Effects of alfaxalone, propofol and isoflurane on cerebral blood flow and cerebrovascular reactivity to carbon dioxide in dogs: A pilot study.

Propofol total intravenous anesthesia is a common choice to anesthetize patients with increased intracranial pressure, reducing cerebral blood flow while maintaining cerebrovascular reactivity to CO2. Propofol and alfaxalone are commonly used for total intravenous anesthesia in dogs, but the effects of alfaxalone on cerebral blood flow and cerebrovascular reactivity to CO2 are unknown. Our hypothesis was that alfaxalone would not be significantly different to propofol, while isoflurane would increase cerebral blood flow and decrease cerebrovascular reactivity to CO2. Six healthy hound dogs were evaluated in this randomized crossover trial. Dogs were anesthetized with 7.5 mg/kg propofol, 3 mg/kg alfaxalone or 8 % sevoflurane, mechanically ventilated and maintained with propofol (400 µg/kg/min), alfaxalone (150 µg/kg/min) or 1.7 % end-tidal isoflurane, respectively, with one week washout between treatments. Cerebral blood flow and cerebrovascular reactivity to CO2 during hypercapnic and hypocapnic challenges were measured using arterial spin labelling and blood oxygen level-dependent magnetic resonance imaging sequences, respectively. Median (interquartile range, IQR) normocapnic cerebral blood flow was significantly lower (P = 0.016) with alfaxalone compared to isoflurane, in the whole brain 15.39 mL/min/100 g (14.90-19.90 mL/min/100 g) vs. 34.10 mL/min/100 g (33.35-43.17 mL/min/100 g), the grey matter 14.57 mL/min/100 g (13.66-18.72 mL/min/100 g) vs. 32.37 mL/min/100 g (31.03-42.99 mL/min/100 g), the caudal brain 15.47 mL/min/100 g (13.37-21.45 mL/min/100 g) vs. 36.85 mL/min/100 g (32.50-47.18 mL/min/100 g) and the temporal lobe grey matter 18.80 mL/min/100 g (15.89-20.84 mL/min/100 g) vs. 43.32 (36.07-43.58 mL/min/100 g). Median (IQR) hypocapnic cerebrovascular reactivity to CO2 was significantly higher (P = 0.016) for alfaxalone compared to isoflurane 8.85 %S/mm Hg (6.92-10.44 %S/mm Hg) vs. 3.90 %S/mm Hg (3.80-4.33 %S/mm Hg). Alfaxalone maintained lower cerebral blood flow and higher hypocapnic cerebrovascular reactivity to CO2 than isoflurane.

Corpses against science death: new Italian law titled 'Rules relating to the directives of one's body and tissues post-mortem for study, training, and scientific research purposes'.

The new Italian Law no. 10 of 2020, titled 'Rules relating to the directives of one's body and tissues post-mortem for study, training, and scientific research purposes' (10 February, 2020), has opened the doors to a new and clearer regimentation on body donation to science, according to the procedure already introduced by Law no. 219/2017 on the 'Rules relating to informed consent and advance directives of treatment'. The authors exposed some concerning regarding the application of the law, such as donation mistrust, also linked to our cultural heritage; the incomplete protection of minor and incompetent people; the complexity of an adequate information, which could undermine the informed consent; and finally, the fees overload for research institutes, with already exiguous budgets. Next, the authors analysed some positive aspects of the law and in primis the central role of corpses in scientifical knowledge and medical training. Moreover, a simple mechanism based on a conscious and pre-stated consent, registered in a database that follows European data protection Regulation, is discussed. Further, the procedure of the restitution of the bodies to their families, which represents a way to guarantee the relatives' commemoration, is also elucidated. In conclusion, the authors proposed a format of informed consent, to try a direct application of the law, thereby fastening the process of standardisation and centralisation of all the living wills. The authors optimistically investigated the opportunities offered by the law and encouraged a conscientious participation by citizens.

Author Correction: Forearc carbon sink reduces long-term volatile recycling into the mantle.

An Amendment to this paper has been published and can be accessed via a link at the top of the paper.

Author Correction: Forearc carbon sink reduces long-term volatile recycling into the mantle.

Change history: In this Article, the original affiliation 2 was not applicable and has been removed. In addition, in the Acknowledgements there was a statement missing and an error in a name. These errors have been corrected online.

