Attenuation Coefficient Estimation of Normal Placentas

Attenuation coefficient estimation has the potential to be a useful tool for placental tissue characterization. A current challenge is the presence of inhomogeneities in biological tissue that result in a large variance in the attenuation coefficient estimate (ACE), restricting its clinical utility. In this work, we propose a new Attenuation Estimation Region Of Interest (AEROI) selection method for computing the ACE based on the (i) envelope signal-to-noise ratio deviation and (ii) coefficient of variation of the transmit pulse bandwidth. The method was first validated on a tissue-mimicking phantom, for which an 18%–21% reduction in the standard deviation of ACE and a 14%–24% reduction in the ACE error, expressed as a percentage of reported ACE, were obtained. A study on 59 post-delivery clinically normal placentas was then performed. The proposed AEROI selection method reduced the intra-subject standard deviation of ACE from 0.72 to 0.39 dB/cm/MHz. The measured ACE of 59 placentas was 0.77 ± 0.37 dB/cm/MHz, which establishes a baseline for future studies on placental tissue characterization.     

Synthesis of diagnostic quality cancer pathology images by generative adversarial networks

Deep learning-based computer vision methods have recently made remarkable breakthroughs in the analysis and classification of cancer pathology images. However, there has been relatively little investigation of the utility of deep neural networks to synthesize medical images. In this study, we evaluated the efficacy of generative adversarial networks to synthesize high-resolution pathology images of 10 histological types of cancer, including five cancer types from The Cancer Genome Atlas and the five major histological subtypes of ovarian carcinoma. The quality of these images was assessed using a comprehensive survey of board-certified pathologists (n = 9) and pathology trainees (n = 6). Our results show that the real and synthetic images are classified by histotype with comparable accuracies and the synthetic images are visually indistinguishable from real images. Furthermore, we trained deep convolutional neural networks to diagnose the different cancer types and determined that the synthetic images perform as well as additional real images when used to supplement a small training set. These findings have important applications in proficiency testing of medical practitioners and quality assurance in clinical laboratories. Furthermore, training of computer-aided diagnostic systems can benefit from synthetic images where labeled datasets are limited (e.g. rare cancers). We have created a publicly available website where clinicians and researchers can attempt questions from the image survey ( http://gan.aimlab.ca/ ). © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Prevalence and Assessment of Malnutrition Risk among Hospitalized Children in Romania

Malnutrition is a prevalent condition in hospitalized children. Our aims were to evaluate the nutritional state and to validate the STRONGkids risk assessment tool in a hospitalized paediatric population in Romania. This is a prospective single-centre study in a tertiary teaching hospital in Romania (May 2011-January 2012). We calculated the STRONGkids score and measured the children''s height and weight. Standard deviation <-2 for weight-for-height and height-for-age was considered to indicate acute or chronic malnutrition respectively. Two hundred seventy-one children were included, with median age of 5.2 years and median hospital stay of 2.01 days. Prevalence of malnutrition and severe malnutrition was 37% and 15% respectively. Using the STRONGkids screening tool, 58% of the children were found at risk of malnutrition (24% were at high risk). The kappa coefficient of agreement between STRONGkids and WHO malnutrition classification was 0.61. When a low serum protein level was used in upgrading STRONGkids risk category, kappa increased significantly to 0.71 (p=0.001). A modified STRONGkids score, incorporating total serum protein levels, performs well in predicting malnutrition in hospitalized paediatric population in Romania.Key words: Child, Malnutrition, Serum proteins, Romania     

Human papillomavirus infection in the oromaxillofacial area: Clinical anatomy and histological considerations

Clinical manifestations of human papillomavirus (HPV) infection in the head and neck can range from benign lesions, which are the most frequent, to malignant lesions. The prevalence of head and neck cancer is increasing, despite currently decreasing trends in known risk factors such as smoking and alcohol use. A new patient profile has appeared in recent practice: most frequently a middle‐aged male patient who does not smoke or drink alcohol, is sexually active (possibly having multiple partners), and presents with oral or cervicofacial lesions requiring diagnosis and treatment. Another risk factor that should be considered in these patients is HPV infection. The association of oral potentially malignant disorders (OPMD) with HPV is a challenge for the medical practitioner. The gold standard for diagnosis is histopathological examination, which can also yield evidence suggesting HPV infection. Determination of the viral genotype provides additional data for assessing the oncological risk of an HPV infection. Treatment of these patients is aimed at removing the lesions, in association or not with antiviral treatment and recurrence control. Clin. Anat. 28:1002–1007, 2015. © 2015 Wiley Periodicals, Inc.     

Pseudomembranous aspergillus tracheobronchitis superimposed on post-tuberculosis tracheal stenosis

Pseudomembranous aspergillus tracheobronchitis superimposed on post-tuberculosis tracheal stenosis has not been previously reported. In the patient described in this case report, the airway obstruction was worsened by aspergillus infection which responded to antifungal therapy and debridement of pseudomembranous tissues by rigid bronchoscopic procedures. A silicone stent was successfully placed in the trachea to restore airway patency when there was no more evidence of tracheobronchial aspergillosis. This case raises the questions of whether, how and when to restore airway patency in patients with tracheal stenosis and concurrent aspergillus tracheobronchitis.     

Opioid receptor blockade prevents exercise-associated autonomic failure in humans

Hypoglycemia and exercise both induce the release of β-endorphin, which plays an important role in the modulation of the autonomic response during subsequent events. Because opioid receptor (OR) blockade during antecedent hypoglycemia has been shown to prevent hypoglycemia-associated autonomic failure, we hypothesized that OR blockade during exercise would prevent exercise-associated autonomic failure (EAAF). We studied 8 healthy subjects on 2 consecutive days, each of whom participated in three different studies in random order. The protocol on day 1 involved one of the following: 1) two 90-min hyperinsulinemic-euglycemic clamps plus naloxone infusion (control); 2) two 90-min hyperinsulinemic-euglycemic clamps with exercise at 60% Vo(2max), plus naloxone infusion (N+); or 3) same protocol as in the N+ group, but with saline infusion only (N-). On day 2, all were studied with stepped hyperinsulinemic-hypoglycemic clamps, using hormone concentrations and glucose turnover as indicators of hypoglycemia counterregulation. Compared with control, N- studies resulted in significantly blunted epinephrine and norepinephrine responses to subsequent hypoglycemia. Conversely, the N+ group exhibited unimpaired hypoglycemia counterregulation, characterized by appropriate increases in epinephrine, norepinephrine, and endogenous glucose production. Thus, OR blockade with naloxone during antecedent exercise prevents the development of acute EAAF by improving the catecholamine responses and by restoring endogenous glucose production.