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1.
Magn Reson Med ; 91(5): 2010-2027, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38098428

RESUMEN

PURPOSE: To develop a deep image prior (DIP) reconstruction for B1 + -corrected 2D cine MR fingerprinting (MRF). METHODS: The proposed method combines low-rank (LR) modeling with a DIP to generate cardiac phase-resolved parameter maps without motion correction, employing self-supervised training to enforce consistency with undersampled spiral k-space data. Two implementations were tested: one approach (DIP) for cine T1 , T2 , and M0 mapping, and a second approach (DIP with effective B1 + estimation [DIP-B1]) that also generated an effective B1 + map to correct for errors due to RF transmit inhomogeneities, through-plane motion, and blood flow. Cine MRF data were acquired in 14 healthy subjects and four reconstructions were compared: LR, low-rank motion-corrected (LRMC), DIP, and DIP-B1. Results were compared to diastolic ECG-triggered MRF, MOLLI, and T2 -prep bSSFP. Additionally, bright-blood and dark-blood images calculated from cine MRF maps were used to quantify ventricular function and compared to reference cine measurements. RESULTS: DIP and DIP-B1 outperformed other cine MRF reconstructions with improved noise suppression and delineation of high-resolution details. Within-segment variability in the myocardium (reported as the coefficient of variation for T1 /T2 ) was lowest for DIP-B1 (2.3/8.3%) followed by DIP (2.7/8.7%), LRMC (3.5/10.5%), and LR (15.3/39.6%). Spatial homogeneity improved with DIP-B1 having the lowest intersegment variability (2.6/4.1%). The mean bias in ejection fraction was -1.1% compared to reference cine scans. CONCLUSION: A DIP reconstruction for 2D cine MRF enabled cardiac phase-resolved mapping of T1 , T2 , M0 , and the effective B1 + with improved noise suppression and precision compared to LR and LRMC.


Asunto(s)
Corazón , Imagen por Resonancia Magnética , Humanos , Imagen por Resonancia Magnética/métodos , Corazón/diagnóstico por imagen , Miocardio , Procesamiento de Imagen Asistido por Computador/métodos , Voluntarios Sanos , Fantasmas de Imagen
2.
NMR Biomed ; 37(1): e5043, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37740596

RESUMEN

Late gadolinium enhancement (LGE) MRI is the non-invasive reference standard for identifying myocardial scar and fibrosis but has limitations, including difficulty delineating subendocardial scar and operator dependence on image quality. The purpose of this work is to assess the feasibility of generating multi-contrast synthetic LGE images from post-contrast T1 and T2 maps acquired using magnetic resonance fingerprinting (MRF). Fifteen consecutive patients with a history of prior ischemic cardiomyopathy (12 men; mean age 63  ±  13 years) were prospectively scanned at 1.5 T between Oct 2020 and May 2021 using conventional LGE and MRF after injection of gadolinium contrast. Three classes of synthetic LGE images were derived from MRF post-contrast T1 and T2 maps: bright-blood phase-sensitive inversion recovery (PSIR), black- and gray-blood T2 -prepared PSIR (T2 -PSIR), and a novel "tissue-optimized" image to enhance differentiation among scar, viable myocardium, and blood. Image quality was assessed on a 1-5 Likert scale by two cardiologists, and contrast was quantified as the mean absolute difference (MAD) in pixel intensities between two tissues, with different methods compared using Kruskal-Wallis with Bonferroni post hoc tests. Per-patient and per-segment scar detection rates were evaluated using conventional LGE images as reference. Image quality scores were highest for synthetic PSIR (4.0) and reference images (3.8), followed by synthetic tissue-optimized (3.3), gray-blood T2 -PSIR (3.0), and black-blood T2 -PSIR (2.6). Among synthetic images, PSIR yielded the highest myocardium/scar contrast (MAD = 0.42) but the lowest blood/scar contrast (MAD = 0.05), and vice versa for T2 -PSIR, while tissue-optimized images achieved a balance among all tissues (myocardium/scar MAD = 0.16, blood/scar MAD = 0.26, myocardium/blood MAD = 0.10). Based on reference mid-ventricular LGE scans, 13/15 patients had myocardial scar. The per-patient sensitivity/accuracy for synthetic images were the following: PSIR, 85/87%; black-blood T2 -PSIR, 62/53%; gray-blood T2 -PSIR, 100/93%; tissue optimized, 100/93%. Synthetic multi-contrast LGE images can be generated from post-contrast MRF data without additional scan time, with initial feasibility shown in ischemic cardiomyopathy patients.


