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Fast radio bursts (FRBs) are brief, bright, extragalactic radio flashes1,2. Their physical origin remains unknown, but dozens of possible models have been postulated3. Some FRB sources exhibit repeat bursts4-7. Although over a hundred FRB sources have been discovered8, only four have been localized and associated with a host galaxy9-12, and just one of these four is known to emit repeating FRBs9. The properties of the host galaxies, and the local environments of FRBs, could provide important clues about their physical origins. The first known repeating FRB, however, was localized to a low-metallicity, irregular dwarf galaxy, and the apparently non-repeating sources were localized to higher-metallicity, massive elliptical or star-forming galaxies, suggesting that perhaps the repeating and apparently non-repeating sources could have distinct physical origins. Here we report the precise localization of a second repeating FRB source6, FRB 180916.J0158+65, to a star-forming region in a nearby (redshift 0.0337 ± 0.0002) massive spiral galaxy, whose properties and proximity distinguish it from all known hosts. The lack of both a comparably luminous persistent radio counterpart and a high Faraday rotation measure6 further distinguish the local environment of FRB 180916.J0158+65 from that of the single previously localized repeating FRB source, FRB 121102. This suggests that repeating FRBs may have a wide range of luminosities, and originate from diverse host galaxies and local environments.
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Cavity-free lasing in atmospheric air has stimulated intense research toward a fundamental understanding of underlying physical mechanisms. In this Letter, we identify a new mechanism-a third-harmonic photon mediated resonant energy transfer pathway leading to population inversion in argon via an initial three-photon excitation of nitrogen molecules irradiated by intense 261 nm pulses-that enables bidirectional two-color cascaded lasing in atmospheric air. By making pump-probe measurements, we conclusively show that such cascaded lasing results from superfluorescence rather than amplified spontaneous emission. Such cascaded lasing with the capability of producing bidirectional multicolor coherent pulses opens additional possibilities for remote sensing applications.
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OBJECTIVE: To determine the diagnostic accuracy of prenatal ultrasound in detecting coarctation of the aorta (CoA). METHODS: An individual participant data meta-analysis was performed to report on the strength of association and diagnostic accuracy of different ultrasound signs in detecting CoA prenatally. MEDLINE, EMBASE and CINAHL were searched for studies published between January 2000 and November 2021. Inclusion criteria were fetuses with suspected isolated CoA, defined as ventricular and/or great vessel disproportion with right dominance on ultrasound assessment. Individual participant-level data were obtained by two leading teams. PRISMA-IPD and PRISMA-DTA guidelines were used for extracting data, and the QUADAS-2 tool was used for assessing quality and applicability. The reference standard was CoA, defined as narrowing of the aortic arch, diagnosed after birth. The most commonly evaluated parameters on ultrasound, both in B-mode and on Doppler, constituted the index test. Summary estimates of sensitivity, specificity, diagnostic odds ratio (DOR) and likelihood ratios were computed using the hierarchical summary receiver-operating-characteristics model. RESULTS: The initial search yielded 72 studies, of which 25 met the inclusion criteria. Seventeen studies (640 fetuses) were included. On random-effects logistic regression analysis, tricuspid valve/mitral valve diameter ratio > 1.4 and > 1.6, aortic isthmus/arterial duct diameter ratio < 0.7, hypoplastic aortic arch (all P < 0.001), aortic isthmus diameter Z-score of < -2 in the sagittal (P = 0.003) and three-vessel-and-trachea (P < 0.001) views, pulmonary artery/ascending aorta diameter ratio > 1.4 (P = 0.048) and bidirectional flow at the foramen ovale (P = 0.012) were independently associated with CoA. Redundant foramen ovale was inversely associated with CoA (P = 0.037). Regarding diagnostic accuracy, tricuspid valve/mitral valve diameter ratio > 1.4 had a sensitivity of 72.6% (95% CI, 48.2-88.3%), specificity of 65.4% (95% CI, 46.9-80.2%) and