A water-soluble polyphosphorhydrazone Janus dendrimer built by "click" chemistry as support for Ru-complexes in catalysis.

The field of supported catalysis has experienced increased attention with respect to the development of novel architectures for immobilizing catalytic species, aiming to maintain or enhance their activity while facilitating the easy recovery and reuse of the active moiety. Dendrimers have been identified as promising candidates capable of imparting such properties to catalysts through selective functionalization. The present study details the synthesis of two polyphosphorhydrazone (PPH) dendrons, each incorporating azide or acetylene groups at the core for subsequent coupling through "click" triazole chemistry. Employing this methodology, a novel PPH Janus dendrimer was successfully synthesized, featuring ten polyethylene glycol (PEG) chains on one side of the structure and ten Ru(p-cymene) derivatives on the other. This design was intended to confer dual properties, influencing solubility modulation, and allowing the presence of active catalytic moieties. The synthesized dendrimer underwent testing in the isomerization of allyl alcohols in organic solvents and biphasic solvent mixtures. The results demonstrated a positive dendritic effect compared with model monometallic and bimetallic species, providing a proof-of-concept for the first PPH Janus dendrimer with tested applications in catalysis.

Strategies for the Preparation of Phosphorus Janus Dendrimers and Their Properties.

Dendrimers, being highly branched monodispersed macromolecules, predominantly exhibit identical terminal functionalities within their structural framework. Nonetheless, there are instances where the presence of two distinct surface functionalities becomes advantageous for the fulfilment of specific properties. To achieve this objective, one approach involves implementing Janus dendrimers, consisting of two dendrimeric wedges terminated by dissimilar functionalities. The prevalent method for creating these structures involves the synthesis of dendrons that possess a core functionality that complements that of a second dendron, facilitating their coupling to generate the desired dendrimers. In this comprehensive review, various techniques employed in the fabrication of phosphorus-based Janus dendrimers are elucidated, displaying the different coupling methodologies employed between the two units. The advantages of phosphorus dendrimers over classic dendrimers will be shown, as the presence of at least one phosphorus atom in each generation allows for the easy monitoring of reactions and the confirmation of purity through a simple technique such as 31P NMR, as these structures typically exhibit easily interpretable patterns.

Harmful cyanobacterial aerosolization dynamics in the airshed of a eutrophic estuary.

In addition to obvious negative effects on water quality in eutrophic aquatic ecosystems, recent work suggests that cyanobacterial harmful algal blooms (CHABs) also impact air quality via emissions carrying cyanobacterial cells and cyanotoxins. However, the environmental controls on CHAB-derived aerosol and its potential public health impacts remain largely unknown. Accordingly, the aims of this study were to 1) investigate the occurrence of microcystins (MC) and putatively toxic cyanobacterial communities in particulate matter ≤ 2.5 µm in diameter (PM2.5), 2) elucidate environmental conditions promoting their aerosolization, and 3) identify associations between CHABs and PM2.5 concentrations in the airshed of the Chowan River-Albemarle Sound, an oligohaline, eutrophic estuary in eastern North Carolina, USA. In summer 2020, during peak CHAB season, continuous PM2.5 samples and interval water samples were collected at two distinctive sites for targeted analyses of cyanobacterial community composition and MC concentration. Supporting air and water quality measurements were made in parallel to contextualize findings and permit statistical analyses of environmental factors driving changes in CHAB-derived aerosol. MC concentrations were low throughout the study, but a CHAB dominated by Dolichospermum occurred from late June to early August. Several aquatic CHAB genera recovered from Chowan River surface water were identified in PM2.5 during multiple time points, including Anabaena, Aphanizomenon, Dolichospermum, Microcystis, and Pseudanabaena. Cyanobacterial enrichment in PM2.5 was indistinctive between subspecies, but at one site during the early bloom, we observed the simultaneous enrichment of several cyanobacterial genera in PM2.5. In association with the CHAB, the median PM2.5 mass concentration increased to 8.97 µg m-3 (IQR = 5.15), significantly above the non-bloom background of 5.35 µg m-3 (IQR = 3.70) (W = 1835, p < 0.001). Results underscore the need for highly resolved temporal measurements to conclusively investigate the role that CHABs play in regional air quality and respiratory health risk.

