Raster-scanning optoacoustic mesoscopy biomarkers for atopic dermatitis skin lesions

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease worldwide. Its severity is assessed using scores that rely on visual observation of the affected body surface area, the morphology of the lesions and subjective symptoms, like pruritus or insomnia. Ideally, such scores should be complemented by objective and accurate measurements of disease severity to standardize disease scoring in routine care and clinical trials. Recently, it was shown that raster-scanning optoacoustic mesoscopy (RSOM) can provide detailed three-dimensional images of skin inflammation processes that capture the most relevant features of their pathology. Moreover, precise RSOM biomarkers of inflammation have been identified for psoriasis. However, the objectivity and validity of such biomarkers in repeated measurements have not yet been assessed for AD. Here, we report the results of a study on the repeatability of RSOM inflammation biomarkers in AD to estimate their precision. Optoacoustic imaging analysis revealed morphological inflammation biomarkers with precision well beyond standard clinical severity metrics. Our findings suggest that optoacoustic mesoscopy may be a good choice for quantitative evaluations of AD that are inaccessible by other methods. This could potentially enable the optimization of disease scoring and drug development.

Assessment Of Antibody Levels In A Population Vaccinated With Sputnik V

Objectives — The objective of our study was to assess humoral response in a population of health workers after vaccination with the first and second doses of Sputnik V. Methods — SARS-CoV-2 total antibodies (IgG and IgM) were measured, using the Centaur XPT autoanalyzer, Siemens®, in 530 serum samples taken from health workers in Buenos Aires vaccinated with Sputnik V. Results — After 21 days of the first dose application, 10 individuals (1.9%) presented antibody levels <1.0 (non-reactive), while 520 subjects (98.1%) responded with antibody values >1.0 (reactive). The results, obtained 21 days after the second dose, show that only 2 individuals (0.38%) had antibody levels <1.0 (non-reactive) and 528 (99.6%) responded with antibody values >1.0 (reactive). Conclusion — This study results implied that two doses of Sputnik V vaccine generated a proper antibody response in virtually the entire studied population.

Optoakustische Bildgebung – Licht rein, Schall raus?

Die optoakustische Bildgebung ist eine neuartige Bildgebungsmodalität, welche auf der Aufzeichnung und Verarbeitung von Ultraschallsignalen basiert, die im Gewebe durch Absorption von Laserlicht entstehen. Die Methode vereint guten, auf Lichtabsorption beruhenden Kontrast mit hoher Eindringtiefe und ermöglicht sowohl morphologische als auch molekulare und funktionelle Bildgebung. Sie kann mit oder ohne Kontrastmittel eingesetzt werden und ist frei von ionisierender Strahlung. Darüber hinaus ist die Technik skalierbar und kann somit zur makroskopischen, mesoskopischen und mikroskopischen Bildgebung verwendet werden.

In den letzten Jahren wurden eine Reihe verschiedener Systeme zur optoakustischen Bildgebung entwickelt und in vielfältigen Bereichen der präklinischen und klinischen Forschung eingesetzt. In der Dermatologie zeigten sich vielversprechende Anwendungsgebiete der Optoakustik insbesondere in der Untersuchung von Melanomen, Wächterlymphknoten und nicht-melanozytärem Hautkrebs sowie in der Charakterisierung von entzündlichen Hauterkrankungen.

In diesem Review sollen die technischen Grundlagen der optoakustischen Bildgebung erläutert sowie der derzeitige Stand der Forschung hinsichtlich Anwendungsbereiche makroskopischer, mesoskopischer und mikroskopischer optoakustischer Systeme beschrieben und diskutiert werden.