DOR of 5.02 (95% CI, 1.82-13.9). The sensitivity and specificity values were, respectively, 75.0% (95% CI, 61.1-86.0%) and 39.7% (95% CI, 27.0-53.4%) for pulmonary artery/ascending aorta diameter ratio > 1.4, 47.8% (95% CI, 14.6-83.0%) and 87.6% (95% CI, 27.3-99.3%) for aortic isthmus diameter Z-score of < -2 in the sagittal view and 74.1% (95% CI, 58.0-85.6%) and 62.0% (95% CI, 41.6-78.9%) for aortic isthmus diameter Z-score of < -2 in the three-vessel-and-trachea view. Hypoplastic aortic arch had a sensitivity of 70.0% (95% CI, 42.0-88.6%), specificity of 91.3% (95% CI, 78.6-96.8%) and DOR of 24.9 (95% CI, 6.18-100). The diagnostic yield of prenatal ultrasound in detecting CoA did not change significantly when considering multiple categorical parameters. Five of the 11 evaluated continuous parameters were independently associated with CoA (all P < 0.001) but all had low-to-moderate diagnostic yield. CONCLUSIONS: Several prenatal ultrasound parameters are associated with an increased risk for postnatal CoA. However, diagnostic accuracy is only moderate, even when combinations of parameters are considered. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
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Coartação Aórtica , Sensibilidade e Especificidade , Ultrassonografia Pré-Natal , Humanos , Coartação Aórtica/diagnóstico por imagem , Coartação Aórtica/embriologia , Ultrassonografia Pré-Natal/métodos , Gravidez , FemininoRESUMO
Peanut is mostly grown in calcareous soils with high pH which are deficient in available iron (Fe2+) for plant uptake causing iron deficiency chlorosis (IDC). The most pertinent solution is to identify efficient genotypes showing tolerance to limited Fe availability in the soil. A field screening of 40 advanced breeding lines of peanut using NRCG 7472 and ICGV 86031 as IDC susceptible and tolerant checks, respectively, was envisaged for four years. PBS 22040 and 29,192 exhibited maximum tolerance while PBS 12215 and 12,185 were most susceptible. PBS 22040 accumulated maximum seed resveratrol (5.8 ± 0.08 ppm), ferulic acid (378.6 ± 0.31 ppm) and Fe (45.59 ± 0.41 ppm) content. Enhanced chlorophyll retention (8.72-9.50 µg ml-1), carotenoid accumulation (1.96-2.08 µg ml-1), and antioxidant enzyme activity (APX: 35.9-103.9%; POX: 51- 145%) reduced the MDA accumulation (5.61-9.11 µM cm-1) in tolerant lines. The overexpression of Fe transporters IRT1, ZIP5, YSL3 was recorded to the tune of 2.3-9.54; 1.45-3.7; 2.20-2.32- folds respectively in PBS 22040 and 29,192, over NRCG 7472. PBS 22040 recorded the maximum pod yield (282 ± 4.6 g/row), hundred kernel weight (55 ± 0.7 g) and number of pods per three plants (54 ± 1.7). The study thus reports new insights into the roles of resveratrol, ferulic acid and differential antioxidant enzyme activities in imparting IDC tolerance. PBS 22040, being the best performing line, can be the potent source of IDC tolerance for introgression in high yielding but susceptible genotypes under similar edaphic conditions. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01321-9.
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Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.
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Institutional variations in parathyroid adenoma localisation are largely dictated by local experience and availability of imaging investigations, with no consensus on the optimal approach. This review evaluates the role of multiple imaging techniques in primary hyperparathyroidism and highlights their advantages and limitations in different clinical contexts. A clinico-radiological review of parathyroid imaging techniques is illustrated with example cases and data from the literature. These include high-resolution ultrasound, 99mTc-sestamibi planar scintigraphy with and without thyroid subtraction techniques, integrated 99mTc-sestamibi single-photon-emission computed tomography (SPECT)/computed tomography (CT), four-dimensional (4D) CT, and other techniques, such as magnetic resonance imaging, integrated 18F-choline/11C-methionine positron-emission tomography (PET)/CT and angiographic selective venous sampling. The crucial role of parathyroid embryological and gross anatomy in informing the surgical approach to parathyroidectomy is discussed. Finally, a systematic approach to imaging is proposed to maximise the accuracy of imaging localisation of parathyroid lesions, which is crucial for optimal patient management.