Modelo de atención integral en el segundo nivel: Experiencia de la Unidad de Especialidades Médicas / Care models at the second level: Experience of the Medical Specialties Unit

Resumen Objetivo: Reportar la implementación y los beneficios del Modelo de atención integral en el segundo nivel: Experiencia de la Unidad de Especialidades Médicas, su utilidad en el manejo y seguimiento de los pacientes con enfermedades crónicas. Material y métodos: Se lograron implementar 9 consultorios de atención médica de la siguiente forma, 2 de Endocrinología, 3 consultorios de Clínica de Enfermedades Crónicas, uno de educación en diabetes e hipertensión, así como 3 de apoyo nutricional. Se midió valores absolutos del número de consultas durante los años 2017, 2018, 2019 y parte del 2020. Así mismo se buscó identificar las patologías más prevalentes con la idea en tener un mejor control y seguimiento de los pacientes, con una mejor organización de personal de atención médico y de enfermería. Resultados y discusión: Se lograron incrementar los números de consulta, con un control y seguimiento más estricto de los pacientes, además de los beneficios en cuanto a la formación y capacitación de médicos residentes, generales tanto militares como profesionales de la salud civiles para enfrentar estos padecimientos prevalentes en nuestro país.

Abstract Objective: To report the implementation as well as the benefits of the Comprehensive Care Model at the second level: Experience of the Medical Specialties Unit, and assess its usefulness in the management and monitoring of patients with chronic diseases. Material and methods: 9 medical care clinics were implemented as follows, 2 for Endocrinology, 3 Clinics for Chronic Diseases, one for education in diabetes and hypertension, as well as 3 for nutritional support. Absolute values of the number of consultations were measured during the years 2017, 2018, 2019 and part of 2020. Likewise, it was sought to identify the most prevalent pathologies with the idea of having a better control and monitoring of patients, with a better organization of medical and nursing care personnel. Results and discussion: It was possible to increase the consultation numbers, with a stricter control and monitoring of patients, in addition to the benefits in terms of training and training of resident doctors, both military generals and civilian health professionals to face these prevalent conditions in our country.

Synthesis and Catalytic Properties of a Very Latent Selenium-Chelated Ruthenium Benzylidene Olefin Metathesis Catalyst.

Herein, we describe a study of the synthesis, characterization, and catalytic properties of a cis-dichlorido seleno-chelated Hoveyda-Grubbs type complex (Ru8). Such a complex has been obtained through a straightforward and high-yielding synthetic protocol in three steps from the commercially available 2-bromobenzaldehyde in good overall yield (54%). The catalytic profile, especially the latency of this complex, has been probed through selected olefin metathesis reactions such as ring-closing metathesis (RCM), self-cross-metathesis (self-CM) and ring-opening metathesis polymerization (ROMP). In addition to its high latency, the selenium Hoveyda-type complex Ru8 exhibits a switchable behavior upon thermal activation. Of interest, while the corresponding sulfur-chelated Hoveyda type catalyst is reported to be only activated by heat, the selenium analogue was found to be active upon both heat and light irradiation.

Treatment of osteochondritis dissecans of the patella in adolescents with nanofractured autologous matrix-induced chondrogenesis (NAMIC): A report of five cases.

PURPOSE: Osteochondritis dissecans (OCD) of the patella is a very rare affliction. The aim of this case series is to evaluate the effectiveness of the Nanofractured Autologous Matrix-Induced Chondrogenesis (NAMIC) technique for the treatment of OCD in young adults. METHODS: Five consecutive patients with patellar osteochondral lesions treated with NAMIC were prospectively studied. There were 4 males and 1 female with a mean age of 15.2 years, ranging from 12 to 18 years. Clinically, they presented pain when going up and down stairs or squatting, effusion, swelling and functional limitation. The International Cartilage Repair Society (ICRS) grade was III in 4 patients and IV in 1 patient. Patients were functionally evaluated with the Lysholm knee score, the Tegner Activity Score (TAS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) and radiologically using the Magnetic resonance Observation of Cartilage Repair Tissue (MOCART) score. RESULTS: All the scores significantly improved two years after surgery with respect to pre-operative values (Lysholm score from 63.8 ± 3.9 before surgery to 91 ± 3.2 at 2 years; Tegner activity score from 3.6 ± 0.5 to 8.2 ± 0.8 and the KOOS score from 45.2 ± 2.6 to 91.2 ± 2.4). Both the X-rays and the Magnetic Resonance Imaging (MRI) showed good joint regularity with an average MOCART of 80 ± 7.1/100. CONCLUSIONS: Treatment of juvenile patellar osteochondritis dissecans with the NAMIC technique seems to be a reliable technique in the short term to restore the patella joint surface and obtain good functional results.