Asunto(s)
Cardiomiopatías , Isquemia Miocárdica , Masculino , Humanos , Medios de Contraste , Gadolinio , Cicatriz/diagnóstico por imagen , Cicatriz/patología , Imagen por Resonancia Magnética/métodos , Miocardio/patología , Isquemia Miocárdica/diagnóstico por imagen , Isquemia Miocárdica/patología , Cardiomiopatías/diagnóstico por imagen , Cardiomiopatías/patología , Espectroscopía de Resonancia Magnética
3.
J Ultrasound Med ; 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38752367

RESUMEN

OBJECTIVES: Mercapto acetyl tri-glycine renogram (MAG3) scan has been the gold standard assessment of pediatric ureteropelvic junction obstruction (UPJO) but requires intravenous access and radiation exposure. While Doppler ultrasound measurements of resistive indices (RI) of the arcuate arteries have been proposed as an alternative assessment of obstruction, they have not been widely adopted in the pediatric population. We hypothesized that RI of the main renal artery (RA) is more strongly correlated with MAG3 findings than arcuate RI. METHODS: Pediatric patients with unilateral Society for Fetal Urology grade 3-4 hydronephrosis undergoing concomitant RUS and MAG3 were recruited. Doppler ultrasound peak systolic velocity (PSV); RI of bilateral RA at the origin, middle, and hilum; and RI of the superior, middle, and lower pole arcuate arteries were obtained. MAG3 differential renal function (DRF) and T½ were recorded. Differences in RI measurements (DRI) between the affected and normal kidney were calculated and compared with DRF and T½. RESULTS: 31 patients (median 4.6-month-old) were enrolled. Only RA RI at the origin differed between affected and normal kidneys (p < .001). DRI RA at the origin showed weak evidence for an association with MAG3 DRF < 40% (p .07). DRI was not associated with T½ > 20 minutes. CONCLUSION: There was weak evidence for an association between RA DRI at the origin and DRF but not with T½. These findings suggest that RA DRI may provide additional data in the evaluation of patients with UPJO to tailor the use of MAG3 and associated risk of radiation exposure to those patients most at risk for concomitant renal function impairment.

4.
J Urol ; 209(6): 1186-1193, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36821137

RESUMEN

PURPOSE: Although Children's Oncology Group renal tumor protocols mandate lymph node sampling during extirpative surgery for pediatric renal tumors, lymph node sampling is often omitted or low yield. Concerns over morbidity associated with extended lymph node sampling have led to hesitancy in adopting a formal lymph node sampling template. We hypothesized that complications in children undergoing lymph node sampling for renal tumors would be rare, and not associated with the number of lymph nodes sampled. MATERIALS AND METHODS: A single-institution, retrospective review of patients aged 0-18 years undergoing extirpative renal surgery with lymph node sampling for a suspected malignancy between 2005 and 2019 was performed. Patients with 0 or an unknown number of lymph nodes sampled or <150 days of follow-up were excluded. A "clinically significant" complication was defined as any Clavien complication ≥III, small-bowel obstruction, chylous ascites, organ injury, or wound infection. The number of lymph nodes sampled and its influence on the odds of experiencing a clinically significant complication was examined. RESULTS: A total of 144 patients met inclusion criteria. Median patient age was 38 months. Twenty-one patients (15%) had a clinically significant complication, the most common of which was ileus/small-bowel obstruction (n=16). In a multivariable analysis, increased lymph node yield was not found to influence the odds of experiencing a clinically significant complication (P = .6). CONCLUSIONS: In this cohort, there was no statistically significant difference in clinically significant complications in patients who underwent more extensive lymph node sampling during surgery for a suspected malignant pediatric renal tumor. Future studies on protocol adherence, staging accuracy, and survival trends using a lymph node sampling template in these patients should be performed.


Asunto(s)
Neoplasias Renales , Humanos , Niño , Neoplasias Renales/patología , Ganglios Linfáticos/cirugía , Ganglios Linfáticos/patología , Escisión del Ganglio Linfático/efectos adversos , Escisión del Ganglio Linfático/métodos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/patología , Estudios Retrospectivos , Estadificación de Neoplasias
5.
J Urol ; 209(3): 582-590, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36445021