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Hiperparatireoidismo Primário , Neoplasias das Paratireoides , Humanos , Hiperparatireoidismo Primário/diagnóstico por imagem , Hiperparatireoidismo Primário/cirurgia , Imagem Multimodal , Glândulas Paratireoides/diagnóstico por imagem , Neoplasias das Paratireoides/diagnóstico por imagem , Neoplasias das Paratireoides/cirurgia , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Sestamibi , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
The present study was aimed to elucidate the host-virus interactions using RNA-Seq analysis at 1 h and 8 h of post-infection of sheeppox virus (SPPV) in lamb testis cell. The differentially expressed genes (DEGs) and the underlying mechanisms linked to the host immune responses were obtained. The protein-protein interaction (PPI) network analysis and ingenuity pathway analysis (IPA) illustrated the interaction between the DEGs and their involvement in cell signalling responses. Highly connected hubs viz. AURKA, CHEK1, CCNB2, CDC6 and MAPK14 were identified through PPI network analysis. IPA analysis showed that IL-6- and ERK5-mediated signalling pathways were highly enriched at both time points. The TP53 gene was identified to be the leading upstream regulator that directly responded to SPPV infection, resulting in downregulation at both time points. The study provides an overview of how the lamb testis genes and their underlying mechanisms link to growth and immune response during SPPV infection.
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Capripoxvirus , Infecções por Poxviridae , Doenças dos Ovinos , Masculino , Ovinos , Animais , Testículo , Infecções por Poxviridae/veterinária , Capripoxvirus/genética , Transcriptoma , Perfilação da Expressão GênicaRESUMO
Anthrax, by Bacillus anthracis, remains a dreadful fatal hazard worldwide. The currently used anthrax vaccines are plagued by numerous issues that limit their widespread use. As an immunization approach targeting both extracellular antigens and toxins of B. anthracis may achieve better sterile immunity, the present investigation designed a bicistronic secretory anti-anthrax DNA vaccine targeting immune response against toxin and cells. The efficacy of the vaccine was compared with monocistronic DNA vaccines and the currently used anthrax vaccine. For this, mice were immunized with the developed vaccine containing pag (encoding protective antigen to block toxin) and eag genes (encoding EA1 to target cells) of B. anthracis through DNA-prime/Protein-boost (D/P) and DNA prime/DNA-boost (D/D) approaches. There was a >2 and > 5 fold increase in specific antibody level by D/D and D/P approaches respectively, on 42nd days post-immunization (dpi). Serum cytokine profiling showed that both Th1 and Th2 immune responses were elicited, with more Th2 responses in D/P strategy. More importantly, challenge with 100 times LD50 of B. anthracis at 42nd dpi exhibited maximum cumulative survival (83.33 %) by bicistronic D/P approach. Remarkably, immunization with EA1 delayed mortality onset in infection. The study forms the first report on complement-dependent bactericidal activity of antiEA1 antibodies. In short, co-immunization of PA and EA1 through the developed bicistronic DNA vaccine would be an effective immunization approach in anthrax vaccination. Further, D/P strategy could enhance vaccine-induced immunity against B. anthracis. Altogether, the study generates certain critical insights having direct applications in next-generation vaccine development against anthrax.