PCSK-9 Inhibitors in a Real-World Setting and a Comparison Between Alirocumab and Evolocumab in Heterozygous FH Patients.

A real-world setting study of familial hypercholesterolemia (FH) patients who received Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors in a specialized referral center in Mexico City. Ten patients between the ages of 18 and 70 years, with a diagnosis of FH according to Dutch Lipid Clinic Network (DLCN) criteria, with failure to achieve their Low-density lipoprotein Cholesterol (LDL-C) goals, and with standard therapy between 2016 and 2017 enrolled in a simple randomization in which a group of 5 participants received alirocumab (75 mg every 2 weeks) and the remaining 5 patients received evolocumab (140 mg every 2 weeks). Comparative analysis was made, analyzing the means of LDL at baseline at 4, 6, and 12 weeks. The evolocumab group had an average initial LDL-C of 277 mg/dL, which, after 12 weeks of treatment, was significantly reduced to 116 mg/dL; P = 0.04 (95% confidence interval [CI]: 11.5-310.9). The alirocumab group with a mean initial LDL-C of 229 mg/dL showed a reduction of LDL-C levels at 12 weeks of treatment to 80 mg/dL; P = 0.008 (95% CI: 63.8-233.7). In conclusion, PCSK9 inhibitors are an excellent treatment option in patients with FH who do not reach their LDL-C goals with standard therapy or due to intolerance to the standard therapy. There is no difference in the lipid-lowering effect between both PSCK9 inhibitors.

Picophytoplankton dynamics in a large temperate estuary and impacts of extreme storm events.

Picophytoplankton (PicoP) are increasingly recognized as significant contributors to primary productivity and phytoplankton biomass in coastal and estuarine systems. Remarkably though, PicoP composition is unknown or not well-resolved in several large estuaries including the semi-lagoonal Neuse River Estuary (NRE), a tributary of the second largest estuary-system in the lower USA, the Pamlico-Albemarle Sound. The NRE is impacted by extreme weather events, including recent increases in precipitation and flooding associated with tropical cyclones. Here we examined the impacts of moderate to extreme (Hurricane Florence, September 2018) precipitation events on NRE PicoP abundances and composition using flow cytometry, over a 1.5 year period. Phycocyanin-rich Synechococcus-like cells were the most dominant PicoP, reaching ~ 106 cells mL-1, which highlights their importance as key primary producers in this relatively long residence-time estuary. Ephemeral "blooms" of picoeukaryotic phytoplankton (PEUK) during spring and after spikes in river flow were also detected, making PEUK periodically major contributors to PicoP biomass (up to ~ 80%). About half of the variation in PicoP abundance was explained by measured environmental variables. Temperature explained the most variation (24.5%). Change in total dissolved nitrogen concentration, an indication of increased river discharge, explained the second-most variation in PicoP abundance (15.9%). The short-term impacts of extreme river discharge from Hurricane Florence were particularly evident as PicoP biomass was reduced by ~ 100-fold for more than 2 weeks. We conclude that precipitation is a highly influential factor on estuarine PicoP biomass and composition, and show how 'wetter' future climate conditions will have ecosystem impacts down to the smallest of phytoplankton.

All-Arthroscopic Nanofractured Autologous Matrix-Induced Chondrogenesis (A-NAMIC) Technique for the Treatment of Focal Chondral Lesions of the Knee.