RESUMEN

PURPOSE: The majority of children with unilateral renal masses suspicious for malignancy undergo radical nephrectomy, while nephron-sparing surgery is reserved for select cases. We investigated the impact of tumor size on the probability of histology. We hypothesized that pediatric small renal masses are more likely benign or non-Wilms tumor, thus potentially appropriate for nephron-sparing surgery. MATERIALS AND METHODS: The SEER (Surveillance, Epidemiology, and End Results) database was analyzed for patients aged 0-18 years diagnosed with a unilateral renal mass from 2000-2016. Statistical analysis was performed to help determine a tumor size cut point to predict Wilms tumor and assess the predictive value of tumor size on Wilms tumor histology. Additionally, a retrospective review was performed of patients 0-18 years old who underwent surgery for a unilateral renal mass at a single institution from 2005-2019. Statistical analysis was performed to assess the predictive value of tumor size on final histology. RESULTS: From the SEER analysis, 2,016 patients were included. A total of 1,672 tumors (82.9%) were Wilms tumor. Analysis revealed 4 cm to be a suitable cut point to distinguish non-Wilms tumor. Tumors ≥4 cm were more likely Wilms tumor (OR 2.67, P ≤ .001), but this was driven by the statistical significance in children 5-9 years old. From the institutional analysis, 134 patients were included. Ninety-seven tumors (72.3%) were Wilms tumor. Tumors ≥4 cm had higher odds of being Wilms tumor (OR 30.85, P = .001), malignant (OR 6.75, P = .005), and having radical nephrectomy-appropriate histology (OR 46.79, P < .001). CONCLUSIONS: The probability that a pediatric unilateral renal mass is Wilms tumor increases with tumor size. Four centimeters is a logical cut point to start the conversation around defining pediatric small renal masses and may help predict nephron-sparing surgery-appropriate histology.


Asunto(s)
Neoplasias Renales , Tumor de Wilms , Niño , Humanos , Recién Nacido , Lactante , Preescolar , Adolescente , Neoplasias Renales/cirugía , Neoplasias Renales/patología , Nefronas/cirugía , Nefronas/patología , Tumor de Wilms/cirugía , Nefrectomía/métodos , Estudios Retrospectivos
6.
J Med Internet Res ; 25: e46814, 2023 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-37713260

RESUMEN

BACKGROUND: Overcoming gender inequities is a global priority recognized as essential for improved health and human development. Gender-based violence (GBV) is an extreme manifestation of gender inequities enacted in real-world and internet-based environments. In Nigeria, GBV has come to the forefront of attention since 2020, when a state of emergency was declared due to increased reporting of sexual violence. Understanding GBV-related social narratives is important to design public health interventions. OBJECTIVE: We explore how gender-related internet-based conversations in Nigeria specifically related to sexual consent (actively agreeing to sexual behavior), lack of consent, and slut-shaming (stigmatization in the form of insults based on actual or perceived sexuality and behaviors) manifest themselves and whether they changed between 2017 and 2022. Additionally, we explore what role events or social movements have in shaping gender-related narratives in Nigeria. METHODS: Social listening was carried out on 12,031 social media posts (Twitter, Facebook, forums, and blogs) and almost 2 million public searches (Google and Yahoo search engines) between April 2017 and May 2022. The data were analyzed using natural language processing to determine the most salient conversation thematic clusters, qualitatively analyze time trends in discourse, and compare data against selected key events. RESULTS: Between 2017 and 2022, internet-based conversation about sexual consent increased 72,633%, from an average 3 to 2182 posts per month, while slut-shaming conversation (perpetrating or condemning) shrunk by 9%, from an average 3560 to 3253 posts per month. Thematic analysis shows conversation revolves around the objectification of women, poor comprehension of elements of sexual consent, and advocacy for public education about sexual consent. Additionally, posters created space for sexual empowerment and expressions of sex positivity, pushing back against others who weaponize posts in support of slut-shaming narrative. Time trend analysis shows a greater sense of empowerment in advocating for education around the legal age of consent for sexual activity, calling out double standards, and rejecting slut-shaming. However, analysis of emotions in social media posts shows anger was most prominent in sexual consent (n=1213, 73%) and slut-shaming (n=226, 64%) posts. Organic social movements and key events (#ArewaMeToo and #ChurchToo, the #SexforGrades scandal, and the #BBNaija television program) played a notable role in sparking discourse related to sexual consent and slut-shaming. CONCLUSIONS: Social media narratives are significantly impacted by popular culture events, mass media programs, social movements, and micro influencers speaking out against GBV. Hashtags, media clips, and other content can be leveraged effectively to spread awareness and spark conversation around evolving gender norms. Public health practitioners and other stakeholders including policymakers, researchers, and social advocates should be prepared to capitalize on social media events and discourse to help shape the conversation in support of a normative environment that rejects GBV in all its forms.


Asunto(s)
Violencia de Género , Femenino , Humanos , Nigeria , Comunicación , Narración , Internet
7.
Can J Neurol Sci ; 48(1): 127-129, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32646535

RESUMEN

Prospectively acquired Canadian cerebrospinal fluid samples were used to assess the performance characteristics of three ante-mortem tests commonly used to support diagnoses of Creutzfeldt-Jakob disease. The utility of the end-point quaking-induced conversion assay as a test for Creutzfeldt-Jakob disease diagnoses was compared to that of immunoassays designed to detect increased amounts of the surrogate markers 14-3-3γ and hTau. The positive predictive values of the end-point quaking-induced conversion, 14-3-3γ, and hTau tests conducted at the Prion Diseases Section of the Public Health Agency of Canada were 96%, 68%, and 66%, respectively.