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Vacinas contra Antraz , Bacillus anthracis , Vacinas de DNA , Animais , Vacinas contra Antraz/genética , Anticorpos Antibacterianos , Antígenos de Bactérias/genética , Bacillus anthracis/genética , DNA , Imunidade , Camundongos , Camundongos Endogâmicos BALB C , Vacinação , Vacinas de DNA/genéticaRESUMO
PURPOSE: To systematically review the literature evaluating clinical utility of imaging metrics derived from baseline fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for prediction of progression-free (PFS) and overall survival (OS) in patients with classical Hodgkin lymphoma (HL) and diffuse large B cell lymphoma (DLBCL). METHODS: A search of MEDLINE/PubMed, Web of Science, Cochrane, Scopus and clinicaltrials.gov databases was undertaken for articles evaluating PET/CT imaging metrics as outcome predictors in HL and DLBCL. PRISMA guidelines were followed. Risk of bias was assessed using the Quality in Prognosis Studies (QUIPS) tool. RESULTS: Forty-one articles were included (31 DLBCL, 10 HL). Significant predictive ability was reported in 5/20 DLBCL studies assessing SUVmax (PFS: HR 0.13-7.35, OS: HR 0.83-11.23), 17/19 assessing metabolic tumour volume (MTV) (PFS: HR 2.09-11.20, OS: HR 2.40-10.32) and 10/13 assessing total lesion glycolysis (TLG) (PFS: HR 1.078-11.21, OS: HR 2.40-4.82). Significant predictive ability was reported in 1/4 HL studies assessing SUVmax (HR not reported), 6/8 assessing MTV (PFS: HR 1.2-10.71, OS: HR 1.00-13.20) and 2/3 assessing TLG (HR not reported). There are 7/41 studies assessing the use of radiomics (4 DLBCL, 2 HL); 5/41 studies had internal validation and 2/41 included external validation. All studies had overall moderate or high risk of bias. CONCLUSION: Most studies are retrospective, underpowered, heterogenous in their methodology and lack external validation of described models. Further work in protocol harmonisation, automated segmentation techniques and optimum performance cut-off is required to develop robust methodologies amenable for clinical utility.
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Linfoma Difuso de Grandes Células B , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Fluordesoxiglucose F18 , Humanos , Linfoma Difuso de Grandes Células B/diagnóstico por imagem , Linfoma Difuso de Grandes Células B/terapia , Tomografia por Emissão de Pósitrons , Prognóstico , Estudos Retrospectivos , Resultado do Tratamento , Carga TumoralRESUMO
BACKGROUND: We evaluated the effect of cardiac resynchronization therapy (CRT) on septal perfusion and thickening at 6 months post implantation assessed on Tc99m-MIBI Gated myocardial perfusion SPECT (GMPS).We also studied the association of change in septal perfusion and thickening with primary outcome defined as at least one [improvement in ≥1NYHA class, left ventricular ejection fraction (LVEF) by ≥ 5%, reduction of end-systolic volume (ESV) by ≥ 15%, and improvement ≥ 5 points in Minnesota living with heart failure questionnaire (MLHFQ)]. METHOD: One hundred and five patients underwent clinical and GMPS evaluation before and at 6 months post CRT. RESULT: Post CRT there was significant improvement in mean normalized septal perfusion uptake and in septal thickening (P value = 0.001, both). There was no significant relation between improvement in septal perfusion and primary outcome. However, improvement in septal thickening was statistically significant with favorable primary outcome (P = 0.001).There was no significant correlation between improvement of septal perfusion and improvement in LVEF, reduction in End diastolic volume (EDV), ESV, and Left ventricular Dyssynchrony (LVD). But, there was significant correlation between improvement of septal thickening and these parameters. CONCLUSION: Improvement in septal thickening was associated with reverse remodeling, improvement in LVEF, and reduction of LVD.
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Terapia de Ressincronização Cardíaca , Septos Cardíacos/patologia , Função Ventricular Esquerda/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão do Miocárdio , Estudos Prospectivos , Tecnécio Tc 99m Sestamibi , Tomografia Computadorizada de Emissão de Fóton Único , Adulto JovemRESUMO
AIM: To analyse the additional clinical value of protocol-driven and selective use of multidetector single-photon-emission tomography/computed tomography (SPECT/CT) in oncology patients undergoing whole-body bone scintigraphy (BS) and to analyse reporter confidence in diagnosis with and without SPECT/CT. MATERIALS AND METHODS: During a 2-year period, 2,954 whole-body BS examinations were performed in oncology patients, with 444 (15%) undergoing additional protocol-driven SPECT/CT. Retrospective evaluation of planar BS and SPECT/CT images was performed by two experienced dual-trained nuclear medicine radiologists. The BS and SPECT/CT images were graded blindly using a five-point scale designed to evaluate the likelihood of a lesion being benign or malignant. Interpretation was applied on a per-patient basis. RESULTS: There was a 74.5% increase in definitive diagnostic classification and a 26.6% reduction in equivocal findings with SPECT/CT when compared to BS alone (p<0001). Of cases initially classified as "probably benign" on BS, 5.1% (10/193) were reclassified to "probably malignant" (1%) or "malignant" (4.1%) using the SPECT/CT data. The highest impact in reporter confidence was seen with SPECT/CT in the interpretation of lesions within the pelvis (34%), ribs (23%), lumbar spine (22%), and thoracic spine (21%). CONCLUSION: Protocol-driven, selective use of SPECT/CT imaging to augment planar BS reduces equivocal findings and improves reporter confidence whilst minimising the impact on patient and reporting workflows.