Nanofractured autologous matrix-induced chondrogenesis (NAMIC©) is a 1-step technique that combines nanofracture needling to induce bone marrow stimulation (BMS) and the use of cell-free collagen matrix to optimize cartilage regeneration. In this Technical Note, we describe a modification of the NAMIC procedure using mosaicplasty trephines to prepare the lesion surface and to shape collagen implants in an all-arthroscopic approach (A-NAMIC). This technique is indicated for the treatment of International Cartilage Repair Society grade III to IV knee chondral lesions of ≤4 cm2. After damaged cartilage is debrided, trephines are used to create a flat, circular lesion surfaces. Subsequently, BMS is performed with nanofracture, eliciting reproducible and stop-controlled subchondral bone perforations of 9-mm depth and 1-mm width. The collagen membrane is then cut to size with the trephine, placed over the prepared defect, and secured with fibrin glue, preventing loss of regenerating cells and growth factors to the joint space. Using trephines allows the rapid and precise creation of smooth defect surfaces with known dimensions, ensuring optimal lesion coverage. Additionally, nanofracture reduces trabecular compaction and allows for a deeper access to subchondral bone in comparison with conventional microfracture, improving lesion filling and production of cartilage with higher hyaline content.

Locoregional staging using magnetic resonance imaging in rectal cancer: influence of diffusion-weighted imaging in the diagnostic accuracy.

OBJECTIVE: To assess whether the accuracy in locoregional staging using magnetic resonance imaging (MRI) in rectal cancer (primary or post-chemoradiotherapy) improves by adding diffusion-weighted imaging, according to the radiologist's degree of experience. METHOD: Retrospective study on 100 MRI records (1.5 T, 2011-2016) from patients with rectal cancer (reference standard: histology of surgical specimens). Ten radiologists (three experienced in rectal cancer, three specialized in other areas and four residents) individually reviewed each case twice: first, evaluating just high-resolution T2-weighted sequences; second, evaluation of diffusion-weighted plus high-resolution ones. The analysis focused on the differentiation between early (0-I) and advanced (II-IV) stages. Accuracy, sensitivity/specificity and predictive values were calculated. RESULTS: Experienced radiologists showed some worsening by adding diffusion-weighted imaging, mainly at primary staging (accuracy: 0.769 to 0.701). Inexperienced radiologists presented a post-chemoradiotherapy improvement (accuracy: 0.574 to 0.642; specificity of 19.1 to 29.8%), although with no other remarkable changes. Residents demonstrated a worsening at primary staging by adding diffusion (accuracy: 0.670 to 0.633; specificity: 45.8 to 39.6%), but post-chemoradiotherapy improvement (sensitivity: 80.6 to 87%). The differences between both reviews were not statistically significant. CONCLUSIONS: No significant differences were found in the distinction between early and advanced rectal tumors secondary to adding diffusion-weighted imaging to high-resolution T2-weighted sequences.

OBJETIVO: Evaluar si la eficacia en la estadificación locorregional por resonancia magnética (RM) del cáncer de recto (primaria o posneoadyuvancia) mejora al añadir imágenes potenciadas en difusión, según la experiencia previa del radiólogo. MÉTODO: Estudio retrospectivo sobre 100 RM de 1.5 T (2011-2016) de pacientes con cáncer rectal (estándar de referencia: estadiaje histológico de pieza quirúrgica). Diez radiólogos (tres con experiencia en cáncer rectal, tres inexpertos y cuatro residentes) evaluaron individualmente cada caso dos veces: primero, solo secuencias T2 de alta resolución; segundo, valoración conjunta con difusión. Se analizó la diferenciación entre estadios precoces (0-I) y avanzados (II-IV), y se calcularon la precisión, la sensibilidad y la especificidad, y los valores predictivos. RESULTADOS: Al agregar la difusión, los radiólogos experimentados presentaron peores resultados, sobre todo en estadiaje primario (precisión: 0.769 a 0.701). Los inexpertos mostraron mejoría posneoadyuvancia (precisión: 0.574 a 0.642; especificidad: 19.1 a 29.8%), sin otros cambios destacables. Los residentes manifestaron peores resultados en estadiaje primario (precisión: 0.670 a 0.633; especificidad: 45.8-39.6%), pero mejoría posneoadyuvancia (sensibilidad: 80.6 a 87%). Las diferencias entre ambas revisiones no fueron estadísticamente significativas. CONCLUSIONES: No se encontraron diferencias significativas en la distinción entre tumores rectales precoces y avanzados al añadir secuencias de difusión al uso de secuencias T2 de alta resolución.

Tocilizumab in glucocorticoid-resistant graves orbitopathy. A case series report of a mexican population.