Asunto(s)
Síndrome de Creutzfeldt-Jakob , Canadá , Síndrome de Creutzfeldt-Jakob/diagnóstico , Humanos , Valor Predictivo de las Pruebas , Estudios Prospectivos , Sensibilidad y Especificidad
8.
J Magn Reson Imaging ; 52(4): 1044-1052, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32222092

RESUMEN

BACKGROUND: Cardiac MR fingerprinting (cMRF) is a novel technique for simultaneous T1 and T2 mapping. PURPOSE: To compare T1 /T2 measurements, repeatability, and map quality between cMRF and standard mapping techniques in healthy subjects. STUDY TYPE: Prospective. POPULATION: In all, 58 subjects (ages 18-60). FIELD STRENGTH/SEQUENCE: cMRF, modified Look-Locker inversion recovery (MOLLI), and T2 -prepared balanced steady-state free precession (bSSFP) at 1.5T. ASSESSMENT: T1 /T2 values were measured in 16 myocardial segments at apical, medial, and basal slice positions. Test-retest and intrareader repeatability were assessed for the medial slice. cMRF and conventional mapping sequences were compared using ordinal and two alternative forced choice (2AFC) ratings. STATISTICAL TESTS: Paired t-tests, Bland-Altman analyses, intraclass correlation coefficient (ICC), linear regression, one-way analysis of variance (ANOVA), and binomial tests. RESULTS: Average T1 measurements were: basal 1007.4±96.5 msec (cMRF), 990.0±45.3 msec (MOLLI); medial 995.0±101.7 msec (cMRF), 995.6±59.7 msec (MOLLI); apical 1006.6±111.2 msec (cMRF); and 981.6±87.6 msec (MOLLI). Average T2 measurements were: basal 40.9±7.0 msec (cMRF), 46.1±3.5 msec (bSSFP); medial 41.0±6.4 msec (cMRF), 47.4±4.1 msec (bSSFP); apical 43.5±6.7 msec (cMRF), 48.0±4.0 msec (bSSFP). A statistically significant bias (cMRF T1 larger than MOLLI T1 ) was observed in basal (17.4 msec) and apical (25.0 msec) slices. For T2 , a statistically significant bias (cMRF lower than bSSFP) was observed for basal (-5.2 msec), medial (-6.3 msec), and apical (-4.5 msec) slices. Precision was lower for cMRF-the average of the standard deviation measured within each slice was 102 msec for cMRF vs. 61 msec for MOLLI T1 , and 6.4 msec for cMRF vs. 4.0 msec for bSSFP T2 . cMRF and conventional techniques had similar test-retest repeatability as quantified by ICC (0.87 cMRF vs. 0.84 MOLLI for T1 ; 0.85 cMRF vs. 0.85 bSSFP for T2 ). In the ordinal image quality comparison, cMRF maps scored higher than conventional sequences for both T1 (all five features) and T2 (four features). DATA CONCLUSION: This work reports on myocardial T1 /T2 measurements in healthy subjects using cMRF and standard mapping sequences. cMRF had slightly lower precision, similar test-retest and intrareader repeatability, and higher scores for map quality. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1 J. Magn. Reson. Imaging 2020;52:1044-1052.


Asunto(s)
Corazón , Imagen por Resonancia Magnética , Adolescente , Adulto , Voluntarios Sanos , Corazón/diagnóstico por imagen , Humanos , Espectroscopía de Resonancia Magnética , Persona de Mediana Edad , Fantasmas de Imagen , Estudios Prospectivos , Reproducibilidad de los Resultados , Adulto Joven
9.
Vascular ; 27(1): 78-89, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30501582

RESUMEN

BACKGROUND: Bivalirudin may be an effective alternative anticoagulant to heparin for use in percutaneous peripheral interventions. We aimed to compare the safety and efficacy of bivalirudin versus heparin as the procedural anticoagulant agent in patients undergoing percutaneous peripheral intervention. METHODS: For this meta-analysis and systematic review, we conducted a search in PubMed, Medline, Embase, and Cochrane for all the clinical studies in which bivalirudin was compared to heparin as the procedural anticoagulant in percutaneous peripheral interventions. Outcomes studied included all-cause mortality, all-bleeding, major and minor bleeding, and access site complications. RESULTS: Eleven studies were included in the analysis, totaling 20,137 patients. There was a significant difference favoring bivalirudin over heparin for all-cause mortality (risk ratio 0.58, 95% CI 0.39-0.87), all-bleeding (risk ratio 0.62, 95% CI 0.50-0.78), major bleeding (risk ratio 0.61, 95% CI 0.39-0.96), minor bleeding (risk ratio 0.66, 95% CI 0.47-0.92), and access site complications (risk ratio 0.66, 95% CI 0.51-0.84). There was no significant difference in peri-procedural need for blood transfusions (risk ratio 0.79, 95% CI 0.57-1.08), myocardial infarction (risk ratio 0.87, 95% CI 0.59-1.28), stroke (risk ratio 0.77, 95% CI 0.59-1.01), intracranial bleeding (risk ratio 0.77, 95% CI 0.29-2.02), or amputations (OR 0.75, 95% CI 0.53-1.05). CONCLUSION: Our meta-analysis suggests that bivalirudin use for percutaneous peripheral interventions is associated with lower all-cause mortality, bleeding, and access site complications as compared to heparin. Further large randomized trials are needed to confirm the current results.