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Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/secundário , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Idoso , Algoritmos , Protocolos Clínicos , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Compostos Radiofarmacêuticos , Medronato de Tecnécio Tc 99m , Imagem Corporal Total , Fluxo de TrabalhoRESUMO
BACKGROUND: Management of children with disorders of cerebrospinal fluid (CSF) circulation is a common aspect of paediatric neurosurgical practice. Sport and physical activity play an integral role in the lives of patients in this age group. However, there is little evidence to support the dissemination of appropriate advice to children regarding such activities. The aim of this study was to evaluate the perspectives of clinicians across the UK regarding the participation of children with disorders of CSF circulation in sports. METHODS: Questionnaires were distributed to Consultant Paediatric Neurosurgeons practising across the UK via the Society of British Neurological Surgeons (SBNS). Five different patient scenarios were supplied, and participants were asked to choose whether they would advise participation in the following sports: Taekwondo, rugby, skiing, and football. RESULTS: An overall response rate of 66.7% (36 out of 54 paediatric neurosurgeons) was achieved. The following percentages of clinicians advocated football, rugby, Taekwondo, and skiing across all scenarios: 96%, 75%, 77%, and 97%, respectively. The majority of responders (91.2%) relied on personal experience when providing advice, whilst 50% used available literature and 19.4% used available guidelines. CONCLUSIONS: There is a paucity of evidence in the literature to support the dissemination of appropriate advice to children with disorders of CSF circulation regarding participation in sports. Our findings demonstrate that the majority of clinicians rely on personal experience to make such decisions, emphasizing the necessity of larger scale studies to inform evidence-based guidelines.
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Derivações do Líquido Cefalorraquidiano , Neurocirurgiões , Criança , Humanos , Inquéritos e QuestionáriosRESUMO
BACKGROUND: The Echelon circular™ powered stapler (ECP stapler) obviates the need for manual firing of conventional circular staplers during the construction of a colorectal anastomosis, but has not been evaluated clinically. The aim of this study was to perform a clinical evaluation of this stapler. METHODS: A retrospective review of the initial clinical experience of a single surgeon using the ECP stapler for left-sided colorectal anastomosis construction during elective colorectal resections for benign and malignant disease was conducted by analyzing results from a prospectively maintained study database. Additionally, four attending colorectal and/or general surgeons who had performed ≥ 5 colorectal operations with the ECP stapler were invited to complete an anonymous online survey to subjectively assess the user experience with the device. Statistical analysis was conducted using Microsoft Excel Version 15.33. RESULTS: Seventeen patients underwent left-sided anastomotic reconstruction using the ECP stapler. All donuts (proximal and distal) were intact. Anastomotic integrity was evaluated using the air-leak test utilizing flexible video sigmoidoscopy. No leaks were observed, although one patient (5.9%) developed a postoperative pelvic abscess. The anonymous survey was completed by all four surgeons. Subjective evaluation of the ECP stapler suggests that the overall stapling quality, overall device ease-of-use, and the overall perception of anastomotic quality as above average when compared to manual 'end-to-end anastomosis' (EEA) stapling devices. CONCLUSIONS: In an initial clinical evaluation of the ECP stapler, the safety and ease-of-use of the device appears to be satisfactory. Powered stapling and the design of '3D stapling' may provide advantages over manual systems, and may improve the construction quality of left-sided colorectal anastomosis.
