External validation of a machine learning based algorithm to differentiate hepatic mucinous cystic neoplasms from benign hepatic cysts

PURPOSE

To externally validate an algorithm for non-invasive differentiation of hepatic mucinous cystic neoplasms (MCN) from benign hepatic cysts (BHC), which differ in management.

METHODS

Patients with cystic liver lesions pathologically confirmed as MCN or BHC between January 2005 and March 2022 from multiple institutions were retrospectively included. Five readers (2 radiologists, 3 non-radiologist physicians) independently reviewed contrast-enhanced CT or MRI examinations before tissue sampling and applied the 3-feature classification algorithm described by Hardie et al. to differentiate between MCN and BHC, which had a reported accuracy of 93.5%. The classification was then compared to the pathology results. Interreader agreement between readers across different levels of experience was evaluated with Fleiss' Kappa.

RESULTS

The final cohort included 159 patients, median age of 62 years (IQR [52.0, 70.0]), 66.7% female (106). Of all patients, 89.3% (142) had BHC, and the remaining 10.7% (17) had MCN on pathology. Agreement for class designation between the radiologists was almost perfect (Fleiss' Kappa 0.840, p < 0.001). The algorithm had an accuracy of 98.1% (95% CI [94.6%, 99.6%]), a positive predictive value of 100.0% (95% CI [76.8%, 100.0%]), a negative predictive value of 97.9% (95% CI [94.1%, 99.6%]), and an area under the receiver operator characteristic curve (AUC) of 0.911 (95% CI [0.818, 1.000]).

CONCLUSION

The evaluated algorithm showed similarly high diagnostic accuracy in our external, multi-institutional validation cohort. This 3-feature algorithm is easily and rapidly applied and its features are reproducible among radiologists, showing promise as a clinical decision support tool.

STUDY OF THE PERFORMANCE OF THE POLYVINYLPYRROLIDONE POLYMER PHENOL CAPTURE

The Lowry Method (LM) is daily used in proteic amount determination in different biological samples, however, phenolic components presence is a limiting factor in the method. This paper investigates the LM output about protein amount, in a phenolic matrix, applying a Phenol Capture Method (PCM), from pre-treatment of the sample with polyvinylpyrrolidone (PVP). For this, a factorial experimental design was applied, with a central point and three independent variables. The best conditions suggested by the planning were 75% (w/w) of PVP, 5000 rpm, and 10°C, with a protein content of 87.80 µg.mL-1 and an experimental error of 22.9%. The PCM is efficient for protein amount quantification by LM, preventing the turbidity of the medium. Assessments using the PCM are still necessary to verify the matrix effect and the response as a function of protein variation (method validation), however, the results obtained allowed a reasonable estimate of the protein content under the conditions usual.

Multicenter External Validation of a Nomogram for Predicting Positive Prostate-specific Membrane Antigen/Positron Emission Tomography Scan in Patients with Prostate Cancer Recurrence

BACKGROUND

A nomogram has recently been developed to predict ⁶⁸Ga-labeled prostate-specific membrane antigen (PSMA)-11 positron emission tomography (PET)/computed tomography (PSMA-PET) results in recurrent prostate cancer (PCa) patients.

OBJECTIVE

To perform external validation of the original nomogram in a multicentric setting.

DESIGN, SETTING, AND PARTICIPANTS

A total of 1639 patients who underwent PSMA-PET for prostate-specific antigen (PSA) relapse after radical therapy were retrospectively included from six high-volume PET centers. The external cohort was stratified according to clinical setting categories: group 1: first-time biochemical recurrence (n = 774); group 2: PSA relapse after salvage therapy (n = 499); group-3: biochemical persistence after radical prostatectomy (n = 210); and group-4: advanced-stage PCa before second-line systemic therapies (n = 124).

INTERVENTION

PSMA-PET in recurrent PCa.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

PSMA-PET detection rate was assessed in the overall population and in each subgroup. A multivariable logistic regression model was produced to evaluate the predictors of a positive scan. The performance characteristics of the model were assessed by quantifying the predictive accuracy (PA) according to model calibration. The Youden's index was used to find the best nomogram's cutoff. Decision curve analysis (DCA) was implemented to quantify the nomogram's clinical net benefit.

RESULTS AND LIMITATIONS

In the external cohort, the overall detection rate was 53.8% versus 51.2% in the original population. At multivariate analysis, International Society of Urological Pathology grade group, PSA, PSA doubling time, and clinical setting were independent predictors of a positive scan (all p ≤ 0.02). The PA of the nomogram was identical to the original model (82.0%); the model showed an optimal calibration curve. The best nomogram's cutoff was 55%. In the DCA, the nomogram revealed clinical net benefit when the threshold nomogram probabilities were ≥20%. The retrospective design is a major limitation.