Asunto(s)
Anticoagulantes/administración & dosificación , Antitrombinas/administración & dosificación , Cateterismo Periférico , Procedimientos Endovasculares , Heparina/administración & dosificación , Hirudinas/administración & dosificación , Fragmentos de Péptidos/administración & dosificación , Enfermedad Arterial Periférica/terapia , Trombosis/prevención & control , Anciano , Anticoagulantes/efectos adversos , Antitrombinas/efectos adversos , Cateterismo Periférico/efectos adversos , Cateterismo Periférico/mortalidad , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/mortalidad , Femenino , Hemorragia/inducido químicamente , Heparina/efectos adversos , Hirudinas/efectos adversos , Humanos , Masculino , Fragmentos de Péptidos/efectos adversos , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/efectos adversos , Medición de Riesgo , Factores de Riesgo , Trombosis/etiología , Trombosis/mortalidad , Resultado del Tratamiento
10.
Pediatr Surg Int ; 35(9): 1005-1008, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31278478

RESUMEN

PURPOSE: The literature about ectopic ureters in anorectal malformations is limited. Repair of an anorectal malformation may require dissection near the normal or abnormal insertion of the ureters. Knowledge of the presence and location of ectopic ureters may prevent intraoperative injury. We aim to describe the incidence and location of ectopic ureters in patients with anorectal malformations and to characterize associated renal anomalies. METHODS: This is an IRB-approved retrospective study of patients with anorectal malformations and ectopic ureters identified in our colorectal database. RESULTS: Of 2283 patients with anorectal malformation, 79 (3.5%) had ectopic ureter(s). Of those, 29% had bilateral ectopic ureters. Nearly all (87%) of bilateral ectopic ureters occurred in females. Ectopic ureters most commonly inserted into the bladder neck (33%), vagina (15%), or urethra (13%). Renal dysfunction was noted in a high proportion of patients. The majority (59%) of ectopic ureters were associated with dysfunction of the ipsilateral kidney. Interestingly, 29% of patients with unilateral ureteral ectopia had an abnormal contralateral kidney. Only 22 patients (28%) had two normal kidneys, and 5 (6%) had documented renal failure with 2 (2.5%) requiring renal transplant. This compares to a transplant rate of 0.6% among anorectal malformation patients without ectopic ureter. CONCLUSIONS: The incidence of ectopic ureter is 3.5% among anorectal malformation patients. Cloaca and recto-bladder neck fistula are the types of anorectal malformation with higher incidence. Ureteral ectopia seems to confer an increased risk of renal failure. Identifying ectopic ureters is important for surgical planning and monitoring renal function vigilantly.


Asunto(s)
Malformaciones Anorrectales/cirugía , Uréter/anomalías , Preescolar , Bases de Datos Factuales , Femenino , Humanos , Riñón/anomalías , Masculino , Estudios Retrospectivos
12.
Echocardiography ; 35(11): 1872-1877, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30324627

RESUMEN

Most common congenital anatomical abnormalities of the subvalvular apparatus (papillary muscles and chordae tendineae) are parachute or parachute like mitral valve. This is more commonly reported among the pediatric population as they develop heart failure symptoms shortly after birth. Reports of adult cases are rare and incidental. Multimodality imaging has an important role in evaluating such anatomical abnormalities, and identification of possible related complications. We are describing a rare atypical variant of parachute like mitral valve.


Asunto(s)
Angiografía por Tomografía Computarizada/métodos , Ecocardiografía/métodos , Electrocardiografía/métodos , Cardiopatías Congénitas/diagnóstico por imagen , Músculos Papilares/anomalías , Músculos Papilares/diagnóstico por imagen , Adulto , Humanos , Masculino
13.
BMC Urol ; 17(1): 26, 2017 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-28381270