PURPOSE: To describe pre- to post-treatment changes in clinical activity score (CAS) and exophthalmometry in patients with Graves orbitopathy treated with tocilizumab (TCZ). MATERIAL AND METHODS: Eight Mexican patients presenting with active Graves orbitopathy (CAS>3/7) previously treated with glucocorticoids received 1 monthly dose of TCZ for 6 months. CAS, EUGOGO severity assessment and exophthalmometry were used to evaluate clinical status, with serum measurement of thyroid-stimulating hormone receptor antibodies (TR-Ab) for biochemical evaluation before and after application of TCZ. RESULTS: Eight patients were analyzed: 6 male (75%), 2 female (25%): mean age, 45.9±11.2 years; mean weight, 85±18.3 kg. Mean TR-Ab level at treatment outset was 291.9±96.4%, mean CAS 4.1±0.3 and mean exophthalmometry 21.2±3.2 mm. After TCZ treatment, mean TR-Ab level fell to 172.7±54% (P=0.001), mean CAS to 1.1±0.6 (P=0.001) and mean exophthalmometry to 19.3±2 mm (P=0.02). CONCLUSIONS: TCZ is a therapeutic option for glucocorticoid-resistant orbitopathy, and should be considered in second line due to the cost of treatment or in first line in patients with contraindications to intravenous GC pulse therapy.

Use of PCSK9 Inhibitor in a Mexican Boy with Compound Heterozygous Familial Hypercholesterolemia: A Case Report.

We report on the case of an 8-year-old Mexican male, with a 3-year-old clinical diagnosis of familial hypercholesterolemia, and the difficulties encountered in his treatment while in our care. His treatment started with a regimen consisting of ezetimibe/simvastatin, cholestyramine, and a dietary plan of 1600 calories, with a limited intake of 200 mg of cholesterol per day. Problems arose when the patient's low-density lipoprotein cholesterol (LDL) levels did not meet ideal targets, which prompted the use of LDL cholesterol apheresis (not available in Mexico) for 6 months. As a last resort, PCSK9 inhibitors were administered but the LDL levels remained in the 600 mg/dL range. AmbryGenetics conducted a genetic test employing the Sanger method. The results suggested that there were 2 different mutations for each allele of the same LDL receptor gene (c.249delTinsGG and p.(Cys109Arg)), located in exons 3 and 4, respectively. We identified compound heterozygous mutations in our index case, with him having both the p.C109R mutation (from the maternal lineage), as well as a c.249delTinsGG mutation (from the paternal lineage). The p.C109R mutation has been previously reported, not only in Mexico, but in European regions (Germany, Czech Republic, Ireland, Italy) as well. Functional studies indicated a residual enzymatic activity of 15% to 30% for heterozygotes. To date, the variant c.249delTinsGG has not been reported. This case study illustrates the fact that in Mexico there are limited options available for treatment in such a scenario. As medical professionals, we are limited by the tools at our disposal.

Primary and post-chemoradiotherapy MRI detection of extramural venous invasion in rectal cancer: the role of diffusion-weighted imaging.

OBJECTIVE: To assess the added value of diffusion-weighted imaging (DWI) to high-resolution T2-weighted sequences (HRT2w) in MRI detection of extramural venous infiltration (EMVI), according to the previous experience of radiologists. METHODS: A cross-sectional study of a retrospective database including 1.5 T MRI records from 100 patients with biopsy-proven rectal cancer (2011-2016; 75 male/25 female, average 63 y/o), which included primary staging (54) and post-chemoradiotherapy follow-up MRIs (46). The reference standard was histology of surgical specimens. All cases were individually blindly reviewed by ten radiologists: three specialists in abdominal radiology, three specialized in different areas and four residents. In each case, the presence of EMVI was assessed twice: first, using just HRT2w; second, with DWI added to HRT2w. The results were pooled by experience, analyzing sensitivity, specificity, accuracy (area under ROC curve), likelihood ratios, predictive values and overstaging/understaging. RESULTS: Addition of DWI improved diagnostic performance by specialists radiologists, particularly post-chemoradiotherapy (accuracy 0.74-0.84; positive likelihood ratio 3.9-9.1; overstaging 16-8%), less so at primary staging (specificity 76-87.2%; overstaging 21-11%). Non-specialist radiologists also improved, but only at primary staging (accuracy 0.59-0.63). Residents showed small changes, except for notably increased sensitivity in both primary staging (35.7-43%) and post-chemoradiotherapy (41.7-58.3%) staging, at the expense of increased overstaging. CONCLUSIONS: The addition of DWI improved the diagnostic performance of EMVI by experienced radiologists, downgrading overstaging, especially in post-chemoradiotherapy follow-up. It resulted in fewer changes for inexperienced radiologists (enhanced primary staging) and residents (increased sensitivity).

