Pulsed Doppler echocardiography in the diagnosis and estimation of severity of aortic insufficiency

Detection and estimation of the degree of chronic aortic insufficiency with pulsed Doppler echocardiography was attempted in 27 patients documented to have aortic insufficiency on aortography. Twenty-five patients had associated aortic stenosis or mitral valve disease, or both. A disturbed diastolic flow within the left ventricular outflow tract was recorded in all but one patient (Doppler sensitivity 96 percent). Aortic insufficiency was clinically undetected In three patients (clinical sensitivity 89 percent). In a small number of patients Doppler echocardiography also appeared to be highly specific for this disorder. The Doppler technique estimated the degree of aortic Insufficiency by assessing the distribution of diastolic flow within the outflow tract and the body of the left ventricle. A significant correlation between the Doppler method and the angiographic estimation of aortic insufficiency was found (r = 0.88, p < 0.01).     

The influence of excipients on physical and pharmaceutical properties of oral lyophilisates containing a pregabalin-acetaminophen combination

Objectives: The purpose of the study was to investigate and characterize the oral lyophilisates containing the pregabalin-acetaminophen drug combination and as xcipients mannitol with microcrystalline cellulose or hydroxypropyl methylcellulose, in order to conclude upon drug-excipient interactions and their stability implications, impact of excipients on drug release and on the physicochemical and mechanical properties of the pharmaceutical formulations.

Methods: The oral tablets were made by using a Christ freeze-dryer alpha 2–4-LSC lyophilizer, and evaluated for stability, drug-excipient compatibility and homogeneity of the prepared pharmaceutical formulations. The formulations were evaluated for in vivo absorption in rabbits by histopathological exams.

Results: FTIR and thermogravimetric analyses, DLS technique, SEM and NIR-CI studies confirmed the compatibility between compounds. From the determined physical and biochemical parameters of the formulations it was established that they are stable, homogeneous, and meet the conditions for orally disintegrating tablets.

Conclusion: In the case of the investigated pharmaceutical formulations the study evidenced the assembling through physical bonds between the excipients and the ‘codrug’ complex, which do not affect the release of the bioactive compounds.     

Highly Porous and Ultra-Lightweight Aero-Ga2O3: Enhancement of Photocatalytic Activity by Noble Metals

A new type of photocatalyst is proposed on the basis of aero-β-Ga₂O₃, which is a material constructed from a network of interconnected tetrapods with arms in the form of microtubes with nanometric walls. The aero-Ga₂O₃ material is obtained by annealing of aero-GaN fabricated by epitaxial growth on ZnO microtetrapods. The hybrid structures composed of aero-Ga₂O₃ functionalized with Au or Pt nanodots were tested for the photocatalytic degradation of methylene blue dye under UV or visible light illumination. The functionalization of aero-Ga₂O₃ with noble metals results in the enhancement of the photocatalytic performances of bare material, reaching the performances inherent to ZnO while gaining the advantage of the increased chemical stability. The mechanisms of enhancement of the photocatalytic properties by activating aero-Ga₂O₃ with noble metals are discussed to elucidate their potential for environmental applications.     

Nosocomial Outbreak of SARS-CoV-2 in a “Non-COVID-19” Hospital Ward: Virus Genome Sequencing as a Key Tool to Understand Cryptic Transmission

Dissemination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in healthcare institutions affects both patients and health-care workers (HCW), as well as the institutional capacity to provide essential health services. Here, we investigated an outbreak of SARS-CoV-2 in a “non-COVID-19” hospital ward unveiled by massive testing, which challenged the reconstruction of transmission chains. The contacts network during the 15-day period before the screening was investigated, and positive SARS-CoV-2 RNA samples were subjected to virus genome sequencing. Of the 245 tested individuals, 48 (21 patients and 27 HCWs) tested positive for SARS-CoV-2. HCWs were mostly asymptomatic, but the mortality among patients reached 57.1% (12/21). Phylogenetic reconstruction revealed that all cases were part of the same transmission chain. By combining contact tracing and genomic data, including analysis of emerging minor variants, we unveiled a scenario of silent SARS-CoV-2 dissemination, mostly driven by the close contact within the HCWs group and between HCWs and patients. This investigation triggered enhanced prevention and control measures, leading to more timely detection and containment of novel outbreaks. This study shows the benefit of combining genomic and epidemiological data for disclosing complex nosocomial outbreaks, and provides valuable data to prevent transmission of COVID-19 in healthcare facilities.     