RESUMEN

BACKGROUND: Ureteral herniations are a rare occurrence, generally found incidentally on cross sectional imaging or during surgical intervention for unrelated processes. Several locations of ureteral herniations can occur including the inguinal, femoral, sciatic, obturator, and thoracic regions. While few reports of ureteral hernias are reported in the literature overall, the vast majority of those reported are inguinoscrotal herniations found during evaluation and treatment of inguinal hernias. Pelvic outlet ureteral herniations intrinsically are more common secondary to their dependent locations. Intrathoracic ureteral herniations through diaphragmatic defects are an exceptionally rare subset of ureteral herniations and have only been described sparingly. Fewer than ten case reports of diaphramatic ureteral herniations have been reported and none have described both cystoscopic management and open reconstruction. CASE PRESENTATION: We report the case of a 81 year old female with flank pain who was found to have idiopathic diaphragmatic hernia with incarcerated proximal ureter. She had no prior injury or surgery that explained her clinical presentation. She was initially observed and then managed conservatively with ureteral stent exchanges. Ultimately she underwent open surgical repair of her diaphragmatic hernia, reduction, resection and anastomosis of redundant proximal incarcerated ureteral segment, and nephropexy for a hypermobile right renal unit. This case report illustrates the pre- and post-operative imaging studies of a very rare intrathoracic ureteral herniation as well as surgical approach to repair. CONCLUSION: A herniated ureter is a potential source of serious renal and ureteral complications. The thoracic herniation of ureter is the rarest of the ureteral herniations. When discovered, they should be managed to preserve renal function and prevent strangulation of the affected segment of ureter. This case report documents the treatment of a thoracic ureteral herniation with observation, conservative endoscopic management, and finally open surgical reconstruction.


Asunto(s)
Hernia Diafragmática/cirugía , Uréter/cirugía , Enfermedades Ureterales/cirugía , Anciano de 80 o más Años , Endoscopía , Femenino , Hernia Diafragmática/complicaciones , Hernia Diafragmática/diagnóstico por imagen , Humanos , Tomografía Computarizada por Rayos X , Uréter/diagnóstico por imagen , Enfermedades Ureterales/diagnóstico por imagen , Obstrucción Ureteral/diagnóstico por imagen , Obstrucción Ureteral/etiología
14.
Chemistry ; 22(7): 2466-72, 2016 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-26751824

RESUMEN

Efficient reactions between fluorine-functionalised biphenyl and terphenyl derivatives with catechol-functionalised terminal groups provide a route to large, discrete organic molecules of intrinsic microporosity (OMIMs) that provide porous solids solely by their inefficient packing. By altering the size and substituent bulk of the terminal groups, a number of soluble compounds with apparent BET surface areas in excess of 600 m(2) g(-1) are produced. The efficiency of OMIM structural units for generating microporosity is in the order: propellane>triptycene>hexaphenylbenzene>spirobifluorene>naphthyl=phenyl. The introduction of bulky hydrocarbon substituents significantly enhances microporosity by further reducing packing efficiency. These results are consistent with findings from previously reported packing simulation studies. The introduction of methyl groups at the bridgehead position of triptycene units reduces intrinsic microporosity. This is presumably due to their internal position within the OMIM structure so that they occupy space, but unlike peripheral substituents they do not contribute to the generation of free volume by inefficient packing.

15.
Eur Radiol ; 26(10): 3626-34, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26809292

RESUMEN

OBJECTIVES: With increasing use of prospective scanning techniques for cardiac computed tomography (CT), meaningful evaluation of chamber volumes is no longer possible due to lack of normal values. We aimed to define normal values for mid-diastolic (MD) chamber volumes and to determine their significance in comparison to maximum volumes. METHODS: Normal ranges at MD for left ventricular (LV) volume and mass and left atrial (LA) volume were determined from 101 normal controls. Thereafter, 109 consecutive CT scans, as well as 21 post-myocardial infarction patients, were analysed to determine the relationship between MD and maximum volumes. RESULTS: MD volumes correlated closely with maximal volumes (r = 0.99) for both LV and LA, and could estimate maximum volumes accurately. LV mass, measured at ED or MD, were very similar (r = 0.99). Abnormal MD volumes had excellent sensitivity and specificity to detect chamber enlargement based on maximal volumes (LV 86 %, 100 %, respectively; LA 100 %, 92 %, respectively). CONCLUSION: A single MD phase can identify patients with cardiomegaly or LV hypertrophy with a high degree of accuracy and MD volumes can give an accurate estimate of maximum LV and LA volumes. KEY POINTS: • Traditionally, helical cardiac CT provided clinically important information from chamber volume analysis. • Mid-diastolic left atrial and ventricular volumes correlate closely with maximal volumes. • We derive normal values for mid-diastolic left atrial and ventricular volumes and mass. • A single mid-diastolic phase can be used to identify chamber enlargement and hypertrophy.


