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1.
Dig Dis Sci ; 69(4): 1135-1142, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38383939

RESUMEN

INTRODUCTION: The aim of this study is to estimate the global burden of pancreatic cancer from 1990 to 2019. METHODS: We reconstructed the Global Burden of Diseases (GBD) study results for pancreatic cancer across 204 countries and territories. Our study generated estimates for key disease burden indicators, including incidence, prevalence, mortality, and disability-adjusted life years (DALYs), and cost. Linear regression analysis of the natural logarithm of age-standardized outcomes was used to calculate annual percent change. RESULTS: In 2019, there were a total of 530,296 incident and 442,101 prevalent cases of pancreatic cancer, resulting in 531,107 deaths and 11.5 million DALYs lost. The age-standardized incidence and prevalence of pancreatic cancer has increased from 5.22 (95% CI 4.97-5.40) to 6.57 (CI 6.00-7.09) per 100,000 people per year, and 4.1 (95% CI 3.95-4.26) to 5.4 (CI 4.96-5.87), respectively. This equated to 10 million (95% CI 9.5 to 10.4 million) incident cases of pancreatic cancer. The number of DALYs lost as a result of pancreatic cancer was 225 million years (95% CI 216-234 million years). Mortality from pancreatic cancer increased over the study period from 3.7 (95% CI 3.54-3.83) to 6.9 (95% CI 6.36-7.32). Incidence, prevalence, DALYs, and mortality were higher in countries with a higher socio-demographic index. CONCLUSIONS: Pancreatic cancer is rising around the world and is associated with a high economic burden. Programs aimed at reducing modifiable risk factors are needed.


Asunto(s)
Carga Global de Enfermedades , Neoplasias Pancreáticas , Humanos , Años de Vida Ajustados por Calidad de Vida , Factores de Riesgo , Incidencia , Factores Socioeconómicos , Salud Global
2.
Neuroradiology ; 64(9): 1747-1754, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35333949

RESUMEN

PURPOSE: Brain herniation into arachnoid granulations (BHAG) of the dural venous sinuses is a recently described finding of uncertain etiology. The purpose of this study was to investigate the prevalence of BHAG in a cohort of patients with pulsatile tinnitus (PT) and to clarify the physiologic and clinical implications of these lesions. METHODS: The imaging and charts of consecutive PT patients were retrospectively reviewed. All patients were examined with MRI including pre- and post-contrast T1- and T2-weighted sequences. Images were reviewed separately by three blinded neuroradiologists to identify the presence of BHAG. Their location, signal intensity, size, presence of arachnoid granulation, and associated dural venous sinus stenosis were documented. Clinical records were further reviewed for idiopathic intracranial hypertension, history of prior lumbar puncture, and opening pressure. RESULTS: Two hundred sixty-two consecutive PT patients over a 4-year period met inclusion criteria. PT patients with BHAG were significantly more likely to have idiopathic intracranial hypertension than PT patients without BHAG (OR 4.2, CI 1.5-12, p = 0.006). Sixteen out of 262 (6%) patients were found to have 18 BHAG. Eleven out of 16 (69%) patients had unilateral temporal or occipital lobe herniations located in the transverse sinus or the transverse-sigmoid junction. Three out of 16 (19%) patients had unilateral cerebellar herniations and 2/16 (13%) patients had bilateral BHAG. CONCLUSION: In patients with PT, BHAG is a prevalent MRI finding that is strongly associated with the clinical diagnosis of IIH. The pathogenesis of BHAG remains uncertain, but recognition should prompt comprehensive evaluation for IIH.


Asunto(s)
Encefalopatías , Hipertensión Intracraneal , Seudotumor Cerebral , Acúfeno , Aracnoides/diagnóstico por imagen , Aracnoides/patología , Encéfalo/patología , Encefalopatías/patología , Senos Craneales/diagnóstico por imagen , Senos Craneales/patología , Encefalocele/complicaciones , Encefalocele/diagnóstico por imagen , Encefalocele/epidemiología , Humanos , Hipertensión Intracraneal/complicaciones , Prevalencia , Seudotumor Cerebral/complicaciones , Seudotumor Cerebral/diagnóstico por imagen , Seudotumor Cerebral/patología , Estudios Retrospectivos , Acúfeno/patología
3.
AJR Am J Roentgenol ; 216(6): 1626-1633, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-32876481