Non-invasive imaging in dermatology and the unique potential of raster-scan optoacoustic mesoscopy

In recent years, several non‐invasive imaging methods have been introduced to facilitate diagnostics and therapy monitoring in dermatology. The microscopic imaging methods are restricted in their penetration depth, while the mesoscopic methods probe deeper but provide only morphological, not functional, information. ‘Raster‐scan optoacoustic mesoscopy’ (RSOM), an emerging new imaging technique, combines deep penetration with contrast based on light absorption, which provides morphological, molecular and functional information. Here, we compare the capabilities and limitations of currently available dermatological imaging methods and highlight the principles and unique abilities of RSOM. We illustrate the clinical potential of RSOM, in particular for non‐invasive diagnosis and monitoring of inflammatory and oncological skin diseases.

Assessing nailfold microvascular structure with ultra-wideband raster-scan optoacoustic mesoscopy

Nailfold capillaroscopy, based on bright-field microscopy, is widely used to diagnose systemic sclerosis (SSc). However it cannot reveal information about venules and arterioles lying deep under the nailfold, nor can it provide detailed data about surface microvasculature when the skin around the nail is thick. These limitations reflect the fact that capillaroscopy is based on microscopy methods whose penetration depth is restricted to about 200 μm. We investigated whether ultra-wideband raster-scan optoacoustic mesoscopy (UWB-RSOM) can resolve small capillaries of the nailfold in healthy volunteers and compared the optoacoustic data to conventional capillaroscopy examinations. We quantified UWB-RSOM-resolved capillary density and capillary diameter as features that relate to SSc biomarkers, and we obtained the first three-dimensional, in vivo images of the deeper arterioles and venules. These results establish the potential of UWB-RSOM for analyzing SSc-relevant markers.

Association between self-perceived psychological stress and transitory ischaemic attack and minor stroke: A case-control study

INTRODUCTION

Stroke has a complex aetiopathogenesis influenced by numerous risk factors. There is growing interest in the study of the pathophysiological changes associated with stress and their potential relationship with cerebrovascular disease. The purpose of this paper is to assess the strength of association between exposure to stress and stroke.

METHODS

We conducted a case-control study (1:1) to compare exposure to stress in a group of patients with a history of a first transient ischaemic attack (TIA) or minor stroke and in a control group. Participants were asked a subjective question about their perception of stress in the previous months and completed the standardised Effort-Reward Imbalance (ERI) questionnaire. Logistic regression models were used for data analysis.

RESULTS

The study included data on 50 cases and 50 controls. There were no significant differences in demographic variables and economic, social, and employment status between cases and controls. Fifty percent of the cases reported moderate to severe stress, compared to 30% of controls (OR: 2.33; 95% CI: 1.02-5.30; P=.041). ERI questionnaire results found that greater effort at work (OR: 1.48; 95% CI: 1.19-1.83) and greater commitment is associated with stroke (OR: 1.34; 95% CI: 1.17-1.54), while higher reward constitutes a protective factor against the disease (OR: 0.71; 95% CI: 0.61-0.82).

CONCLUSIONS

There is a strong association between self-perceived psychological stress and TIA. The imbalance between effort and reward at work is also clearly related to TIA.

CT findings of the main pathological conditions associated with horseshoe kidneys

Horseshoe kidney (HSK) is the most common renal fusion anomaly, with a prevalence of 0.25% among the general population. It consists of kidney fusion across the midline. HSK can be present as an isolated condition in 30%, but there is a wide variety of associated abnormalities. The most frequent include ureteropelvic obstruction, lithiasis and infections. There is also a higher risk of kidney lesions in trauma and an increased incidence of malignancies. Awareness of embryology and anatomy is essential to assess and understand the complications affecting HSK. CT is an excellent method for identification of its main findings.

Synchronization of interconnected networks: the role of connector nodes

In this Letter we identify the general rules that determine the synchronization properties of interconnected networks. We study analytically, numerically, and experimentally how the degree of the nodes through which two networks are connected influences the ability of the whole system to synchronize. We show that connecting the high-degree (low-degree) nodes of each network turns out to be the most (least) effective strategy to achieve synchronization. We find the functional relation between synchronizability and size for a given network of networks, and report the existence of the optimal connector link weights for the different interconnection strategies. Finally, we perform an electronic experiment with two coupled star networks and conclude that the analytical results are indeed valid in the presence of noise and parameter mismatches.