Asunto(s)
Angiografía por Tomografía Computarizada/métodos , Angiografía Coronaria/métodos , Infarto del Miocardio/fisiopatología , Adulto , Anciano , Diástole/fisiología , Femenino , Atrios Cardíacos/fisiopatología , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico por imagen , Variaciones Dependientes del Observador , Estudios Prospectivos , Valores de Referencia , Sensibilidad y Especificidad , Volumen Sistólico , Sístole/fisiología , Función Ventricular Izquierda/fisiología
16.
J Phys Chem A ; 119(10): 1830-7, 2015 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-25686211

RESUMEN

The self-recombination reaction of (•)CH2OH radicals in neutral aqueous solution has been studied at temperatures up to 300 °C at a pressure of 220 bar using pulse radiolysis and transient absorption. (•)CH2OH species decay by second-order kinetics independent of the applied dose, with a rate constant at 22 °C of 2k = 1.4 ± 0.1 × 10(9) M(-1) s(-1). The recombination follows Arrhenius behavior with the activation energy (E(a)) 12.7 ± 0.9 kJ/mol and pre-exponential factor of 1.9 ± 0.4 × 10(11) M(-1) s(-1). The overall recombination is significantly slower than the diffusion limit at elevated temperature, meaning that both disproportionation and dimerization channels have significant activation barriers. Ab initio calculations support the inference that the dimerization channel has no energy barrier, but has a large negative activation entropy barrier. The disproportionation channel (giving aqueous formaldehyde) almost certainly involves one or more specific water molecules to lower its activation energy relative to the gas phase.

17.
J Phys Chem A ; 119(34): 9148-59, 2015 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-26275103

RESUMEN

Since its discovery over 50 years ago, the "structure" and properties of the hydrated electron have been a subject for wonderment and also fierce debate. In the present work we seriously explore a minimal model for the aqueous electron, consisting of a small water anion cluster embedded in a polarized continuum, using several levels of ab initio calculation and basis set. The minimum energy "zero Kelvin" structure found for any 4-water (or larger) anion cluster, at any post-Hartree­Fock theory level, is very similar to a recently reported embedded-DFT-in-classical-water-MD simulation (Uhlig, Marsalek, and Jungwirth, J. Phys. Chem. Lett. 2012, 3, 3071−3075), with four OH bonds oriented toward the maximum charge density in a small central "void". The minimum calculation with just four water molecules does a remarkably good job of reproducing the resonance Raman properties, the radius of gyration derived from the optical spectrum, the vertical detachment energy, and the hydration free energy. For the first time we also successfully calculate the EPR g-factor and (low temperature ice) hyperfine couplings. The simple tetrahedral anion cluster model conforms very well to experiment, suggesting it does in fact represent the dominant structural motif of the hydrated electron.


Asunto(s)
Electrones , Teoría Cuántica , Agua/química , Enlace de Hidrógeno , Conformación Molecular , Simulación de Dinámica Molecular , Rotación , Termodinámica
18.
Am J Cardiol ; 190: 48-53, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36563458

RESUMEN

The American College of Cardiology and the American Heart Association guidelines recommend treatment of patients with severe hypercholesterolemia (low-density lipoprotein cholesterol [LDL-C] ≥190 mg/100 ml) with a high-intensity statin. However, atherosclerotic cardiovascular disease (ASCVD) risk, even among those with severe hypercholesterolemia, is heterogeneous, and coronary artery calcium (CAC) scoring may be used to clarify risk. We sought to evaluate CAC in patients with severe hypercholesterolemia and measure its impact on real-world statin prescriptions. We identified patients with at least 1 LDL-C ≥190 mg100 ml who had a CAC scoring in the Community Benefit of No-Charge Calcium Score Screening Program (CLARIFY) study (NCT04075162) between 2014 and 2020. We explored the CAC distribution, factors associated with CAC >0, and ASCVD risk (myocardial infarction, stroke, revascularization, death). A total of 1,904 patients (1.257 women, aged 57.8 ± 9.3 years) with severe hypercholesterolemia were included. LDL-C ranged from 190 to 524 mg100 ml (mean 215.5 ± 27 mg100 ml). A total of 864 patients (45.4%) had CAC = 0 and 1,561 (82%) had CAC <100. In patients with LDL-C ≥250 mg100 ml, 67 (36.6%) had CAC = 0. Age, male gender, smoking, diabetes, systolic blood pressure, and obesity (ps ≤0.001) were associated with CAC >0. In patients with LDL-C ≥190 mg100 ml, CAC was associated with a higher risk for ASCVD events (CAC ≥100 vs CAC <100, hazard ratio 3.57 [1.81 to 7.04], p <0.001). A higher CAC category was associated with increased statin use after CAC scoring (p <0.001). In patients with severe hypercholesterolemia, 45% had CAC = 0, which was associated with a significantly lower ASCVD risk. CAC was associated with statin prescription and cholesterol lowering. In conclusion, CAC scoring may be used to clarify ASCVD risk in this heterogeneous population with severe hypercholesterolemia.