RESUMEN

Dural arteriovenous fistulas (DAVFs) are high-flow acquired shunts that can carry high risk of intracranial hemorrhage. Because DAVFs can often be managed by endovascular means, early and accurate diagnosis can markedly improve patient morbidity. Time-of-flight and arterial spin-labeling MRA have increased the diagnostic utility of MRI for DAVF by showing hemodynamic rather than anatomic evidence of shunting. The purpose of this article is to describe the cases of seven patients who had co-localization of arterial spin-labeling signal intensity and time-of-flight flow-related enhancement in the left skull base, resulting in a misdiagnosis of DAVF and a recommendation for catheter angiography by the interpreting radiologist. Benign jugular venous reflux is identified as a common mechanism in each case, and the physiology behind this imaging pitfall is described. An algorithmic diagnostic approach to differentiating physiologic venous reflux from true posterior skull base DAVFs is presented.


Asunto(s)
Malformaciones Vasculares del Sistema Nervioso Central/diagnóstico por imagen , Venas Yugulares/diagnóstico por imagen , Venas Yugulares/fisiopatología , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Anciano de 80 o más Años , Encéfalo/diagnóstico por imagen , Malformaciones Vasculares del Sistema Nervioso Central/fisiopatología , Diagnóstico Diferencial , Femenino , Humanos , Angiografía por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad
4.
Stroke ; 51(10): 2990-2996, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32912090

RESUMEN

BACKGROUND AND PURPOSE: Do children have an increased risk for brain arteriovenous malformation (AVM) recurrence compared with adults and does this risk vary depending on initial presentation with AVM rupture? METHODS: We retrospectively studied 115 patients initially presenting with brain AVM under age 25 years who underwent complete surgical resection of the AVM as documented by digital subtraction angiography (DSA) and had delayed follow-up DSA to evaluate for AVM recurrence after apparent initial cure. RESULTS: The mean time from baseline DSA to follow-up DSA was 2.3 years, ranging from 0 to 15 years. Twelve patients (10.4% of the 115 patient cohort and 16.7% of 72 patients with hemorrhage at initial presentation) demonstrated AVM recurrence on follow-up DSA. All patients with recurrence initially presented with intracranial hemorrhage, and intracranial hemorrhage was a significant predictor of recurrence (log rank P=0.037). Among patients with initial hemorrhage, the 5-year recurrence rate was 17.8% (95% CI, 8.3%-35.7%). All recurrences occurred in patients who were children at the time of their initial presentation; the oldest was 15 years of age at the time of initial AVM surgery. The 5-year recurrence rate for children (0-18 years of age) with an initial presentation of hemorrhage was 21.4% (95% CI, 10.1%-41.9%). Using Cox regression, we found the risk of AVM recurrence decreased by 14% per each year increase in age at the time of initial surgical resection (hazard ratio=0.86 [95% CI, 0.75-0.99]; P=0.031). CONCLUSIONS: There is a high rate of recurrence of apparently cured brain AVMs in children who initially present with AVM rupture. Imaging follow-up is warranted to prevent re-rupture.


Asunto(s)
Fístula Arteriovenosa/cirugía , Encéfalo/cirugía , Malformaciones Arteriovenosas Intracraneales/cirugía , Adolescente , Angiografía de Substracción Digital , Fístula Arteriovenosa/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Niño , Preescolar , Femenino , Humanos , Malformaciones Arteriovenosas Intracraneales/diagnóstico por imagen , Masculino , Microcirugia , Procedimientos Neuroquirúrgicos , Recurrencia , Estudios Retrospectivos , Rotura/cirugía , Resultado del Tratamiento , Adulto Joven
5.
Interv Neuroradiol ; : 15910199231188257, 2023 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-37552935

RESUMEN

Dural arteriovenous fistulas with drainage into the spinal veins, classified as Cognard type 5, can be challenging to diagnose and treat. Brainstem and cervical spinal cord signal abnormalities on magnetic resonance imaging result from venous congestion, and can mimic tumor, infection, or inflammation.1-3 Transarterial and transvenous embolization techniques can be used to treat dural arteriovenous fistulas endovascularly. Efficacious transvenous treatment relies on the ability to safely catheterize the draining vein at the dural arteriovenous fistula site. Transvenous access options may seem limited in the setting of occluded venous sinuses. This case highlights the technical aspects of the transvenous approach to embolization of a transverse-sigmoid sinus dural arteriovenous fistula within an isolated sinus,4,5 demonstrating traversal of the occluded venous sinus from a contralateral approach.6,7[Media: see text].

