Comparative Analysis of Postoperative Complications of Sentinel Node Identification Using the SentiMag® Method and the Use of a Radiotracer in Patients with Breast Cancer

(1) Background: The purpose of the study was a retrospective, comparative assessment of complications of the surgical sentinel node biopsy (SNB) procedure in breast cancer using the radiotracer method and the SentiMag^® method on groups of patients after 3.5 years of use. (2) Methods: The material was a group of 345 patients with primary surgical breast cancer who underwent the SNB procedure with the use of a radiotracer in combination with wide local excision (WLE), simple amputation (SA) with SNB and an independent SNB procedure in the period from May 2018 to January 2021 in the Department of Oncological Surgery. Of the patients who were monitored in the Hospital Outpatient Clinic, 300 were enrolled. The analyzed group was compared in terms of the occurrence of the same complications with the group of 303 patients also operated on in our center in the period from January 2014 to September 2017, in which SN identification was performed using the SentiMag^® method. (3) Results: The most common complications found were sensation disorders in the arm, which occurred in 16 (14.1%) patients using the radiotracer method, SentiMag^®-11 (9.9%). By comparing the complication rate between the methods with the radiotracer (n = 300) and SentiMag^® (n = 303), no significant differences were found. (4) Conclusions: Sentinel node (SN) identification using the radiotracer method and the SentiMag^® method are comparable diagnostic methods in breast cancer, with a low risk of complications.     

The construction of the Split Sleep Questionnaire on sleep habits during the COVID-19 pandemic in the general population

AimTo construct a single-format questionnaire on sleep habits and mood before and during the COVID-19 pandemic in the general population.MethodsWe constructed the Split Sleep Questionnaire (SSQ) after a literature search of sleep, mood, and lifestyle questionnaires, and after a group of sleep medicine experts proposed and assessed questionnaire items as relevant/irrelevant. The study was performed during 2021 in 326 respondents distributed equally in all age categories. Respondents filled out the SSQ, the Pittsburgh Sleep Quality Index (PSQI), and State Trait Anxiety Inventory (STAI), and kept a seven-day sleep diary.ResultsWorkday and work-free day bedtime during the COVID-19 pandemic assessed with SSQ were comparable to the sleep diary assessment (P = 0.632 and P = 0.203, respectively), as was the workday waketime (P = 0.139). Work-free day waketime was significantly later than assessed in sleep diary (8:19 ± 1:52 vs 7:45 ± 1:20; P < 0.001). No difference in sleep latency was found between the SSQ and PSQI (P = 0.066). Cronbach alpha for Sleep Habits section was 0.819, and 0.89 for Mood section. Test-retest reliability ranged from 0.45 (P = 0.036) for work-free day bedtime during the pandemic to 0.779 (P < 0.001) for sleep latency before the pandemic.ConclusionThe SSQ provides a valid, reliable, and efficient screening tool for the assessment of sleep habits and associated factors in the general population during the COVID-19 pandemic.

The COVID-19 pandemic, along with its multiple adverse effects on various aspects of mental health, has significantly affected sleep. Sleep habits alterations and newly developed sleep disturbances during the COVID-19 pandemic may influence the overall well-being and health (1). Since the beginning of the pandemic, several studies reported a delay in bedtimes and waketimes, and an associated shift in chronotype toward eveningness (2-5).Even though actigraphy and sleep diaries provide a valid and reliable assessment of sleep habits (6,7), to achieve the highest reliability and validity, these methods require an assessment during seven consecutive days including weekends (8). Daily reporting may be perceived by the respondents as an additional burden (6,9), a limitation that may be overcome by the use of single-administration questionnaires (9,10). Since sleep disturbances recognized in the first pandemic outbreak remained stable during new waves of the COVID-19 pandemic (5), single-administration questionnaires may enable screening of large population groups and an extended assessment of sleep disturbances during the pandemic.So far, validated sleep questionnaires have most often aimed at sleep disorders or symptoms associated with sleep disorders (9). Studies commonly report the Pittsburgh sleep Quality Index (PSQI) (11), which provides data on sleep duration, sleep disturbances, and sleep latency during the previous month. However, PSQI reflects mainly sleep quality on workdays (12), while not collecting information on sleep habits on weekends. The Sleep Timing Questionnaire (STQ) has been developed as an alternative to the sleep diary for the healthy adult population, showing good reliability and validity (10). Still, although sleep habits are associated with mood (13), social media use (14-16), learning time in students (17-19), sports or exercise (20), and symptoms of insomnia (21), the STQ does not assess variables such as mood and lifestyle habits.Large studies objectively assessing sleep with wearable devices have recognized sleep timing and sleep duration to be modifiable risk factors for adverse mental health during the current pandemic (22). Young adults are especially at risk for increased mood disorder symptoms, higher levels of perceived stress, and more common alcohol use during the pandemic (23). Even though mood disorders are often reported in pandemic studies on sleep habits, mood itself has been less commonly measured and associated with sleep parameters (24). A review of the literature showed a transactional relationship between mood and emotion (25), indicating that mood is characterized by longer duration than emotion (26). Mood is often assessed with the Brief Mood Introspection Scale (27), the Profile of Mood States (28), or the Visual Analogue Mood Scale (29). A relevant aspect of mood measurement is a hierarchical structure with two broad dimensions in positive and negative affect, and multiple specific states (30). Commonly used mood assessment scales evaluate the basic negative mood of fear/anxiety, sadness/depression, and anger/hostility, as well as at least one positive mood. Therefore, it has been strongly recommended that mood researchers assess a broad range of both positive and negative emotions (30).Linking mood changes and lifestyle habits during the pandemic has been relevant in order to recognize possible predictors of mood changes, especially due to a reported increase in depression (31). Since sleep is often intertwined with mood and lifestyle changes (31), we assumed that a single-format questionnaire comprehensively assessing these variables and sleep may be applicable and timely.The aim of this study was to construct a single-format Split Sleep Questionnaire (SSQ) comprehensively assessing sleep habits, lifestyle habits, and mood changes, as well as to evaluate its reliability and validity in the general population. Sleep habits were validated by using standard instruments such as sleep diary, PSQI, and STAI questionnaires as the measures of construct validity. Additionally, we aimed to assess the psychometric properties of the Mood section and to explore the effects of the COVID-19 pandemic on sleep habits and mood alterations in the general population of Croatia.     