Pulmonary vascular complications in portal hypertension and liver disease: a concise review

Chronic liver disease and/or portal hypertension may be associated with one of the two pulmonary vascular complications: portopulmonary hypertension and hepatopulmonary syndrome. These pulmonary vascular disorders are notoriously underdiagnosed; however, they have a substantial negative impact on survival and require special attention in order to understand their diagnostic approach and to select the best therapeutic options. Portopulmonary hypertension results from excessive vasoconstriction, vascular remodeling, and proliferative and thrombotic events within the pulmonary circulation that lead to progressive right ventricular failure and ultimately to death. On the other hand, abnormal intrapulmonary vascular dilations, profound hypoxemia, and a wide alveolar-arterial gradient are the hallmarks of the hepatopulmonary syndrome, resulting in difficult-to-treat hypoxemia. The aim of this review is to summarize the latest pathophysiologic concepts, diagnostic approach, therapy, and prognosis of portopulmonary hypertension and hepatopulmonary syndrome, as well as to discuss the role of liver transplantation as a definitive therapy in selected patients with these conditions.

MO-D-BRB-02: The Radiological Physics Center's Quality Audit Program: Where Can We Improve?

PURPOSE

To analyze the findings of the Radiological Physics Center's (RPC) QA audits of institutions participating in NCI sponsored clinical trials.

METHODS

The RPC has developed an extensive Quality Assurance (QA) program over the past 44 years. This program includes on-site dosimetry reviews where measurements on therapy machines are made, records are reviewed and personnel are interviewed. The program's remote audit tools include mailed dosimeters (OSLD/TLD) to verify output calibration, comparison of dosimetry data with RPC 'standard' data, evaluation of benchmark and patient calculations to verify the treatment planning algorithms, review of institution's QA procedures and records, and use of anthropomorphic phantoms to verify tumor dose delivery. The RPC endeavors to assist institutions in finding the origins of any detected discrepancies, and to resolve them.

RESULTS

Ninety percent of institutions receiving dosimetry recommendations has remained level for the past 5 years. The most frequent recommendations were for not performing TG-40 QA tests, wedge factors, small field size output factors and off-axis factors. Since TG-51 was published, the number of beam calibrations audited during visits with ion chambers, that met the RPC's ±3% criterion, decreased initially but has risen to pre-TG-51 levels. The OSLD/TLD program shows that only ∼3% of the beams are outside our ±5% criteria, but these discrepancies are distributed over 12-20% of the institutions. The percent of institutions with ï,³ l beam outside the RPC's criteria is approximately the same whether OSLD/TLD or ion chambers were used. The first time passing rate for the anthropomorphic phantoms is increasing with time. The prostate phantom has the highest pass rate while the spine phantom has the lowest.

CONCLUSIONS

Numerous dosimetry errors continue to be discovered by the RPC's QA program and the RPC continues to play an important role in helping institutions resolve these errors. This work was supported by PHS grants CA10953 and CA081647 awarded by NCI.

SU-E-T-102: Evaluation of the Characteristics of TLD LiF:Mg.Ti-100 Powder: A Measure of Consistency between Multiple Batches of Powder

PURPOSE

Analyze the characteristics of TLD LiF-100 powder between multiple LiF crystal batches.

METHODS

The RPC used TLD LiF-100 encapsulated powder to verify the output for photon and electron beams for 4 to 23 MV X-ray beams and 6 to 23 MeV electron beams, respectively, from the past 15 years. During that time period, the RPC commissioned more than 15 batches of TLD powder. Commissioning of each batch of powder encompassed determining the system sensitivity (dose response), linearity, energy and fading characteristics of each batch of powder to determine the correction factors for the calculation of dose. The system sensitivity is the signal/mg per unit known dose of 60Co for each reading session. Other correction factors account for the loss of signal (fading) between the irradiation and read dates, supralinearity of the dose response and energy differences as compared to the 60Co irradiated standards.