6.
J Neurointerv Surg ; 15(9): 931, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35977819

RESUMEN

Percutaneous sclerotherapy is an effective technique for treating lymphatic malformations of the head and neck, with clinical success rates exceeding 84%.1 Sodium tetradecyl, which damages lipid membranes and stimulates free radical-induced local damage, and doxycycline, which inhibits angiogenesis, have emerged as the safest and most effective of several available sclerosants.2-4 Although severe periprocedural morbidity is rare, temporary local complications are reported in 14% and skin necrosis or scarring in up to 0.8-5.8% of sclerotherapy procedures.5 As these lesions are frequently located in the face and/or neck, even minor complications can be disfiguring and must be avoided. This technical video describes a 'dual-agent' approach for percutaneous sclerotherapy of macrocystic lymphatic malformations using sodium tetradecyl as a 'primer' followed by doxycycline as a definitive sclerosant (video 1). This technique emphasizes meticulous backtable preparation and effective use of ultrasound and fluoroscopy to minimize complications. neurintsurg;15/9/931/V1F1V1Video 1 .


Asunto(s)
Anomalías Linfáticas , Malformaciones Vasculares , Humanos , Escleroterapia/métodos , Doxiciclina/uso terapéutico , Resultado del Tratamiento , Estudios Retrospectivos , Soluciones Esclerosantes/uso terapéutico , Anomalías Linfáticas/diagnóstico por imagen , Anomalías Linfáticas/terapia , Sodio
7.
Interv Neuroradiol ; : 15910199231154689, 2023 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-36760130

RESUMEN

BACKGROUND AND PURPOSE: Pediatric neurointerventional radiology is an evolving subspecialty with growing indications and technological advancement such as miniaturization of devices and decreased radiation dose. The ability to perform these procedures is continuously balanced with necessity given the inherently higher risks of radiation and cerebrovascular injury in infants. The purpose of this study is to review our institution's neurointerventional experience in infants less than one year of age to elucidate trends in this patient population. METHODS: We retrospectively identified 132 patients from a neurointerventional database spanning 25 years (1997-2022) who underwent 226 procedures. Treatment type, indication, and location as well as patient demographics were extracted from the medical record. RESULTS: Neurointerventional procedures were performed as early as day of life 0 in a patient with an arteriovenous shunting malformation. Average age of intervention in the first year of life is 5.9 months. Thirty-eight of 226 procedures were completed in neonates. Intra-arterial chemotherapy (IAC) for the treatment of retinoblastoma comprised 36% of neurointerventional procedures completed in infants less than one year of age followed by low flow vascular malformations (21.2%), vein of Galen malformations (11.5%), and dural arteriovenous fistulas (AVF) (9.3%). Less frequent indications include non-Galenic pial AVF (4.4%) and tumor embolization (3.0%). The total number of interventions has increased secondary to the onset of retinoblastoma treatment in 2010 at our institution. CONCLUSION: The introduction of IAC for the treatment of retinoblastoma in the last decade is the primary driver for the increased trend in neurointerventional procedures completed in infants from 1997 to 2022.

8.
J Neurointerv Surg ; 15(12): 1242-1246, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36414388

RESUMEN

BACKGROUND: Percutaneous sclerotherapy is an effective treatment for lymphatic malformations (LM) of the head and neck in adults. The purpose of this study was to examine the indications and efficacy of sclerotherapy for head/neck LM in the neonate and infant population. METHODS: We retrospectively reviewed patients treated with percutaneous sclerotherapy for LM of the head/neck at age ≤12 months at a single vascular anomalies clinic. The clinical, anatomic, and technical aspects of each treatment, complications, and post-treatment clinical and imaging outcomes were analyzed. RESULTS: 22 patients underwent 36 treatments during the first year of life. Median age at first treatment was 6.2 months (range 2-320 days). Severe airway compromise was the most frequent indication for treatment (31.8%). Sclerosants included doxycycline (80.5%), sodium tetradecyl sulfate (55.5%), bleomycin (11.1%) and ethanol (2.8%). There were no immediate procedure-related complications; sclerosant-related laboratory complications included transient metabolic acidosis (8.3%) and hemolytic anemia (5.5%). Median follow-up was 3.7 years (IQR 0.6-4.8). 47.6% of patients showed >75% lesion size reduction and 19.0% showed minimal response (<25% improvement). At last follow-up, 71.4% of children were developmentally normal and asymptomatic, 23.8% had recurring symptoms, and 4.8% required permanent tracheostomy. Patients with ongoing symptoms or limited response to percutaneous sclerotherapy (33.3%) were treated with long-term sirolimus. CONCLUSIONS: Percutaneous sclerotherapy is a safe and effective treatment for symptomatic LM of the head and neck in neonates and infants. Treatment strategy and management of recurrent symptoms requires consensus from an experienced, multidisciplinary team.