Voxel‐wise quantification of myocardial perfusion by cardiac magnetic resonance. Feasibility and methods comparison

The purpose of this study is to enable high spatial resolution voxel‐wise quantitative analysis of myocardial perfusion in dynamic contrast‐enhanced cardiovascular MR, in particular by finding the most favorable quantification algorithm in this context. Four deconvolution algorithms—Fermi function modeling, deconvolution using B‐spline basis, deconvolution using exponential basis, and autoregressive moving average modeling —were tested to calculate voxel‐wise perfusion estimates. The algorithms were developed on synthetic data and validated against a true gold‐standard using a hardware perfusion phantom. The accuracy of each method was assessed for different levels of spatial averaging and perfusion rate. Finally, voxel‐wise analysis was used to generate high resolution perfusion maps on real data acquired from five patients with suspected coronary artery disease and two healthy volunteers. On both synthetic and perfusion phantom data, the B‐spline method had the highest error in estimation of myocardial blood flow. The autoregressive moving average modeling and exponential methods gave accurate estimates of myocardial blood flow. The Fermi model was the most robust method to noise. Both simulations and maps in the patients and hardware phantom showed that voxel‐wise quantification of myocardium perfusion is feasible and can be used to detect abnormal regions. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.     

Atomic interactions of neonicotinoid agonists with AChBP: molecular recognition of the distinctive electronegative pharmacophore

Acetylcholine-binding proteins (AChBPs) from mollusks are suitable structural and functional surrogates of the nicotinic acetylcholine receptors when combined with transmembrane spans of the nicotinic receptor. These proteins assemble as a pentamer with identical ACh binding sites at the subunit interfaces and show ligand specificities resembling those of the nicotinic receptor for agonists and antagonists. A subset of ligands, termed the neonicotinoids, exhibit specificity for insect nicotinic receptors and selective toxicity as insecticides. AChBPs are of neither mammalian nor insect origin and exhibit a distinctive pattern of selectivity for the neonicotinoid ligands. We define here the binding orientation and determinants of differential molecular recognition for the neonicotinoids and classical nicotinoids by estimates of kinetic and equilibrium binding parameters and crystallographic analysis. Neonicotinoid complex formation is rapid and accompanied by quenching of the AChBP tryptophan fluorescence. Comparisons of the neonicotinoids imidacloprid and thiacloprid in the binding site from Aplysia californica AChBP at 2.48 and 1.94 A in resolution reveal a single conformation of the bound ligands with four of the five sites occupied in the pentameric crystal structure. The neonicotinoid electronegative pharmacophore is nestled in an inverted direction compared with the nicotinoid cationic functionality at the subunit interfacial binding pocket. Characteristic of several agonists, loop C largely envelops the ligand, positioning aromatic side chains to interact optimally with conjugated and hydrophobic regions of the neonicotinoid. This template defines the association of interacting amino acids and their energetic contributions to the distinctive interactions of neonicotinoids.     