A Spin Coating Method To Deposit Iridium-Based Catalysts onto Silicon for Water Oxidation Photoanodes.

Silicon has shown promise for use as a small band gap (1.1 eV) absorber material in photoelectrochemical (PEC) water splitting. However, the limited stability of silicon in acidic electrolyte requires the use of protection strategies coupled with catalysts. Herein, spin coating is used as a versatile method to directly coat silicon photoanodes with an IrOx oxygen evolution reaction (OER) catalyst, reducing the processing complexity compared to conventional fabrication schemes. Biphasic strontium chloride/iridium oxide (SrCl2:IrOx) catalysts are also developed, and both catalysts form photoactive junctions with silicon and demonstrate high photoanode activity. The iridium oxide photoanode displays a photocurrent onset at 1.06 V vs reversible hydrogen electrode (RHE), while the SrCl2:IrOx photoanode onsets earlier at 0.96 V vs RHE. The differing potentials are consistent with the observed photovoltages of 0.43 and 0.53 V for the IrOx and SrCl2:IrOx, respectively. By measuring the oxidation of a reversible redox couple, Fe(CN)63-/4-, we compare the charge carrier extraction of the devices and show that the addition of SrCl2 to the IrOx catalyst improves the silicon-electrolyte interface compared to pure IrOx. However, the durability of the strontium-containing photoanode remains a challenge, with its photocurrent density decreasing by 90% over 4 h. The IrOx photoanode, on the other hand, maintained a stable photocurrent density over this timescale. Characterization of the as-prepared and post-tested material structure via Auger electron spectroscopy identifies catalyst film cracking and delamination as the primary failure modes. We propose that improvements to catalyst adhesion should further the viability of spin coating as a technique for photoanode preparation.

Morphology control of metal-modified zirconium phosphate support structures for the oxygen evolution reaction.

The electrochemical oxygen evolution reaction (OER) is the half-cell reaction for many clean-energy production technologies, including water electrolyzers and metal-air batteries. However, its sluggish kinetics hinders the performance of those technologies, impeding them from broader implementation. Recently, we reported the use of zirconium phosphate (ZrP) as a support for transition metal catalysts for the oxygen evolution reaction (OER). These catalysts achieve promising overpotentials with high mass activities. Herein, we synthesize ZrP structures with controlled morphology: hexagonal platelets, rods, cubes, and spheres, and subsequently modify them with Co(ii) and Ni(ii) cations to assess their electrochemcial OER behavior. Through inductively coupled plasma mass-spectrometry measurements, the maximum ion exchange capacity is found to vary based on the morphology of the ZrP structure and cation selection. Trends in geometric current density and mass activity as a function of cation selection are discussed. We find that the loading and coverage of cobalt and nickel species on the ZrP supports are key factors that control OER performance.

An immersed boundary neural network for solving elliptic equations with singular forces on arbitrary domains.

In this paper, we present a deep learning framework for solving two-dimensional elliptic equations with singular forces on arbitrary domains. This work follows the ideas of the physical-inform neural networks to approximate the solutions and the immersed boundary method to deal with the singularity on an interface. Numerical simulations of elliptic equations with regular solutions are initially analyzed in order to deeply investigate the performance of such methods on rectangular and irregular domains. We study the deep neural network solutions for different number of training and collocation points as well as different neural network architectures. The accuracy is also compared with standard schemes based on finite differences. In the case of singular forces, the analytical solution is continuous but the normal derivative on the interface has a discontinuity. This discontinuity is incorporated into the equations as a source term with a delta function which is approximated using a Peskin's approach. The performance of the proposed method is analyzed for different interface shapes and domains. Results demonstrate that the immersed boundary neural network can approximate accurately the analytical solution for elliptic problems with and without singularity.