Asunto(s)
Anomalías Linfáticas , Malformaciones Vasculares , Niño , Recién Nacido , Adulto , Lactante , Humanos , Escleroterapia/efectos adversos , Escleroterapia/métodos , Estudios Retrospectivos , Cabeza/diagnóstico por imagen , Cuello , Soluciones Esclerosantes/efectos adversos , Anomalías Linfáticas/diagnóstico por imagen , Anomalías Linfáticas/terapia , Resultado del Tratamiento
9.
J Neurointerv Surg ; 16(1): 94-100, 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-36922033

RESUMEN

BACKGROUND: Pediatric spinal arteriovenous shunts (SAVS) are rare lesions with heterogeneous pathogenesis and clinical manifestations. OBJECTIVE: To evaluate the clinical characteristics, angioarchitecture, and technical/clinical outcomes in SAVS through a large single-center cohort analysis and meta-analysis of individual patient data. METHODS: A retrospective institutional database identified children (aged 0-21 years) who underwent digital subtraction spinal angiography (DSA) for SAVS between January 1996 and July 2021. Clinical data were recorded to evaluate angioarchitecture, generate modified Aminoff-Logue gait disturbance scores (AL) and McCormick grades (MC), and assess outcomes. We then performed a systematic literature review following PRISMA-IPD (Preferred Reporting Items for Systematic Reviews and Meta-Analyses for individual patient data) guidelines, extracting similar data on individual patients for meta-analysis. RESULTS: The cohort consisted of 28 children (M:F=11:17) with 32 SAVS lesions, with a mean age of 12.8±1.1 years at diagnosis. At presentation, SAVS were most highly concentrated in the cervical region (40.6%). Children had a median AL=2 and MC=2, with thoracolumbar AVS carrying the greatest disability. Among treated cases, complete obliteration was achieved in 48% of cases and median AL scores and MC grades both improved by one point. Systematic literature review identified 161 children (M:F=96:65) with 166 SAVS lesions with a mean age of 8.7±0.4 years. Among studies describing symptom chronicity, 37/51 (72.5%) of children presented acutely. At presentation, children had a median AL=4 and MC=3, with thoracolumbar AVS carrying the highest MC grades. After intervention, median AL and MC both improved by one point. CONCLUSIONS: This study provides epidemiologic information on the location, onset, and presentation of the full spectrum of pediatric SAVS, highlighting the role of targeted treatment of high-risk features.


Asunto(s)
Embolización Terapéutica , Médula Espinal , Humanos , Niño , Adolescente , Estudios Retrospectivos , Estudios de Cohortes , Cuello , Resultado del Tratamiento
10.
J Neurointerv Surg ; 2023 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-37468266

RESUMEN

BACKGROUND: Neurointerventional robotic systems have potential to reduce occupational radiation, improve procedural precision, and allow for future remote teleoperation. A limited number of single institution case reports and series have been published outlining the safety and feasibility of robot-assisted diagnostic cerebral angiography. METHODS: This is a multicenter, retrospective case series of patients undergoing diagnostic cerebral angiography at three separate institutions - University of California, Davis (UCD); University of California, Los Angeles (UCLA); and University of California, San Francisco (UCSF). The equipment used was the CorPath GRX Robotic System (Corindus, Waltham, MA). RESULTS: A total of 113 cases were analyzed who underwent robot-assisted diagnostic cerebral angiography from September 28, 2020 to October 27, 2022. There were no significant complications related to use of the robotic system including stroke, arterial dissection, bleeding, or pseudoaneurysm formation at the access site. Using the robotic system, 88 of 113 (77.9%) cases were completed successfully without unplanned manual conversion. The principal causes for unplanned manual conversion included challenging anatomy, technical difficulty with the bedside robotic cassette, and hubbing out of the robotic system due to limited working length. For robotic operation, average fluoroscopy time was 13.2 min (interquartile range (IQR), 9.3 to 16.8 min) and average cumulative air kerma was 975.8 mGY (IQR, 350.8 to 1073.5 mGy). CONCLUSIONS: Robotic cerebral angiography with the CorPath GRX Robotic System is safe and easily learned by novice users without much prior manual experience. However, there are technical limitations such as a short working length and an inability to support 0.035" wires which may limit its widespread adoption in clinical practice.