CONCLUSIONS

The original nomogram exhibited excellent characteristics on external validation. The incidence of a false negative scan can be reduced if PSMA-PET is performed when the predicted probability is ≥20%.

PATIENT SUMMARY

A nomogram has been developed to predict prostate-specific membrane antigen/positron emission tomography (PSMA-PET) results for recurrent prostate cancer (PCa). The nomogram represents an easy tool in the decision-making process of recurrent PCa.

Fundamental frequency related parameters in Brazilians with COVID-19

This study compares fundamental frequency (f_o) and fundamental frequency standard deviation (f_oSD) of COVID-19 patients with the same parameters in the speech of subjects without COVID-19, and verifies whether there is an effect of age and sex in the patient group. Both groups, subjects with and without COVID-19, are formed by Brazilian Portuguese speakers. Speech samples were obtained from 100 patients with mild to severe symptoms of COVID-19, and 100 healthy subjects. A single 31-syllable Portuguese sentence was used as the elicitation material for all subjects. The recordings were divided into four age groups. The acoustic measures were semi-automatically extracted and analyzed by a series of analyses of variance. Patients with COVID-19 present vocal differences in f_o-related parameters when compared to healthy subjects, that is, patient voices presented higher f_o and f_oSD with respect to control voices. In addition, for patient voices, there was an age and sex effect on f_o SD values. Vocal parameters of women and elderly subjects showed more marked differences in f_o-related parameters, indicating that patient voices are higher-pitched and have a higher variation of f_o SD. Consequently, f_o-related parameters may be tested as vocal biomarkers in the screening of respiratory insufficiency by voice analysis, in patients with severe symptoms of COVID-19.

Prostate Cancer Imaging: What We Already Know and What Is on the Horizon

Conventional as well as advanced imaging modalities contribute to accurate detection of prostate cancer and have important roles in screening, staging, active surveillance, and evaluation for biochemical recurrence.

Luteolin Improves Perivascular Adipose Tissue Profile and Vascular Dysfunction in Goto-Kakizaki Rats

We investigated the effects of luteolin on metabolism, vascular reactivity, and perivascular adipose tissue (PVAT) in nonobese type 2 diabetes mellitus animal model, Goto-Kakizaki (GK) rats. Methods: Wistar and GK rats were divided in two groups: (1) control groups treated with vehicle; (2) groups treated with luteolin (10 mg/kg/day, for 2 months). Several metabolic parameters such as adiposity index, lipid profile, fasting glucose levels, glucose and insulin tolerance tests were determined. Endothelial function and contraction studies were performed in aortas with (PVAT+) or without (PVAT−) periaortic adipose tissue. We also studied vascular oxidative stress, glycation and assessed CRP, CCL2, and nitrotyrosine levels in PVAT. Results: Endothelial function was impaired in diabetic GK rats (47% (GK − PVAT) and 65% (GK + PVAT) inhibition of maximal endothelial dependent relaxation) and significantly improved by luteolin treatment (29% (GK − PVAT) and 22% (GK + PVAT) inhibition of maximal endothelial dependent relaxation, p < 0.01). Vascular oxidative stress and advanced glycation end-products’ levels were increased in aortic rings (~2-fold, p < 0.05) of diabetic rats and significantly improved by luteolin treatment (to levels not significantly different from controls). Periaortic adipose tissue anti-contractile action was significantly rescued with luteolin administration (p < 0.001). In addition, luteolin treatment significantly recovered proinflammatory and pro-oxidant PVAT phenotype, and improved systemic and metabolic parameters in GK rats. Conclusions: Luteolin ameliorates endothelial dysfunction in type 2 diabetes and exhibits therapeutic potential for the treatment of vascular complications associated with type 2 diabetes.

An international expert opinion statement on the utility of PET/MR for imaging of skeletal metastases

BACKGROUND

MR is an important imaging modality for evaluating musculoskeletal malignancies owing to its high soft tissue contrast and its ability to acquire multiparametric information. PET provides quantitative molecular and physiologic information and is a critical tool in the diagnosis and staging of several malignancies. PET/MR, which can take advantage of its constituent modalities, is uniquely suited for evaluating skeletal metastases. We reviewed the current evidence of PET/MR in assessing for skeletal metastases and provided recommendations for its use.