RESULTS

More than 15 batches of TLD were commissioned to determine correction factors for the calculation of dose. The correction for fading, a characteristic of the LiF crystal, varied by ±1% between the multiple batches. The linearity correction, between 25 and 600cGy, normalized to 300cGy, showed a maximum variation of ±3% between batches. The energy correction factors, as defined for the RPC beam output audit system varied within ±1.7% (one std dev.) for the 15 batches. The system sensitivity is highly dependent on the LiF crystal grown for each batch, specific TLD reader and reading session conditions. The system sensitivity, while keeping the readers and reading sessions constant, varied by as much as 20% between batches.

CONCLUSIONS

Each batch of LiF-100 TLD powder showed variability in their powder characteristics such that calculation of dose accurately, with minimal uncertainty, requires a new commissioning. Work supported by PHS CA010953 awarded by NCI, DHHS.

Role of the 4-phosphopantetheinyl transferase of Trichoderma virens in secondary metabolism and induction of plant defense responses

Trichoderma virens is a ubiquitous soil fungus successfully used in biological control due to its efficient colonization of plant roots. In fungi, 4-phosphopantetheinyl transferases (PPTases) activate enzymes involved in primary and secondary metabolism. Therefore, we cloned the PPTase gene ppt1 from T. virens and generated PPTase-deficient (?ppt1) and overexpressing strains to investigate the role of this enzyme in biocontrol and induction of plant defense responses. The ?ppt1 mutants were auxotrophic for lysine, produced nonpigmented conidia, and were unable to synthesize nonribosomal peptides. Although spore germination was severely compromised under both low and high iron availability, mycelial growth occurred faster than the wild type, and the mutants were able to efficiently colonize plant roots. The ?ppt1 mutants were unable of inhibiting growth of phytopathogenic fungi in vitro. Arabidopsis thaliana seedlings co-cultivated with wild-type T. virens showed increased expression of pPr1a:uidA and pLox2:uidA markers, which correlated with enhanced accumulation of salicylic acid (SA), jasmonic acid, camalexin, and resistance to Botrytis cinerea. Co-cultivation of A. thaliana seedlings with ?ppt1 mutants compromised the SA and camalexin responses, resulting in decreased protection against the pathogen. Our data reveal an important role of T. virens PPT1 in antibiosis and induction of SA and camalexin-dependent plant defense responses.

In vitro exposure of human fibroblasts to local anaesthetics impairs cell growth

Lidocaine, bupivacaine or ropivacaine are used routinely to manage perioperative pain. Sparse data exist evaluating the effects of local anaesthetics (LA) on fibroblasts, which are involved actively in wound healing. Therefore, we investigated the effects of the three LA to assess the survival, viability and proliferation rate of fibroblasts. Human fibroblasts were exposed to 0·3 mg/ml and 0·6 mg/ml of each LA for 2 days, followed by incubation with normal medium for another 1, 4 or 7 days (group 1). Alternatively, cells were incubated permanently with LA for 3, 6 or 9 days (group 2). Live cell count was assessed using trypan blue staining. Viability was measured by the tetrazolium bromide assay. Proliferation tests were performed with the help of the colorimetric bromodeoxyuridine assay. Production of reactive oxygen species (ROS) was determined, measuring the oxidation of non-fluorescent-2,7'-dichlorofluorescin. Treatment of cells with the three LA showed a concentration-dependent decrease of live cells, mitochondrial activity and proliferation rate. Group arrangement played a significant role for cell count and proliferation, while exposure time influenced viability. Among the analysed LA, bupivacaine showed the most severe cytotoxic effects. Increased production of ROS correlated with decreased viability of fibroblasts in lidocaine- and bupivacaine-exposed cells, but not upon stimulation with ropivacaine. This study shows a concentration-dependent cytotoxic effect of lidocaine, bupivacaine and ropivacaine on fibroblasts in vitro, with more pronounced effects after continuous incubation. A possible mechanism of cell impairment could be triggered by production of ROS upon stimulation with lidocaine and bupivacaine.