11.
World Neurosurg ; 164: e509-e517, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35552027

RESUMEN

BACKGROUND: Methamphetamine (MA) use is associated with poor outcomes after aneurysmal subarachnoid hemorrhage (aSAH). MA exerts both hemodynamic and inflammatory effects, but whether these manifest with altered intracranial aneurysm (IA) remodeling is unknown. The objective of this study was to compare IA geometric and morphologic features in patients with and without MA detected on urine toxicology (Utox) at presentation. METHODS: We retrospectively reviewed 160 consecutive patients with SAH and Utox at time of admission. Geometric-morphologic IA characteristics were assessed by blinded neuroradiologists. Studied features were maximum sac diameter, location, size, ellipsoid volume, aspect ratio, size ratio, volume: neck ratio, dome: neck ratio, bottleneck factor, morphology (saccular, fusiform/dissecting, blister, mycotic), and presence of bleb, vasculopathy, or additional unruptured IA. RESULTS: Of 139/160 patients with aSAH, 23/139 (16.5%) were Utox MA+. There was no difference in aneurysm subtype frequency, presence of bleb, vasculopathy, or presence of an additional (unruptured) aneurysm with a trend toward posterior circulation location and higher Hunt and Hess grade (P = 0.09 for both) in the MA+ group. Maximum IA sac diameter, ellipsoid volume, dome-neck ratio, and size ratio were similar between groups. Only the aspect ratio (AR) differed between groups (MA+ = 2.20 vs. MA- = 1.74, P = 0.02). The AR remained a significant predictor of Utox MA+ in a multiple logistic regression analysis (odds ratio 1.87, 95% confidence interval 1.06-3.39). CONCLUSIONS: Active use of methamphetamine is independently associated with larger AR in patients with ruptured IA. This may indicate hazardous remodeling due to hemodynamic and/or inflammatory changes.


Asunto(s)
Aneurisma Roto , Aneurisma Intracraneal , Metanfetamina , Hemorragia Subaracnoidea , Humanos , Aneurisma Roto/complicaciones , Aneurisma Roto/diagnóstico por imagen , Aneurisma Intracraneal/complicaciones , Aneurisma Intracraneal/diagnóstico por imagen , Metanfetamina/efectos adversos , Estudios Retrospectivos , Hemorragia Subaracnoidea/complicaciones , Hemorragia Subaracnoidea/diagnóstico por imagen
12.
Clin Neurol Neurosurg ; 213: 107122, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35033791

RESUMEN

OBJECTIVE: Stent retriever (SR) and direct aspiration (DA) mechanical thrombectomy (MT) improve clinical outcomes for stroke secondary to large vessel occlusion. The purpose is to perform an updated meta-analysis comparing the two techniques. METHODS: PubMed database was searched for studies between January 1, 2015, and July 5th, 2021 with mechanical thrombectomy to treat acute ischemic stroke. RESULTS: We identified 136 studies including 17,556 patients, with 11,258 (64.1%) patients treated by SR or a combined approach and 6298 (35.9%) patients with DA. The DA group had less posterior cerebral artery strokes, was significantly older, and had lower National Institutes of Health Stroke Scale scores (p = .05,.02,.04) There was no difference between groups in percentage of middle cerebral artery or internal carotid artery occlusions or intravenous tissue plasminogen activator administered (p = .62,.19,.06). A regression model showed no difference between SR and DA in mortality, symptomatic intracranial hemorrhage, and disability (mRS > 2) at 90 days (p = .13,.75,.84). Successful reperfusion (mTICI 2b/3 rates) were higher in the DA group (DA 87.6% vs SR 82.3%, p < .01), but after accounting for covariates was not significant (p = .17). CONCLUSION: Our updated meta-analysis shows that DA has similar safety, reperfusion and 90-day clinical outcomes compared to SR. These results should serve to increase confidence in DA thrombectomy for acute ischemic stroke secondary to LVO.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Isquemia Encefálica/complicaciones , Humanos , Estudios Retrospectivos , Stents/efectos adversos , Accidente Cerebrovascular/complicaciones , Trombectomía/métodos , Activador de Tejido Plasminógeno , Resultado del Tratamiento
13.
BMC Struct Biol ; 11: 39, 2011 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-21995815