METHODS

We searched for the peer reviewed literature related to the usage of PET/MR in the settings of osseous metastases. In addition, expert opinions, practices, and protocols of major research institutions performing research on PET/MR of skeletal metastases were considered.

RESULTS

Peer-reviewed published literature was included. Nuclear medicine and radiology experts, including those from 13 major PET/MR centers, shared the gained expertise on PET/MR use for evaluating skeletal metastases and contributed to a consensus expert opinion statement. [18F]-FDG and non [18F]-FDG PET/MR may provide key advantages over PET/CT in the evaluation for osseous metastases in several primary malignancies.

CONCLUSION

PET/MR should be considered for staging of malignancies where there is a high likelihood of osseous metastatic disease based on the characteristics of the primary malignancy, hight clinical suspicious and in case, where the presence of osseous metastases will have an impact on patient management. Appropriate choice of tumor-specific radiopharmaceuticals, as well as stringent adherence to PET and MR protocols, should be employed.

Omentin: A novel therapeutic approach for the treatment of endothelial dysfunction in type 2 diabetes

BACKGROUND

Perivascular adipose tissue (PVAT) locally influences the functioning of blood vessels and promotes vascular complications associated with diabetes and obesity. The aim of this work was to study the impact of omentin-1 on endothelial function and PVAT in a non-obese type 2 diabetes mellitus animal model, Goto-Kakizaki (GK) rats with or without high fat diet.

MATERIAL AND METHODS

Diabetic GK rats were divided into four groups: 1) control group; 2) group treated with omentin-1; 3) group of GK rats fed a high fat diet (GKHFD) and 4) group of GKHFD treated with omentin-1. Several in vivo parameters such as adiposity and Lee indexes, lipid profile, fasting glucose levels, glucose and insulin tolerance tests were determined. At the vascular level, endothelial dependent and independent relaxation and contraction studies were performed in aortic rings in the absence (PVAT-) or in the presence (PVAT+) of thoracic PVAT. We also evaluated vascular oxidative stress and determined the pro-inflammatory status of PVAT.

RESULTS

Endothelium-dependent relaxation to acetylcholine, assessed by wire myography, was impaired in GK and GKHFD rats and improved by the omentin-1 treatment. In addition, vascular superoxide production was increased in the vascular wall of diabetic rats, accompanied by reduced nitric oxide bioavailability and significantly improved by omentin treatment. PVAT anti-contractile action found under physiological conditions was lost in type 2 diabetes, and partially recovered with omentin-1 administration. In addition, omentin-1 treatment significantly improved proinflammatory and pro-oxidant PVAT phenotype (decreasing C-reactive protein and nitrotyrosine levels). Furthermore, it was observed an improvement in various systemic and metabolic biochemical parameters of diabetic animals treated for one month with omentin.

CONCLUSIONS

Omentin-1 ameliorates endothelial dysfunction in type 2 diabetes and presents therapeutic potential for the treatment of vascular complications associated with type 2 diabetes.

Recovery of bioactive compounds from white grape (Vitis vinifera L.) stems as potential antimicrobial agents for human health

The grape is a matrix rich in bioactive compounds and its production generates large quantities of by-products, such as grape stems, which, to date, present low commercial value. However, there is a growing interest in the application of this material as a source of phenolic compounds. Therefore, the present study aims at assessing the phytochemical profile of (poly)phenolic extracts of white Portuguese grape stem varieties produced in the Região Demarcada do Douro (Portugal). The antioxidant activity determined by several assays, as well as the antimicrobial activity using the disc diffusion method against human gastrointestinal pathogenic bacteria of the hydromethanolic extracts, were evaluated. This work presents very positive results as the rich composition in phenolic compounds (94.71–123.09 mg GA⁻¹ and 0.02–73.79 mg g⁻¹ for the total phenol content and for individual phenolics, respectively) presented by grape stems can explain the high antioxidant (0.37–1.17 mmol Trolox g⁻¹) and antimicrobial activities against, essentially, Gram-positive bacteria, and in some cases with higher efficacy than commercial antibiotics. Thus, demonstrating that this wine by-product should deserve greater attention from the pharmaceutical industries due to its excellent biological properties and characteristics not yet applied.