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Neoplasias Colorretais , Grampeamento Cirúrgico , Anastomose Cirúrgica , Neoplasias Colorretais/cirurgia , Humanos , Reto/cirurgia , Estudos Retrospectivos , Grampeadores CirúrgicosRESUMO
Sheeppox disease is associated with significant losses in sheep production world over. The sheep pox virus, the goatpox virus, and the lumpy skin disease virus cannot be distinguished by conventional serological tests. Identification of these pathogens needs molecular methods. In this study, seven genes viz. EEV maturation protein-F12L, Virion protein-D3R, RNA polymerase subunit-A5R, Virion core protein-A10L, EEV glycoprotein-A33R, VARV B22R homologue, and Kelch like protein-A55R that cover the start, middle, and end of the genome were selected. These genes were amplified from Roumanian-Fanar vaccine strain and Jaipur virulent strain, cloned, and sequenced. On analysis with the available database sequences, VARV B22R homologue was identified as a marker for phylogenetic reconstruction for classifying the sheeppox viruses of the ungulates. Further, divergence time dating with VARV B22R gene accurately predicted the sheeppox disease outbreak involving Jaipur virulent strain.
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Capripoxvirus/classificação , Capripoxvirus/genética , Evolução Molecular , Mutação , Filogenia , Infecções por Poxviridae/virologia , Proteínas Virais/genética , Animais , Sequência de Bases , Clonagem Molecular , Fases de Leitura Aberta , Análise de Sequência de DNA , Ovinos , Doenças dos Ovinos/virologiaRESUMO
IMPORTANCE: There is variation in the literature for sclerotomy and intravitreal injection placement in young children, ranging from 0.5 to 3.0 mm from the limbus. We assess the accuracy of scleral transillumination to identify the ciliary body in infants for safe sclerotomy and intravitreal injections in young children. BACKGROUND: The study compares the perilimbal "dark band" seen on scleral transillumination (STI) with the ultrasound biomicroscopy (UBM), and compares these measurements with the current guidelines for sclerotomy in infants. DESIGN: Prospective case series in a tertiary paediatric hospital. PARTICIPANTS: Children aged ≤36 months undergoing general anaesthesia for eye procedures. METHODS: Scleral transillumination was performed to measure the perilimbal dark band. UBM of the ciliary body region was then performed, and correlated with transillumination findings. MAIN OUTCOME MEASURES: The midpoints of STI and UBM were compared to current cadaver-based guidelines to assess the safe point for sclerotomy. RESULTS: Twenty children were recruited, 36 STI and 35 UBM measurements were obtained. The posterior edge of the dark band had good correlation with the posterior border of the ciliary body. Transillumination and UBM correlated well for midpoint measurements. The midpoint of the dark band on transillumination was confirmed to be in the ciliary body by UBM in all cases. CONCLUSIONS AND RELEVANCE: The STI technique is a useful and fast technique to demonstrate the ciliary body. The midpoint of the dark band on STI correlates well with the UBM, and has a potential use for confirming safe-entry into the posterior segment if using current guidelines. The current cadaver-based paediatric guidelines safely avoid retinal injury.
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Corpo Ciliar/diagnóstico por imagem , Injeções Intravítreas , Esclera/efeitos da radiação , Esclerostomia , Transiluminação/métodos , Anestesia Geral , Pré-Escolar , Retinopatia Diabética/cirurgia , Feminino , Humanos , Lactente , Luz , Masculino , Microscopia Acústica , Estudos Prospectivos , Reprodutibilidade dos Testes , Vitrectomia , Hemorragia Vítrea/cirurgiaRESUMO
AIM: To assess the feasibility and efficacy of a streamlined single time-point 99mTc-HYNIC-Tyr3-octreotide (Tektrotyd) somatostatin receptor scintigraphy (SRS) protocol to differentiate pathological uptake by neuroendocrine tumours (NETs) from physiological activity. METHODS AND MATERIALS: Tektrotyd imaging in 50 consecutive patients with NETs was reviewed retrospectively. Imaging was independently assessed by two experienced reporters with dual-certification in radiology and nuclear medicine and agreed in consensus. The presence of physiological bowel activity and/or further sites of equivocal uptake on 4-hour planar imaging and whether combined single-photon-emission computed tomography (SPECT)/computed tomography (CT) assessment allowed accurate diagnosis was tabulated. A judgement was also made in each case on whether 2-hour planar imaging was necessary for accurate diagnostic interpretation. RESULTS: Thirty-six patients (72%) had positive findings on Tektrotyd SPECT/CT. Eight patients (16%) had bowel activity on 4-hour planar imaging, which could be considered to have hampered interpretation without access to SPECT/CT. Eleven studies in 10 patients (20%) demonstrated areas of indeterminate uptake on planar imaging; five in the uncinate process of the pancreas, three in the nasal cavity or paranasal sinuses, one in the adrenal glands, one in a focus of inflammation on the posterior abdominal wall, and one at the tip of a central venous line. In all cases, accurate interpretation of findings was possible with SPECT/CT, without the 2-hour planar image. CONCLUSION: Two-hour planar imaging could be safely omitted from Tektrotyd SRS incorporating SPECT/CT imaging without reducing the accuracy of diagnostic interpretation. Streamlined imaging has the potential to reduce patient inconvenience and improve scanner and staff efficiency.
