims to describe a unique case in view of the disease diagnosed, the conditions of onset and the management by INAIL (Italian National Institute of Insurance for Injuries at Work and Occupational Diseases). A worker, after a verbal, animated dispute with some collegues, had an acute psychiatric agitation attack and went to the nearest emergency room, where he was investigated. No neuropsychiatric alteration was diagnosed, but based on anamnestic data, the physicians diagnosed an anxiety crisis reactive to work environment. A medical certificate for injury at work was produced and sent to the Insurance Board (INAIL). The worker was off work for 105 days diagnosed with a persistent anxious depressive syndrome, secondary to the traumatic event. INAIL reassessed the case later and confirmed only the first 30 days as due to work accident, while the following period was judged as related to affectivity disturbance due to common disease, not to work environment. Our case opens new perspective for the occupational physician in the assessment of ASD as work injury and of PTSD as professional disease, suggesting to give more attention to psychiatric health of workers.

Epistaxis after PDE-5 inhibitors misuse.

A 32-year-old male presented to our department for recurrent epistaxis during sexual intercourses. The patient controlled the bleeding each time with sponge packs and gauzes. During the consultation, he volunteered that the trigger for the epistaxis appeared to have been misuse of phosphodiesterase (PDE)-5 inhibitors, Viagra and Cialis. This first report of epistaxis after PDE-5 inhibitors in a young patient underline the possibility that in the next years the number of similar cases might increase due to the diffusion of PDE-5 inhibitor misuse in recreational settings.

Monoclonal gammopathy in human leishmaniasis.

A 64-year-old female with IgGk monoclonal components (total 45 g/l) and 30% abnormal plasma cells and plasmoblasts in bone marrow is reported. After the identification of leishmania in the bone marrow, liposomal amphotericin B was used and a progressive resolution of the gammopathy was documented.

Diagnosis and follow-up of thrombotic thrombocytopenic purpura by means of von Willebrand factor collagen binding assay.

Thrombotic thrombocytopenic purpura (TTP) is characterized by intravascular thrombosis leading to consumption of large or unusually large von Willebrand factor (VWF) multimers. The usefulness of VWF collagen binding (VWF:CB) assay was assessed in detecting the decrease/absence of large VWF multimers or the presence of abnormally large forms in patients with TTP. Nine patients with TTP were studied during the acute phase of the disorder and the absence of large VWF multimers was demonstrated by means of the VWF:CB assay. These findings were confirmed by VWF multimer pattern analysis; VWF:CB deficiency appeared to correlate with abnormalities in large VWF multimers. The diagnostic potency of VWF:CB was especially evident when the values were expressed as VWF:CB/VWF:Ag ratio. VWF:CB was also used during the follow-up of the disorder to document improvement or restoration of large VWF multimers. VWF:CB was able to detect the absence or decrease of large VWF multimers better than VWF ristocetin cofactor (VWF:RCo); in fact, VWF:CB was defective when large VWF multimers persisted to be decreased, in contrast with what observed with VWF:RCo. In conclusion, VWF:CB is a simple test that appears to be useful, together with clinical symptoms and reduced platelet count, for the diagnosis and follow-up of TTP.

The management of feto-maternal alloimmune thrombocytopenia: report of three cases.

We report herein three cases of severe fetal thrombocytopenia due to anti-human platelet antigen (HPA)- 1a maternal antibodies. The first and the third cases were diagnosed on the basis of previously affected siblings and treated successfully by maternal intravenous human immunoglobulins and corticosteroids. In the second case an unexpected neonatal thrombocytopenia was found after birth without previously affected siblings and treated subsequently with intravenous immunoglobulins. Our experience supports a switch from an invasive management, including early FBS (fetal blood sampling) and platelet transfusions, to a more cautious approach. Also in severe HPA-1a alloimmunization and in 'high risk' fetuses, prenatal maternal treatment could be performed, without previous FBS, only on the basis of a risk score defined by sibling history and parents' genotypes.

[Asthenopia and work at video display terminals: study of 191 workers exposed to the risk by administration of a standardized questionnaire and ophthalmologic evaluation]. / Astenopia e lavoro al videoterminale: studio di una popolazione di 191 lavoratori esposti al rischio mediante somministrazione di questionario anamnestico mirato e valutazione oftalmologica.