Efficacité clinique et biologique du tocilizumab au cours de la maladie de Horton : à propos de trois observations et revue de la littérature

Introduction

Treatment of giant cell arteritis is based on prolonged corticosteroid therapy but adverse side effects are common especially in the elderly.

Case reports

We report three patients with giant cell vasculitis treated by tocilizumab, an interleukin-6 receptor antibody, owing to resistance or intolerance to corticosteroid therapy. A favorable outcome was rapidly observed both on clinical and biological data allowing a corticoid therapy sparing.

Conclusion

Tocilizumab is a promising treatment of giant cell arteritis but controlled trials are needed to confirm its efficacy.     

Navigated anterior cruciate ligament replacement: an experimental validation study

We wanted to test the following hypothesis: the location of the tibial and femoral ACL attachments measured by a navigation system differs from their actual anatomic location. A total of 10 gross specimens were studied. The standard navigated procedure was used. Metallic reference pins were implanted around the tibial and femoral ACL attachments and palpated with a navigated stylus. Their position was recorded in comparison with the same tibial or femoral reference point. All measurements were repeated with a caliper. Caliper and navigated measurements were compared with appropriate statistical tests at a 0.05 level of significance. There was a significant difference between caliper and navigated measurements at the tibia in absolute value (maximal range of 4 mm, mean difference about 2 mm), but the difference ratio was low (about 3%); there was no significant difference between caliper and navigated measurements at the femur. There was a strong correlation and a good agreement between caliper and navigated measurements. It is likely that these differences have few, if any, clinical relevance. We demonstrated that the navigation system used during the present study has the potential to enhance the precision of the intra-operative measurement of the tunnel placement during ACL replacement.     

Comparative reproducibility of the noninvasive ultrasound methods for the assessment of vascular function

The aim of this work was to assess the reproducibility of ultrasound parameters of vascular function, since these measurements are currently recommended by the guidelines for the evaluation of the cardiovascular risk. Twenty subjects (51 ± 17 years, 11 men) had vascular ultrasound (Aloka Prosound α10) performed by two observers, at the level of the right common carotid artery for assessment of intima-media thickness (IMT), “wall tracking”, and “wave-intensity analysis”, and at the level of the right brachial artery for the assessment of flow-mediated dilation (FMD). Wave intensity is a hemodynamic index, evaluating ventriculo-arterial interaction and can be measured in real time by a double-beam ultrasound technique through simultaneous recording of carotid arterial blood flow velocity and diameter. Carotido-femoral pulse wave velocity (PWV) was determined using the Complior method. Intra- and inter-observer reproducibility was assessed during a first session, when three consecutive acquisitions were made (first observer → second observer → first observer); repeatability was evaluated 1 week later (second observer). The most reproducible and repeatable parameters were PWV (intraobserver ±3.3%, interobserver ±2.6%, repeatability ±5.6%) and IMT (±3.7, ±4.3, ±4.9%, respectively). Intraobserver reproducibility for arterial stiffness and ventriculo-arterial coupling parameters was the highest for the beta index (±3.8%), and the lowest for the second systolic peak (±22.4%). Interobserver reproducibility and repeatability varied between very good for the wave speed (±5.5 and ±4.3%), and unsatisfactory for the negative area (±31.8 and ±38.6%). FMD had good reproducibility (intraobserver ±11.6%, interobserver ±8%, repeatability ±7%), whereas augmentation index had only satisfactory results (±17.8, ±8.4, ±23.8%, respectively). Only some parameters of vascular function have good reproducibility and repeatability, better or similar to other ultrasound methods and, therefore, these are ready to be used in routine clinical practice.     

Contrast-Enhanced Ultrasound Defines Vascularization Pattern of Hamartomatous Colonic Polyps in Peutz-Jeghers Syndrome

The hamartomatous polyps in Peutz-Jeghers syndrome may have malignant potential. To differentiate between hamartomatous and adenomas polyps, vascular characterization can be assessed using noninvasive procedures, such as contrast-enhanced ultrasound (CEUS). The neo-angiogenic characteristics of colorectal adenomas and carcinomas are expressed as an anarchic vascular pattern observed on CEUS. Using CEUS in a patient with Peutz-Jeghers syndrome, we describe for the first time the vascularization of a hamartomatous colonic polyp that exhibits a hierarchy branching pattern.