Primary and post-chemoradiotherapy staging using MRI in rectal cancer: the role of diffusion imaging in the assessment of perirectal infiltration.

PURPOSE: To analyze changes in MRI diagnostic accuracy in main rectal tumor (T) evaluation resulting from the use of diffusion-weighted imaging (DWI), according to the degree of experience of the radiologist. METHODS: This is a cross-sectional study of a database including one hundred 1.5 T MRI records (2011-2016) from patients with biopsy-proven rectal cancer, including primary staging and post-chemoradiotherapy follow-up. All cases were individually blindedly reviewed by ten radiologists: three experienced in rectal cancer, three specialized in other areas, and four residents. Each case was assessed twice to detect perirectal infiltration: first, evaluating just high-resolution T2-weighted sequences (HRT2w); second, evaluation of DWI plus HRT2w sequences. Results were pooled by experience, calculating accuracy (area under ROC curve), sensitivity and specificity, predictive values, likelihood ratios, and overstaging/understaging. Histology of surgical specimens provided the reference standard. RESULTS: DWI significantly improved specificity by experienced radiologists in primary staging (63.2% to 75.9%) and, to a lesser extent, positive likelihood ratio (2.06 to 2.87); minimal changes were observed post-chemoradiotherapy, with a slight decrease of accuracy (0.657 to 0.626). Inexperienced radiologists showed a similar pattern, but with slight enhancement post-chemoradiotherapy (accuracy 0.604 to 0.621). Residents experienced small changes, with increased sensitivity/decreased specificity in both primary (69% to 72%/67.2% to 64.7%) and post-chemoradiotherapy (68.1% to 73.6%/47.3% to 44.6%) staging. CONCLUSIONS: Adding DWI to HRT2w significantly improved specificity for the detection of perirectal infiltration at primary staging by experienced radiologists and also by inexperienced ones, although to a lesser extent. In the post-neoadjuvant treatment subgroup, only minimal changes were observed.

Successful Multimodal Treatment of an IGF2-Producing Solitary Fibrous Tumor With Acromegaloid Changes and Hypoglycemia.

Doege-Potter syndrome with acromegaloid facial changes is extremely rare. Uncooked cornstarch along with glucocorticoids have been used as supportive care in patients with non-islet cell tumor hypoglycemia (NICTH). Preoperative embolization of hepatic solitary fibrous tumors (SFT) with NICTH has yielded unsatisfactory results. Herein we present the case of a 61-year-old man with a 3-month history of severe frequent hypoglycemic episodes and acromegaloid facial changes. During a spontaneous hypoglycemia (26 mg/dL), laboratory values showed a hypoinsulinemic pattern with low levels of GH, IGFPB3, and an IGF2/IGF1 ratio of 8.5:1. Cross-sectional imaging revealed a large (16 × 13 × 11 cm) hepatic tumor, and cytology was consistent with SFT. A preoperative right portal embolization was performed in an effort to induce normal remnant liver hypertrophy to allow for safe tumor resection. After the procedure, uncooked starch treatment followed by prednisone was started, achieving complete remission of hypoglycemic episodes in the preoperative setting. He subsequently underwent partial hepatectomy. The histologic diagnosis was compatible with a potentially malignant SFT. The patient had an excellent outcome with complete remission of hypoglycemia, improvement of facial acromegaloid changes, and no further evidence of disease. To our knowledge, this is the first case of a patient with Doege-Potter syndrome with acromegaloid facial changes induced by a potentially malignant liver SFT, treated successfully with a multimodal approach consisting of uncooked cornstarch, low-dose prednisone, preoperative embolization, and complete surgical resection. The use of cornstarch and low-dose glucocorticoids may be an adequate treatment in advance of undergoing surgery.

Rescue Snorkel Technique in a Giant Ruptured Aortic Aneurysm With Thoracic Endovascular Aortic Repair Failure.

A 67-year-old man was sent to our center because of progressively worsening chest pain. A giant ruptured thoracic aortic aneurysm was documented. We performed a successfully rescue snorkel technique for thoracic endovascular aortic repair failure because of type IA endoleak after the first endoprosthesis implantation. The patient was discharged after 6 weeks. (Level of Difficulty: Advanced.).