Effect of statins on the development of renal dysfunction

Hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) decrease serum cholesterol. Dyslipidemia is believed to be associated with the development of renal dysfunction. It was postulated that statins may reduce the development of renal dysfunction. The effect of statin use on the development of renal dysfunction in 197,551 patients (Department of Veterans Affairs, Veterans Integrated Service Network 16 [VISN16] database) was examined. Of these patients, 29.5% (58,332 patients) were statin users and 70.5% (139,219 patients) were not. Development of renal dysfunction was defined as doubling of baseline creatinine or increase in serum creatinine > or =0.5 mg/dl from the first to last measurement with a minimum of 90 days in between. During 3.1 years of follow-up, 3.4% of patients developed renal dysfunction. After adjustment for demographics, diabetes mellitus, smoking, hypertension, and other medications (mainly angiotensin-converting enzyme inhibitors, calcium channel blockers, and aspirin), use of statins decreased the odds of developing renal dysfunction by 13% (odds ratio [OR] 0.87, 95% confidence interval [CI] 0.82 to 0.92, p <0.0001). The beneficial effect of statins appeared to be independent of the decrease in cholesterol. Other variables that affected the development of renal dysfunction were age (OR 1.04, 95% CI 1.03 to 1.04, p <0.0001), diabetes (OR 1.77, 95% CI 1.68 to 1.86, p <0.0001), hypertension (OR 1.11, 95% CI 1.02 to 1.2, p = 0.0153), and smoking (OR 1.12, 95% CI 1.02 to 1.24, p = 0.0244). In conclusion, statin use may retard the development of renal dysfunction. The beneficial effect of statins in preventing the development of renal dysfunction appears to be independent of their lipid-lowering effect.     

Freeze-frame inhibitor captures acetylcholinesterase in a unique conformation

The 1,3-dipolar cycloaddition reaction between unactivated azides and acetylenes proceeds exceedingly slowly at room temperature. However, considerable rate acceleration is observed when this reaction occurs inside the active center gorge of acetylcholinesterase (AChE) between certain azide and acetylene reactants, attached via methylene chains to specific inhibitor moieties selective for the active center and peripheral site of the enzyme. AChE catalyzes the formation of its own inhibitor in a highly selective fashion: only a single syn1-triazole regioisomer with defined substitution positions and linker distances is generated from a series of reagent combinations. Inhibition measurements revealed this syn1-triazole isomer to be the highest affinity reversible organic inhibitor of AChE with association rate constants near the diffusion limit. The corresponding anti1 isomer, not formed by the enzyme, proved to be a respectable but weaker inhibitor. The crystal structures of the syn1- and anti1-mouse AChE complexes at 2.45- to 2.65-A resolution reveal not only substantial binding contributions from the triazole moieties, but also that binding of the syn1 isomer induces large and unprecedented enzyme conformational changes not observed in the anti1 complex nor predicted from structures of the apoenzyme and complexes with the precursor reactants. Hence, the freeze-frame reaction offers both a strategically original approach for drug discovery and a means for kinetically controlled capture, as a high-affinity complex between the enzyme and its self-created inhibitor, of a highly reactive minor abundance conformer of a fluctuating protein template.     

Usefulness of dipyridamole stress echocardiography for predicting graft patency after coronary artery bypass grafting

Noninvasive techniques often provide controversial results in patients who have coronary artery bypass grafts (CABGs). Vasodilator stress echocardiography allows semi-simultaneous imaging of CABG flow and segmental left ventricular wall motion. To assess the comparative and additive value of regional flow and function for noninvasive evaluation of graft patency status, we evaluated 110 consecutive patients who underwent CABG and who were scheduled for coronary angiography. All patients underwent stress echocardiography with dipyridamole (0.84 mg/kg) and atropine (1 mg), including wall motion analysis by 2-dimensional echocardiography and Doppler evaluation of flow reserve of each CABG. Echocardiographic findings were compared with angiographic data. Four patients had inadequate acoustic windows. The remaining 106 patients had 226 grafts performed. Stress echocardiography showed 67% sensitivity, 91% specificity, and 71% accuracy for identification of 50% to 100% stenosis in the graft or in the recipient coronary vessel. There was a fair agreement with angiography (kappa coefficient 0.60). Identification of impaired coronary bypass flow reserve (i.e., <1.9 for internal mammary grafts and <1.6 for saphenous vein grafts) by Doppler had 91% sensitivity, 88% specificity, and 89% accuracy for graft stenosis. There was good agreement with angiographic findings (kappa 0.77). The combination of the 2 techniques achieved 93% sensitivity, 93% specificity, and 93% accuracy, showing a very good agreement with the patency status of the grafts as evaluated at angiography (kappa 0.85). The combined assessment of wall motion and flow reserve in patients who underwent CABG is feasible and provides an accurate estimate of graft patency status by increasing sensitivity of stress echocardiography and specificity of Doppler flow reserve.     

Image Quality in Real-Time Teleultrasound of Infant Hip Exam Over Low-Bandwidth Internet Links: a Transatlantic Feasibility Study

Evolution of communication systems, especially internet-based technologies, has probably affected Radiology more than any other medical specialty. Tremendous increase in internet bandwidth has enabled a true revolution in image transmission and easy remote viewing of the static images and real-time video stream. Previous reports of real-time telesonography, such as the ones developed for emergency situations and humanitarian work, rely on high compressions of images utilized by remote sonologist to guide and supervise the unexperienced examiner. We believe that remote sonology could be also utilized in teleultrasound exam of infant hip. We tested feasibility of a low-cost teleultrasound system for infant hip and performed data analysis on the transmitted and original images. Transmission of data was accomplished with Remote Ultrasound (RU), a software package specifically designed for teleultrasound transmission through limited internet bandwidth. While image analysis of image pairs revealed statistically significant loss of information, panel evaluation failed to recognize any clinical difference between the original saved and transmitted still images.