Forearc carbon sink reduces long-term volatile recycling into the mantle.

Carbon and other volatiles in the form of gases, fluids or mineral phases are transported from Earth's surface into the mantle at convergent margins, where the oceanic crust subducts beneath the continental crust. The efficiency of this transfer has profound implications for the nature and scale of geochemical heterogeneities in Earth's deep mantle and shallow crustal reservoirs, as well as Earth's oxidation state. However, the proportions of volatiles released from the forearc and backarc are not well constrained compared to fluxes from the volcanic arc front. Here we use helium and carbon isotope data from deeply sourced springs along two cross-arc transects to show that about 91 per cent of carbon released from the slab and mantle beneath the Costa Rican forearc is sequestered within the crust by calcite deposition. Around an additional three per cent is incorporated into the biomass through microbial chemolithoautotrophy, whereby microbes assimilate inorganic carbon into biomass. We estimate that between 1.2 × 108 and 1.3 × 1010 moles of carbon dioxide per year are released from the slab beneath the forearc, and thus up to about 19 per cent less carbon is being transferred into Earth's deep mantle than previously estimated.

A topological look at human trabecular bone tissue.

Bone quality is affected by trabecular architecture at microscopic level. Various abnormalities of bone tissue lead to altered strength and to an increased susceptibility to fracture, such as Osteoporosis and Osteoarthritis, two major health burdens of our society. These are two complex musculoskeletal diseases that mainly concern bone tissue. In the last twenty years, there has been a growing interest in finding an appropriate topological model for the micro-architecture of trabecular bone tissue. In particular, we prove that these models involve general topological spaces. The appropriate notion to deal with is that of CW-complex.

Expected and actual adverse drug-drug interactions in elderly patients accessing the emergency department: data from the ANCESTRAL-ED study.

OBJECTIVE: This study was aimed at evaluating the frequency and describing the adverse drug-drug interactions (DDIs) recorded among elderly patients accessing the emergency department (ED). METHODS: Patients aged ≥65 years, accessing the ED of Pisa University Hospital (Italy) from 1 January 2015 to 31 December 2015 within the ANCESTRAL-ED program, were included in this study. 'Expected' DDIs were assessed using Thomson Micromedex®. Each ED admission (discharge diagnosis) consistent with the signs and symptoms of an expected DDI for each patient was classified as an 'actual' DDI. RESULTS: Throughout the study period, 3473 patients (3812 ED admissions, 58% females, mean age: 80.3) were recorded. The total number of expected DDIs was 12,578 (67 contraindicated; 3334 major; 8878 moderate; 299 minor) detected in 2147 (62%) patients. Overall 464 expected DDIs were found to be consistent with the ED admission in 194 patients (representing 9% of patients with expected DDIs). CONCLUSIONS: More than one half of elderly patients admitted to ED presented at least one expected DDI at the time of ED presentation. However, 9% of the expected DDIs were identified as actual DDIs, based on the consistency of the expected event with the ED discharge diagnosis.

Retrograde maxillary nerve perineural injection: A tomographic and anatomical evaluation of the infraorbital canal and evaluation of needle type and size in equine cadavers.

The aim of this study was to investigate a new approach for equine maxillary nerve blocks, which can facilitate several orofacial surgeries. Current techniques aim at the maxillary foramen and approach via the zygomatic arch, conferring the risk of injury to several delicate structures in the target area. To investigate the feasibility of a retrograde approach from the infraorbital foramen, an anatomic study of the infraorbital canal and its surrounding structures was performed on 13 cadaveric skulls using computed tomography and anatomical dissection. Measurements included canal length and volume, its conformation and relationship with the enclosed structures, and infraorbital foramen diameters. The technical approach to simulate the distribution of local anaesthetic within the infraorbital canal was further defined, including needle selection among seven different needles, evaluating ease of insertion, trauma to surrounding tissues and spread of contrast medium toward the target area. To validate the technique, two Tuohy needles were randomly inserted at 12 infraorbital foramina and 10 mL of contrast medium was injected. CT verified the spread of the solution and possible complications. Each canal had a serpentine-curved pathway. Anatomical dissections evidenced gaps between the infraorbital nerve, vessels and the infraorbital canal. The integrity of these structures had been preserved from the passage of the selected Tuohy needles. This study suggests a feasible approach to the maxillary nerve block within the infraorbital canal providing an appropriate needle selection and technique to limit complications.