VDT (Visual Display Terminals) are commonly used in a wide range of occupational fields. Over the last ten years a number of studies have shown that ocular symptoms are the form of discomfort most frequently experienced by subjects who work at VDT. The symptoms as a whole characterize a complex syndrome named "asthenopia" and have been seen as a consequence of prolonged, fixed and closely oriented vision. In our study we have evaluated data derived from a standardized questionnaire (a series of questions elaborated and promoted by the Italian Society of Occupational Medicine and Industrial Hygiene). It was administered to a group of 191 workers who utilise VDT for more than 20 hours each week. We also took into consideration the results of ophthalmologic medical examinations performed on this particular group of workers. Prevalence of occupational asthenopia we found to be lower in this group than in the case of other reported investigations, though it proved to be higher in the case of female subjects. According to the Literature, symptoms intensity is related to the duration of weekly VDT use, there being no significant association with the number of years spent working at VDT. Our results show that prevalence of asthenopia was not significantly influenced by refractive alterations and this unexpected outcome might be explained by taking into account the small-size group of subjects affected by hypermetropic defects. It is well known that these are the most important factors in conditioning asthenopia. Our finding indicates the need for further research, which should include a larger group of VDT workers with refractive alterations and furthermore take into consideration environmental variables such as climate and illumination, since these are co-aetiological factors, known or suspected, of occupational asthenopia.

Nursing care as a predictor of phlebitis related to insertion of a peripheral venous cannula in emergency departments: findings from a prospective study.

BACKGROUND: To date, few studies have investigated the occurrence of phlebitis related to insertion of a peripheral venous cannula (PVC) in an emergency department (ED). AIM: To describe the natural history of ED-inserted PVC site use; the occurrence and severity of PVC-related phlebitis; and associations with patient, PVC and nursing care factors. METHODS: A prospective study was undertaken of 1262 patients treated as urgent cases in EDs who remained in a medical unit for at least 24h. The first PVC inserted was observed daily until its removal; phlebitis was measured using the Visual Infusion Phlebitis Scale. Data on patient, PVC, nursing care and organizational variables were collected, and a time-to-event analysis was performed. FINDINGS: The prevalence of PVC-related phlebitis was 31%. The cumulative incidence (78/391) was almost 20% three days after insertion, and reached >50% (231/391) five days after insertion. Being in a specialized hospital [hazard ratio (HR) 0.583, 95% confidence interval (CI) 0.366-0.928] and receiving more nursing care (HR 0.988, 95% CI 0.983-0.993) were protective against PVC-related phlebitis at all time points. Missed nursing care increased the incidence of PVC-related phlebitis by approximately 4% (HR 1.038, 95% CI 1.001-1.077). CONCLUSIONS: Missed nursing care and expertise of the nurses caring for the patient after PVC insertion affected the incidence of phlebitis; receiving more nursing care and being in a specialized hospital were associated with lower risk of PVC-related phlebitis. These are modifiable risk factors of phlebitis, suggesting areas for intervention at both hospital and unit level.

Role of pharmacologic rehabilitation in the recovery of sexual function following radical prostatectomy.

AIM: The aim of the present study is to evaluate the role of pharmacological postoperative sexual rehabilitation in the recovery of erectile function following radical retropubic prostatectomy. METHODS: Following radical retropubic prostatectomy 113 patients were divided into 2 groups: 77 (group 1) underwent pharmacologic rehabilitation with intracavernous PGE1 starting with 5 mg once or twice weekly beginning 1 month after surgery, followed by oral sildenafil 50-100 mg twice a week after recovery of spontaneous erections, while 36 (group 2) acted as controls. The 2 groups were homogeneous for age and preoperative IIEF5 score, while nerve-sparing techniques were used more frequently in group 1. RESULTS: With 1 year follow-up 42% of group 1 patients have recovered sexual function, versus 8% of group 2 (P < 0.001). The mean recovery time was 7 months, and 56% of rehabilitated patients with bilateral preservation of the neurovascular bundles recovered sexual function, compared to 37.5% of those with unilateral preservation and 28.5% of those operated with non nerve-sparing technique. Intracavernous PGE1 caused pain in 27% of cases. CONCLUSIONS: Pharmacologic rehabilitation significantly impacts on the recovery of sexual function following radical prostatectomy, and the optimal treatment schedule is still to be defined.