Nutrients, Antinutrients, Phenolic Composition, and Antioxidant Activity of Common Bean Cultivars and their Potential for Food Applications

Phaseolus vulgaris L. is the most commonly consumed legume in the world, given its high vegetable protein content, phenolic compounds, and antioxidant properties. It also represents one of the most sustainable, low-carbon and sources of food available at present to man. This study aims to identify the nutrients, antinutrients, phenolic composition, and antioxidant profile of 10 common bean cultivars (Arikara yellow, butter, cranberry, red kidney, navy, pinto, black, brown eyed, pink eyed, and tarrestre) from two harvest years, thereby assessing the potential of each cultivar for specific applications in the food industry. Navy and pink eyed beans showed higher potential for enrichment of foodstuffs and gluten-free products due to their higher protein and amino acid contents. Additionally, red kidney, cranberry and Arikara yellow beans had the highest content of phenolic compounds and antioxidant properties, which can act as functional ingredients in food products, thus bringing health benefits. Our study highlights the potential of using specific bean cultivars in the development of nutrient-enriched food and as functional ingredients in diets designed for disease prevention and treatment.

Impact of 68GA-PSMA PET / CT on treatment of patients with recurrent / metastatic high risk prostate cancer - a multicenter study

Purpose:

The purpose of our study was to evaluate the clinical impact of ⁶⁸Ga-PSMA PET / CT in the setting of biochemical recurrence of prostate cancer.

Materials and Methods:

We retrospectively evaluated 125 prostate cancer patients submitted to the ⁶⁸Ga-PSMA PET / CT due to biochemical recurrence. The parameters age, Gleason score, PSA levels, and the highest SUVmax were correlated to potential treatment changes. The highest SUVmax values were correlated with age and Gleason score. The median follow-up time was 24 months.

Results:

⁶⁸Ga-PSMA PET / CT led to a treatment change in 66 / 104 (63.4%) patients (twenty-one patients were lost to follow-up). There was a significant change of treatment plan in patients with a higher Gleason score (P = 0.0233), higher SUVmax (p = 0.0306) and higher PSA levels (P < 0.0001; median PSA = 2.55 ng / mL).

Conclusion:

⁶⁸Ga-PSMA PET / CT in prostate cancer patients with biochemical recurrence has a high impact in patient management.

New grape stems' isolated phenolic compounds modulate reactive oxygen species, glutathione, and lipid peroxidation in vitro: Combined formulations with vitamins C and E

The antioxidant potential of grape (Vitis vinífera L.) stems has been reported in the last decade although no identification of the individual compounds responsible for such action has been done. In this work, polyphenolic extract of grape stems was processed resorting to semi-preparative HPLC, allowing to obtain 5 purified polyphenols (caftaric acid, malvidin-3-O-glucoside, quercetin-3-O-glucuronide, mailvidin-3-O-(6-O-caffeoyl)-glucoside, and Σ-viniferin), which were fully characterized by HPLC-PDA-ESI-MSⁿ. Isolated compounds were featured on their radical scavenging capacity (DPPH and ABTS), cell viability, anti-inflammatory activity, and capacity to modulate the level of reactive oxygen species, glutathione, lipid peroxidation, and overall oxidative stress in a biological model (human keratinocytes) in vitro, under basal and oxidative conditions. The results obtained noticed the combinations malvidin-3-O-glucoside+Vitamin E and quercetin-3-O-glucuronide+vitamin C as the most effective, allowing to improve the capacity of complete extracts or individual compounds, and being candidates to be used in the development of new functional products.

Diagnostic performance of FDG-PET/MRI and WB-DW-MRI in the evaluation of lymphoma: a prospective comparison to standard FDG-PET/CT

BACKGROUND

Use of FDG-PET/CT for staging and restaging of lymphoma patients is widely incorporated into current practice guidelines. Our aim was to prospectively evaluate the diagnostic performance of FDG-PET/MRI and WB-DW-MRI compared with FDG-FDG-PET/CT using a tri-modality PET/CT-MRI system.

METHODS

From 04/12 to 01/14, a total of 82 FDG-PET/CT examinations including an additional scientific MRI on a tri-modality setup were performed in 61 patients. FDG-PET/CT, FDG-PET/MRI, and WB-DW-MRI were independently analyzed. A lesion with a mean ADC below a threshold of 1.2 × 10(-3) mm(2)/s was defined as positive for restricted diffusion. FDG-PET/CT and FDG-PET/MRI were evaluated for the detection of lesions corresponding to lymphoma manifestations according to the German Hodgkin Study Group. Imaging findings were validated by biopsy (n = 21), by follow-up imaging comprising CT, FDG-PET/CT, and/or FDG-PET/MRI (n = 32), or clinically (n = 25) (mean follow-up: 9.1 months).