Asunto(s)
Aterosclerosis , Enfermedad de la Arteria Coronaria , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Hipercolesterolemia , Humanos , Masculino , Femenino , Estados Unidos/epidemiología , Hipercolesterolemia/complicaciones , Hipercolesterolemia/tratamiento farmacológico , Hipercolesterolemia/epidemiología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Enfermedad de la Arteria Coronaria/complicaciones , Calcio , LDL-Colesterol , Medición de Riesgo , Aterosclerosis/epidemiología , Colesterol , Factores de Riesgo
19.
Alcohol Clin Exp Res ; 36(4): 625-32, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21995416

RESUMEN

BACKGROUND: Oxidative stress has been proposed as one of the mechanisms of alcohol-induced brain shrinkage and alcohol-induced hepatotoxicity. The aim of this study was to assess the correlations between liver function and brain volume (BV) measurements in patients with alcohol dependence. METHODS: We recruited 124 patients with alcohol dependence and 111 healthy control subjects from National Institute of Health, National Institute on Alcohol Abuse and Alcoholism inpatient alcohol treatment program. Gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), as well as hematocrit (Hct) and albumin were assayed shortly after admission. Magnetic resonance imaging examination was conducted in both groups (after 3-week abstinence in the patient group). We used stepwise linear regression analyses to determine the variables most strongly correlated with brain shrinkage. RESULTS: Patients with alcohol dependence had lower BV, and greater brain shrinkage as measured by gray matter ratio (GMR), white matter ratio (WMR), brain ratio (BR), and higher cerebrospinal fluid ratio ratio (CSFR) compared with their healthy counterparts. Age and sex were significantly correlated with some BV measurements in both patient and control groups. Body mass index (BMI) was significantly correlated with CSFR, BR, GMR, and WMR; Hct with CSFR and BR; serum GGT level with BV, CSFR, BR, GMR, and WMF in the patient group. No biological variables were correlated with BV indices in the control group. In gender-stratified analysis, age was significantly correlated with brain shrinkage in male patients but not in female patients. Serum GGT level in male and female patients, Hct in male patients, and AST levels in female patients were significantly correlated with brain shrinkage. CONCLUSIONS: Our results showed that the higher levels of liver function indices, especially GGT, correlated with BV shrinkage as measured using CSFR, BR, GMR, and WMR in patients with alcohol dependence but not in controls. Serum GGT level outweighed aging effect on brain shrinkage in female patients.


Asunto(s)
Alcoholismo/patología , Alcoholismo/fisiopatología , Encéfalo/patología , Hígado/fisiopatología , Edad de Inicio , Anciano , Envejecimiento/fisiología , Alcoholismo/líquido cefalorraquídeo , Índice de Masa Corporal , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Escolaridad , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Lineales , Pruebas de Función Hepática , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Caracteres Sexuales , Fumar/epidemiología , Factores Socioeconómicos
20.
Echocardiography ; 29(6): 735-41, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22404245

RESUMEN

BACKGROUND: With recent advances in multimodality cardiac imaging, a number of methods exist for the noninvasive assessment of aortic disease. Although multidetector row computed tomography (MDCT) remains the gold standard for aortic measurements, there are a number of limitations including radiation and contrast-induced nephropathy. Transthoracic echocardiography (TTE) is an alternative to MDCT for providing accurate anatomic assessment of aortic root and ascending aorta dimensions. OBJECTIVES AND METHODS: To determine the accuracy of two-dimensional (2D) TTE for determining aortic measurements in comparison to MDCT, a retrospective study of individuals with varying aortic root and ascending aorta dimensions was performed. RESULTS: There were 116 patients (77 males, mean age 49 ± 12 years) in total. The maximum aortic diameters by 2D TTE were 26.1 ± 4.3 mm (annulus), 32.4 ± 5.6 mm (sinuses), 30.1 ± 5.9 mm (sinotubular [ST] junction), and 33.4 ± 7.3 mm (ascending aorta). The maximum aortic diameters by MDCT were 30.1 ± 4.1 mm (annulus), 35.8 ± 5.8 mm (sinuses), 33.2 ± 5.9 mm (ST junction), and 37.4 ± 7.6 mm (ascending aorta). There was good to excellent correlation between 2D TTE and MDCT at all four levels of the aorta (annulus: r = 0.84; sinuses: r = 0.93; ST junction: r = 0.93; ascending aorta: r = 0.88). There was a consistent underestimation of aortic measurements obtained by 2D TTE when compared to MDCT. CONCLUSION: 2DTTE is a feasible, accurate, and reproducible method for the noninvasive assessment of thoracic aortic diameters as compared to MDCT.


Asunto(s)
Algoritmos , Aorta/diagnóstico por imagen , Aortografía/métodos , Ecocardiografía/métodos , Interpretación de Imagen Asistida por Computador/métodos , Técnica de Sustracción , Tomografía Computarizada por Rayos X/métodos , Femenino , Humanos , Aumento de la Imagen/métodos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
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