RESUMEN

BACKGROUND: Ribose-5-phosphate isomerase is an enzyme that catalyzes the interconversion of ribose-5-phosphate and ribulose-5-phosphate. This family of enzymes naturally occurs in two distinct classes, RpiA and RpiB, which play an important role in the pentose phosphate pathway and nucleotide and co-factor biogenesis. RESULTS: Although RpiB occurs predominantly in bacteria, here we report crystal structures of a putative RpiB from the pathogenic fungus Coccidioides immitis. A 1.9 Å resolution apo structure was solved by combined molecular replacement and single wavelength anomalous dispersion (SAD) phasing using a crystal soaked briefly in a solution containing a high concentration of iodide ions. RpiB from C. immitis contains modest sequence and high structural homology to other known RpiB structures. A 1.8 Å resolution phosphate-bound structure demonstrates phosphate recognition and charge stabilization by a single positively charged residue whereas other members of this family use up to five positively charged residues to contact the phosphate of ribose-5-phosphate. A 1.7 Å resolution structure was obtained in which the catalytic base of C. immitis RpiB, Cys76, appears to form a weakly covalent bond with the central carbon of malonic acid with a bond distance of 2.2 Å. This interaction may mimic that formed by the suicide inhibitor iodoacetic acid with RpiB. CONCLUSION: The C. immitis RpiB contains the same fold and similar features as other members of this class of enzymes such as a highly reactive active site cysteine residue, but utilizes a divergent phosphate recognition strategy and may recognize a different substrate altogether.


Asunto(s)
Isomerasas Aldosa-Cetosa/química , Coccidioides/enzimología , Isomerasas Aldosa-Cetosa/genética , Isomerasas Aldosa-Cetosa/metabolismo , Secuencia de Aminoácidos , Sitios de Unión , Dominio Catalítico , Cristalografía por Rayos X , Yoduros/química , Datos de Secuencia Molecular , Estructura Terciaria de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Ribulosafosfatos/química , Ribulosafosfatos/metabolismo , Alineación de Secuencia , Especificidad por Sustrato
14.
Artículo en Inglés | MEDLINE | ID: mdl-21904052

RESUMEN

Babesiosis is a tick-borne disease caused by eukaryotic Babesia parasites which are morphologically similar to Plasmodium falciparum, the causative agent of malaria in humans. Like Plasmodium, different species of Babesia are tuned to infect different mammalian hosts, including rats, dogs, horses and cattle. Most species of Plasmodium and Babesia possess an essential bifunctional enzyme for nucleotide synthesis and folate metabolism: dihydrofolate reductase-thymidylate synthase. Although thymidylate synthase is highly conserved across organisms, the bifunctional form of this enzyme is relatively uncommon in nature. The structural characterization of dihydrofolate reductase-thymidylate synthase in Babesia bovis, the causative agent of babesiosis in livestock cattle, is reported here. The apo state is compared with structures that contain dUMP, NADP and two different antifolate inhibitors: pemetrexed and raltitrexed. The complexes reveal modes of binding similar to that seen in drug-resistant malaria strains and point to the utility of applying structural studies with proven cancer chemotherapies towards infectious disease research.


Asunto(s)
Babesia bovis/enzimología , Inhibidores Enzimáticos/química , Complejos Multienzimáticos/química , Tetrahidrofolato Deshidrogenasa/química , Timidilato Sintasa/química , Apoproteínas/química , Apoproteínas/metabolismo , Cristalografía por Rayos X , Inhibidores Enzimáticos/metabolismo , Ligandos , Modelos Moleculares , Complejos Multienzimáticos/metabolismo , Unión Proteica , Estructura Cuaternaria de Proteína , Estructura Terciaria de Proteína , Homología Estructural de Proteína , Especificidad por Sustrato , Tetrahidrofolato Deshidrogenasa/metabolismo , Timidilato Sintasa/metabolismo
15.
Acta Crystallogr Sect F Struct Biol Cryst Commun ; 67(Pt 9): 1015-21, 2011 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-21904043