Critical issues in radiology requests and reports.

PURPOSE: This study evaluated the appropriateness and accuracy of 500 radiology requests and their matched reports in order to identify recurring errors in both areas. MATERIALS AND METHODS: A randomly chosen sample consisting of 167 computed tomography (CT), 166 ultrasonography (US) and 167 radiographic examinations were collected and analysed according to national referral guidelines and to the principles of justification and optimisation (Law no. 187/2000). RESULTS: We identified a high rate of inappropriate requests (27.6%) and requests lacking a clinical question (22%). There was good precision in the anamnestic data (80.6%) and in the formulation of the diagnostic question (76.8%). Almost all requests were handwritten, and 12.5% lacked the referring physician's stamp and/or signature. No report mentioned the clinical information received or the equipment used. The use of contrast medium was always reported. Conclusions were reported in 9.8% of these reports. When further investigation would have been necessary, the radiologist omitted to report this in 60% of cases. CONCLUSIONS: Some important weaknesses emerged, especially regarding requests for radiological examinations (22% lacked the clinical question, 27.6% were inappropriate), potentially limiting the effectiveness of the diagnostic process and leading to negative effects on the correct risk management process. There emerges a need for better collaboration between clinicians and radiologists.

A method to calculate tissue impedance through a standard bipolar pacing lead.

UNLABELLED: The transthoracic impedance (T) and its variations may be estimated through the measurement of the electrical impedance between the can and the right ventricular coil of a defibrillation lead. This method may allow the monitoring of fluid overload before a heart failure attack. Aim of this study was to validate in vitro a method to calculate T in case of a standard bipolar pacing lead, by performing 3 measurements: standard unipolar impedance from the tip (Zuni-tip); unipolar impedance from the ring (Zuni-ring); standard bipolar impedance (Zbip). The formula we used is derived from the standard equivalent circuit of a pacing system: [Formula: see text] T represents the tissue impedance between the can and the electrodes of the lead. To validate the method we used a saline solution and 3 different pacing leads manufactured by Vitatron (Vitatron BV, Arnhem, The Netherlands): Impulse II (high impedance lead), Crystalline ActFix (screw-in lead), Brilliant S+ (VDD single-lead). The measured values of the saline solution impedance were compared to the values calculated through the formula. RESULTS: The calculated impedance of the solution, evaluated through the proposed formula, is reliable independently of the electrode used and highly correlated to the corresponding measured values (R>0.9). CONCLUSION: Tissue impedance may be calculated from standard unipolar and bipolar impedance measurements with a standard bipolar pacing lead.

Chest pain unit management of patients at low and not low-risk for coronary artery disease in the emergency department. A 5-year experience in the Florence area.

In this study, we screened a total of 6723 consecutive patients with chest pain and ECG non-diagnostic for acute myocardial infarction (AMI) on presentation to the emergency department (ED). The aim of the study was to avoid missed AMI, improve safe early discharge and reduce inappropriate coronary care unit (CCU) admission. Chest pain patients were triaged using a clinical chest pain score and managed in a chest pain unit (CPU). Patients with a low clinical chest pain score were considered at very 'low-risk' for cardiovascular events and discharged from the ED; patients with a high chest pain score were submitted to CPU management. Observation and titration of serum markers of myocardial injury were obtained up to 6 hours. Rest or stress myocardial scintigraphy (SPECT) was performed in patients > 40 years or with > or = 2 major coronary risk factors. Exercise Tolerance Test (ETT) or Stress-Echocardiogram (stress-Echo) were performed in younger patients or with < 2 coronary risk factor, or unable to exercise, respectively We discharged directly from the ED the majority of patients (4454; 66%): in this group there was only a 0.2% final diagnosis of coronary artery disease (CAD) at follow-up. The remaining 34% of patients, with non-diagnostic or normal ECG, were managed in the CPU. In this group, 1487 patients (representing 22% of the overall study group) were found positive for CAD, two-thirds because of delayed ECG or serum markers of myocardial injury, and one-third by Echo, SPECT or ETT. In conclusion, CPU based management allowed 22% early detection of myocardial ischaemia and 78% early discharge from the ED avoiding inappropriate CCU admission and optimizing the use of urgent angiography.