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Tumores Neuroendócrinos/diagnóstico por imagem , Octreotida/análogos & derivados , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/métodos , Neoplasias Abdominais/diagnóstico por imagem , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos Clínicos , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Nasais/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias dos Seios Paranasais/diagnóstico por imagemRESUMO
AIM: To evaluate the efficacy of single time-point half-body (skull base to thighs) fluorine-18 choline positron emission tomography-computed tomography (PET-CT) compared to a triple-phase acquisition protocol in the detection of prostate carcinoma recurrence. MATERIALS AND METHODS: Consecutive choline PET-CT studies performed at a single tertiary referral centre in patients with biochemical recurrence of prostate carcinoma between September 2012 and March 2017 were reviewed retrospectively. The indication for the study, imaging protocol used, imaging findings, whether management was influenced by the PET-CT, and subsequent patient outcome were recorded. RESULTS: Ninety-one examinations were performed during the study period; 42 were carried out using a triple-phase protocol (dynamic pelvic imaging for 20 minutes after tracer injection, half-body acquisition at 60 minutes and delayed pelvic scan at 90 minutes) between 2012 and August 2015. Subsequently following interim review of diagnostic performance, a streamlined protocol and appropriate-use criteria were introduced. Forty-nine examinations were carried out using the single-phase protocol between 2015 and 2017. Twenty-nine (69%) of the triple-phase studies were positive for recurrence compared to 38 (78%) of the single-phase studies. Only one patient who had a single-phase study would have benefited from a dynamic acquisition, they have required no further treatment or imaging and are currently under prostate-specific antigen (PSA) surveillance. CONCLUSION: Choline PET-CT remains a useful tool for the detection of prostate recurrence when used in combination with appropriate-use criteria. Removal of dynamic and delayed acquisition phases reduces study time without adversely affecting accuracy. Benefits include shorter imaging time which improves patient comfort, reduced cost, and improved scanner efficiency.
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Colina/análogos & derivados , Recidiva Local de Neoplasia/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Neoplasias da Próstata/diagnóstico por imagem , Compostos Radiofarmacêuticos , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Próstata/diagnóstico por imagem , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
PURPOSE: To examine the relationship between retinal detachment and retrobulbar cysts in patients with optic nerve coloboma (ONC) and Morning Glory syndrome (MGS). METHODS: Patients diagnosed with either ONC or MGS were identified through a search of the Sick Kids database. Seventy-one patients either agreed to come in for a B-scan or had an incidental orbital B-scan or magnetic resonance imaging or both. Eyes with orbital B-scan ultrasound and/or magnetic resonance imaging images were assessed independently by two ophthalmologists and a radiologist for the presence of retrobulbar cysts. Retinal detachment was identified clinically with either indirect ophthalmoscopy or from fundus photographs. RESULTS: Forty-five of 71 (63%) and 26/71 (37%) patients had ONC and MGS, respectively. Retinal detachment occurred significantly more often in eyes with MGS than with ONC (9/17 [53%] vs. 5/45 [11%], P = 0.03, respectively). Retrobulbar cysts were not detected more often in MGS than in ONC (11/45 [24%] vs. 7/26 [27%]; P = 1.0). Eyes with retrobulbar cysts were significantly more likely to be associated with retinal detachment than those without (7/18 [39%] vs. 7/53 [13%]; P = 0.04). CONCLUSION: Retinal detachment occurs more frequently in MGS than in ONC in a cohort of patients referred to a specialist children's retinal service. Eyes with retrobulbar cysts are more likely to be associated with retinal detachment.