RESUMEN

The Protein Maker is an automated purification system developed by Emerald BioSystems for high-throughput parallel purification of proteins and antibodies. This instrument allows multiple load, wash and elution buffers to be used in parallel along independent lines for up to 24 individual samples. To demonstrate its utility, its use in the purification of five recombinant PB2 C-terminal domains from various subtypes of the influenza A virus is described. Three of these constructs crystallized and one diffracted X-rays to sufficient resolution for structure determination and deposition in the Protein Data Bank. Methods for screening lysis buffers for a cytochrome P450 from a pathogenic fungus prior to upscaling expression and purification are also described. The Protein Maker has become a valuable asset within the Seattle Structural Genomics Center for Infectious Disease (SSGCID) and hence is a potentially valuable tool for a variety of high-throughput protein-purification applications.


Asunto(s)
Automatización/instrumentación , Coccidioides/química , Esterol 14-Desmetilasa/aislamiento & purificación , Automatización/métodos , Coccidioides/enzimología , Esterol 14-Desmetilasa/metabolismo
16.
J Phys Chem A ; 115(16): 4101-13, 2011 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-21417384

RESUMEN

The pump-probe polarization anisotropy is computed for molecules with a nondegenerate ground state, two degenerate or nearly degenerate excited states with perpendicular transition dipoles, and no resonant excited-state absorption. Including finite pulse effects, the initial polarization anisotropy at zero pump-probe delay is predicted to be r(0) = 3/10 with coherent excitation. During pulse overlap, it is shown that the four-wave mixing classification of signal pathways as ground or excited state is not useful for pump-probe signals. Therefore, a reclassification useful for pump-probe experiments is proposed, and the coherent anisotropy is discussed in terms of a more general transition dipole and molecular axis alignment instead of experiment-dependent ground- versus excited-state pathways. Although coherent excitation enhances alignment of the transition dipole, the molecular axes are less aligned than for a single dipole transition, lowering the initial anisotropy. As the splitting between excited states increases beyond the laser bandwidth and absorption line width, the initial anisotropy increases from 3/10 to 4/10. Asymmetric vibrational coordinates that lift the degeneracy control the electronic energy gap and off-diagonal coupling between electronic states. These vibrations dephase coherence and equilibrate the populations of the (nearly) degenerate states, causing the anisotropy to decay (possibly with oscillations) to 1/10. Small amounts of asymmetric inhomogeneity (2 cm(-1)) cause rapid (130 fs) suppression of both vibrational and electronic anisotropy beats on the excited state, but not vibrational beats on the ground electronic state. Recent measurements of conical intersection dynamics in a silicon napthalocyanine revealed anisotropic quantum beats that had to be assigned to asymmetric vibrations on the ground electronic state only [Farrow, D. A.; J. Chem. Phys. 2008, 128, 144510]. Small environmental asymmetries likely explain the observed absence of excited-state asymmetric vibrations in those experiments.


Asunto(s)
Teoría Cuántica , Anisotropía , Vibración
17.
Public Underst Sci ; 19(5): 514-27, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21553598

RESUMEN

Our study examines how individuals decide which scientific claims and experts to believe when faced with competing claims regarding a policy issue. Using an experiment in a public opinion survey, we test the source content and credibility hypotheses to assess how much confidence people have in reports about scientific studies of the safety of offshore oil drilling along the California coast. The results show that message content has a substantial impact. People tend to accept reports of scientific studies that support their values and prior beliefs, but not studies that contradict them. Previous studies have shown that core values influence message acceptance. We find that core values and prior beliefs have independent effects on message acceptance. We also find that the sources of the claims make little difference. Finally, the public leans toward believing reports that oil drilling is riskier than previously believed.


Asunto(s)
Comunicación , Industria Procesadora y de Extracción , Opinión Pública , California , Comprensión , Política Ambiental , Humanos , Océano Pacífico , Petróleo , Confianza
18.
Urol Pract ; 7(6): 474-480, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37287182