[Subarachnoid hemorrhage and the heart]. / ESA e cuore.

Electrocardiographic abnormalities had been reported, in patients with subarachnoid hemorrhage, with variable percentage from 2% to 91%, according to several studies. The most common changes are T wave inversion, ST segment elevation or depression, QT prolongation, U waves, atrial flutter and fibrillation, ventricular fibrillation, supraventricular tachycardia, premature atrial and ventricular contractions. These findings occur within the first forty-eight hours after the onset of the symptoms; they usually are benign and transient. In a small percentage of cases generally in severe ESA, the ECG changes are associated with ventricular asynergy, coronary vasospasm or subendocardic necrosis. The arrhythmias could be produced either by autonomic discharges to the heart, during increased sympathetic activity due to ESA, or by a damage of cerebral areas with arrhythmogenic capacity. The importance of ECG abnormalities towards mortality and morbidity in patients with ESA has not yet been cleared; however, a careful monitoring is recommended to prevent severe cardiac complications and to obtain an indirect, further evaluation of the neurologic pathology.

[Carcinogens in the urban environment of Italian cities: benzene and benzo(a)pyrenes]. / Cancerogeni nell'ambiente urbano delle città italiane: benzene e benzo(a)pirene.

In Italian urban areas air pollution from benzene and benzo(a)pyrene-B(a)P--is mostly caused by traffic. The concentration limits in the atmosphere fixed by Italian legislation up to December 31, 1998 expressed as annual means are 15 micrograms/m3 and 2.5 ng/m3 for benzene and B(a)P respectively and, starting from January 1, 1999, 10 micrograms/m3 and 1 ng/m3. In the city of Florence the concentrations detected and expressed as annual means of benzene and B(a)P in an area with heavy traffic (32.1 micrograms/m3 and 3.5 ng/m3), in a densely populated area (9.2 micrograms/m3 and 1.86 ng/m3), and in a city park (6.0 micrograms/m3 and 0.25 ng/m3), suggest a marked progressive reduction in the atmospheric levels of these chemicals with the distance from the main roads. The environmental data obtained from densely populated areas of a number of Italian cities (Firenze, Milano, Roma, Bologna, Bolzano, Pavia, Modena), the only ones that allow evaluation of the health risk, show benzene concentrations ranging from 6.0 to 11.3 micrograms/m3 and B(a)P levels, measured in heavy traffic areas, from 1.0 to 3.5 ng/m3 respectively (annual mean in 1996). The data obtained in the city of Florence show that the population is exposed weekly to average concentrations of 14.3 micrograms/m3 for benzene and 2.0 ng/m3 for B(a)P. These results suggest that, regarding benzene and B(a)P pollution, the situation in Florence is far from being critical but not such as to ensure that long-term exposure is without adverse effects.

[Validity of the V/Q index in the monitoring of critical patients]. / Validità dell'indice V/Q nel monitoraggio dei pazienti critici.

The Authors have controlled the validity of VQI to quantify pulmonary shunt (Qs/Qt). The survey involved (group A) patients who had undergone major surgery and (group B) patients hospitalized in ICU for cardiorespiratory failure. Four subgroups were identified in both the groups according to different values of SaO2. A good correlation, already described by Räsänen, was comproved in the groups and subgroups. However a progressive reduction of the coefficient of correlation from the lower to the higher values of SaO2 was noted. Finally the differences observed between group A and group B, are supposed to be dependent on a greater variability of haemoglobin, in the surgical group, in relation to the time of evaluation.

Pulsed Doppler verification of atrial contribution to ventricular filling in sequential pacing.

We have used pulsed Doppler to ascertain effective atrial contribution to ventricular filling in sequential pacemaker rhythm. The technique is particularly valuable when electrocardiographic evidence of atrial capture is uncertain.

Analgesic activity of carprofen on human experimental dental pain.

1. The effects of an orally administered single dose of placebo, acetylsalicyclic acid (ASA) and (d,1)-6-chloro-a-methyl carbazole-2-acetic acid (carprofen) have been evaluated on an experimental pain model by electrical stimulation of dental pulp in man. 2. ASA and carprofen showed a significant analgesic action, while placebo was ineffective. 3. Analgesic activity of ASA and carprofen was similar. The two drugs were ineffective in modifying the pain threshold; on the contrary, the tolerance to the strongest painful sensation was significantly increased.