Assuntos
Coloboma/complicações , Disco Óptico/anormalidades , Doenças do Nervo Óptico/complicações , Nervo Óptico/anormalidades , Doenças Orbitárias/etiologia , Descolamento Retiniano/etiologia , Pré-Escolar , Cistos/etiologia , Feminino , Humanos , Incidência , Lactente , Masculino , Doenças do Nervo Óptico/epidemiologia , Doenças Orbitárias/epidemiologia , Descolamento Retiniano/epidemiologia , Estudos Retrospectivos , Fatores de RiscoRESUMO
The study evaluates use of Kollidon VA®64 and a combination of Kollidon VA®64 with Kollidon VA®64 Fine as excipient in direct compression process of tablets. The combination of the two grades of material is evaluated for capping, lamination and excessive friability. Inter particulate void space is higher for such excipient due to the hollow structure of the Kollidon VA®64 particles. During tablet compression air remains trapped in the blend exhibiting poor compression with compromised physical properties of the tablets. Composition of Kollidon VA®64 and Kollidon VA®64 Fine is evaluated by design of experiment (DoE). A scanning electron microscopy (SEM) of two grades of Kollidon VA®64 exhibits morphological differences between coarse and fine grade. The tablet compression process is evaluated with a mix consisting of entirely Kollidon VA®64 and two mixes containing Kollidon VA®64 and Kollidon VA®64 Fine in ratio of 77:23 and 65:35. A statistical modeling on the results from the DoE trials resulted in the optimum composition for direct tablet compression as combination of Kollidon VA®64 and Kollidon VA®64 Fine in ratio of 77:23. This combination compressed with the predicted parameters based on the statistical modeling and applying main compression force between 5 and 15 kN, pre-compression force between 2 and 3 kN, feeder speed fixed at 25 rpm and compression range of 45-49 rpm produced tablets with hardness ranging between 19 and 21 kp, with no friability, capping, or lamination issue.
Assuntos
Excipientes/química , Povidona/química , Comprimidos/química , Dureza , Tamanho da Partícula , Povidona/análise , Pressão , Solubilidade , Tecnologia FarmacêuticaRESUMO
Retinal vascular injury is a major cause of vision impairment in ischemic retinopathies. Insults such as hyperoxia, oxidative stress and inflammation contribute to this pathology. Previously, we showed that hyperoxia-induced retinal neurodegeneration is associated with increased polyamine oxidation. Here, we are studying the involvement of polyamine oxidases in hyperoxia-induced injury and death of retinal vascular endothelial cells. New-born C57BL6/J mice were exposed to hyperoxia (70% O2) from postnatal day (P) 7 to 12 and were treated with the polyamine oxidase inhibitor MDL 72527 or vehicle starting at P6. Mice were sacrificed after different durations of hyperoxia and their retinas were analyzed to determine the effects on vascular injury, microglial cell activation, and inflammatory cytokine profiling. The results of this analysis showed that MDL 72527 treatment significantly reduced hyperoxia-induced retinal vascular injury and enhanced vascular sprouting as compared with the vehicle controls. These protective effects were correlated with significant decreases in microglial activation as well as levels of inflammatory cytokines and chemokines. In order to model the effects of polyamine oxidation in causing microglial activation in vitro, studies were performed using rat brain microvascular endothelial cells treated with conditioned-medium from rat retinal microglia stimulated with hydrogen peroxide. Conditioned-medium from activated microglial cultures induced cell stress signals and cell death in microvascular endothelial cells. These studies demonstrate the involvement of polyamine oxidases in hyperoxia-induced retinal vascular injury and retinal inflammation in ischemic retinopathy, through mechanisms involving cross-talk between endothelial cells and resident retinal microglia.