RESULTS

FDG-PET/MRI and FDG-PET/CT accurately detected 188 lesions in 27 patients. Another 54 examinations in 35 patients were negative. WB-DW-MRI detected 524 lesions, of which 125 (66.5% of the aforementioned 188 lesions) were true positive. Among the 188 lesions positive for lymphoma, FDG-PET/MRI detected all 170 instances of nodal disease and also all 18 extranodal lymphoma manifestations; by comparison, WB-DW-MRI characterized 115 (67.6%) and 10 (55.6%) lesions as positive for nodal and extranodal disease, respectively. FDG-PET/MRI was superior to WB-DW-MRI in detecting lymphoma manifestations in patients included for staging (113 vs. 73), for restaging (75 vs. 52), for evaluation of high- (127 vs. 81) and low-grade lymphomas (61 vs. 46), and for definition of Ann Arbor stage (WB-DW-MRI resulted in upstaging in 60 cases, including 45 patients free of disease, and downstaging in 4).

CONCLUSION

Our results indicate that FDG-PET/CT and FDG-PET/MRI probably have a similar performance in the clinical work-up of lymphomas. The performance of WB-DW-MRI was generally inferior to that of both FDG-PET-based methods but the technique might be used in specific scenarios, e.g., in low-grade lymphomas and during surveillance.

Musicians' working memory for tones, words, and pseudowords

Studies investigating factors that influence tone recognition generally use recognition tests, whereas the majority of the studies on verbal material use self-generated responses in the form of serial recall tests. In the present study we intended to investigate whether tonal and verbal materials share the same cognitive mechanisms, by presenting an experimental instrument that evaluates short-term and working memories for tones, using self-generated sung responses that may be compared to verbal tests. This paradigm was designed according to the same structure of the forward and backward digit span tests, but using digits, pseudowords, and tones as stimuli. The profile of amateur singers and professional singers in these tests was compared in forward and backward digit, pseudoword, tone, and contour spans. In addition, an absolute pitch experimental group was included, in order to observe the possible use of verbal labels in tone memorization tasks. In general, we observed that musical schooling has a slight positive influence on the recall of tones, as opposed to verbal material, which is not influenced by musical schooling. Furthermore, the ability to reproduce melodic contours (up and down patterns) is generally higher than the ability to reproduce exact tone sequences. However, backward spans were lower than forward spans for all stimuli (digits, pseudowords, tones, contour). Curiously, backward spans were disproportionately lower for tones than for verbal material-that is, the requirement to recall sequences in backward rather than forward order seems to differentially affect tonal stimuli. This difference does not vary according to musical expertise.

THORACOLUMBAR BURST FRACTURES: CORRELATION BETWEEN KYPHOSIS AND FUNCTION POST NON-OPERATIVE TREATMENT

OBJECTIVE

To assess the correlation between kyphosis and post-traumatic symptoms in patients undergoing conservative treatment for thoracolumbar burst fractures.

METHODS

A retrospective study was carried out with 36 patients meeting the inclusion criteria for this kind of fracture classified as Denis and Magerl's subtype A3 and treated with anti-gravitational casting or TLSO. The mean age of patients was 50.83 years, ranging from 13 to 83 years, being 20 male and 16 female subjects. The treatment outcome was evaluated based on the SF-36 questionnaire, on Denis scores for pain and work and Frankel clinical and neurological scale. The quantification of pain was based on the visual analogue scale for pain. The measurement of the residual kyphosis was obtained by the Cobb method at admission and at the end of the follow-up.

RESULTS

A weak positive correlation (r = 0.563; p > 0.001) was found between residual kyphosis and pain score (EVA). No correlation was found between final kyphosis and SF-36 and Denis scores (p > 0.05).

CONCLUSION

There is no evident correlation between residual kyphosis, functional outcome and patients' symptoms.

Medicinal plants popularly used in the Brazilian Tropical Atlantic Forest

A survey of medicinal plants used by rural and urban inhabitants of the three cities of the Tropical Atlantic Forest, Region of Vale do Ribeira, State of São Paulo, Brazil was performed by means of 200 interviews with medicinal plant users and extractors and, traditional healers. One hundred fourteen herbal remedies were recorded and the following information reported: Latin, vernacular and English names, plant part used, forms of preparation and application of the herbal remedies, medicinal or food uses, areas of plant collection, economic importance (when available) and other data.

Effect of insulin on immunological phagocytosis by macrophages

It was shown that, in physiological concentrations, insulin enhances, in vitro, the immunological phagocytosis of sensitized sheep erythrocytes by cultured mouse peritoneal macrophages. Insulin seems to stimulate macrophage phagocytosis as a cholinomimetic agonist by increasing the intracellular levels of cyclic GMP.