RESUMEN

INTRODUCTION: As patients increasingly use physician review websites as their primary source for finding new doctors, urologists must adapt and control their online presence. Herein, we identify factors that impact physician review website ratings, address opportunities to improve online presence and investigate the validity of online physician ratings by comparing their scores to quality measures. METHODS: We extracted urologist profiles from Healthgrades.com (9,902) and Vitals.com (11,670), the 2 largest physician review website platforms, using an automated web scraper. The provider profiles included demographics, rating information, patient survey data and other information provided by the physician. We also obtained rates of surgical complications, Medicare billing practices and prescribing history from public online databases and other demographic data from the 2010 U.S. Census Bureau, which was cross analyzed with physician review website data using proportional odds logistic regression. RESULTS: Ratings among urologist profiles on Healthgrades.com and Vitals.com were similar and had a correlation coefficient of 0.34 (p <0.001). We noted wait time as the most consistent theme that negatively impacted the physician ratings. For those in the group with the highest number of scores, merely correcting a profile and adding a picture was beneficial. As providers accumulated higher numbers of ratings their scores generally became increasingly positive with less variance. We did not find that physician review website ratings correlate with outcome measures. CONCLUSIONS: Urologist profiles on physician review website platforms are strongly associated with the number of reviews and wait times. Targeting these areas could improve their online presence. However online reviews do not correspond to surgical quality.

19.
J Phys Chem A ; 113(47): 13287-99, 2009 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-19780599

RESUMEN

Four-level two-dimensional (2D) Fourier transform relaxation spectra are simulated with response functions for a chromophore pair in the exponential relaxation (optical Bloch model) limit. The parameters in this study are chosen to model coupled carbonyl stretching vibrations. As long as coherence persists, every peak in the real 2D spectra has a partially mixed absorptive/dispersive ("phase-twisted") shape because the nonlinear signals are not symmetric with respect to interchange of the first two pulses. This asymmetry in 2D relaxation spectra arises from coherence between singly excited states and a red shift of the doubly excited state. Coherence between the singly excited states causes oscillation of the 2D spectra and the associated spectrally resolved pump-probe (SRPP) transients at the quantum beat frequency. Projecting the phase-twisted nature of the 2D peaks onto the detection frequency axis, the SRPP peaks are also asymmetric about their maximum when not at maximum or minimum amplitude. Three-dimensional Fourier transform (3DFT) methods are used to simulate absorption/dispersion and beam geometry distortions of the multilevel 2D spectra with cross peaks. The distortions can be understood by consideration of their effects on individual coherence pathways that contribute to peaks in the 2D spectra. The beam geometry distortion explains some unequal cross peak amplitudes previously observed experimentally by Khalil et al. (J. Chem. Phys. 2004, 121, 362). A representation of 2D spectra that reduces beam geometry distortion is presented. If the transformation to correct for beam geometry distortion is combined with the transformations that correct absorptive/dispersive propagation distortions (J. Chem. Phys. 2007, 126, 044511), the recovered 2D spectrum matches the ideal 2D spectrum after all coherence is destroyed. In the presence of coherence, the new representation reduces the error in the distorted 2D spectrum by a factor of 4 for practical 2D-IR experimental conditions.

20.
Otolaryngol Head Neck Surg ; 161(1): 28-35, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30909841

RESUMEN

OBJECTIVE: Tinnitus is a condition that causes distress and impairment across cognitive, functional, and psychiatric spectra. In the psychiatric realm, tinnitus has long been associated with depression. To better characterize the co-occurrence of depression and tinnitus, we performed a systematic review of the prevalence of depression among patients with tinnitus. DATA SOURCES: We comprehensively examined original studies reporting the prevalence of depression in adult populations with tinnitus, as indexed in the PubMed and Web of Science databases and published from January 2006 to August 2016. REVIEW METHODS: All identified articles were reviewed independently by 2 researchers, with a third reviewer for adjudication. Included studies were evaluated for threats to validity across 3 domains-representativeness, response rate, and ascertainment of outcome-on a 4-point modified Newcastle-Ottawa Quality Assessment Scale. RESULTS: Twenty-eight studies were included, representing 15 countries and 9979 patients with tinnitus. Among the included studies, the median prevalence of depression was 33%, with an interquartile range of 19% to 49% and an overall range of 6% to 84%. Studies were high quality overall, with a mean score of 3.3 (SD = 0.76), and 89% utilized a validated tool to ascertain depression. CONCLUSIONS: We conducted one of the largest contemporary comprehensive reviews, which suggests a 33% prevalence of depression among patients with tinnitus. Our review reaffirms that a substantial proportion of patients with tinnitus have depression, and we recommend that all who treat tinnitus should screen and treat their patients for depression, if present.


Asunto(s)
Depresión/epidemiología , Depresión/psicología , Acúfeno/psicología , Humanos , Prevalencia
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