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3.
Artículo en Inglés | MEDLINE | ID: mdl-38797882

RESUMEN

BACKGROUND: Despite the high incidence of blunt trauma in older adults, there is a lack of evidence-based guidance for computed tomography (CT) imaging in this population. We aimed to identify an algorithm to guide use of a Pan-Scan (Head/C-spine/Torso) or a Selective Scan (Head/C-spine ± Torso). We hypothesized that a patient's initial history and exam could be used to guide imaging. METHODS: We prospectively studied blunt trauma patients aged 65+ at 18 Level I/II trauma centers. Patients presenting >24 h after injury or who died upon arrival were excluded. We collected history and physical elements and final injury diagnoses. Injury diagnoses were categorized into CT body regions of Head/C-spine or Torso (chest, abdomen/pelvis, and T/L spine). Using machine learning and regression modeling as well as a priori clinical algorithms based, we tested various decision rules against our dataset. Our priority was to identify a simple rule which could be applied at the bedside, maximizing sensitivity (Sens) and negative predictive value (NPV) to minimize missed injuries. RESULTS: We enrolled 5,498 patients with 3,082 injuries. Nearly half (47.1%, n = 2,587) had an injury within the defined CT body regions. No rule to guide a Pan-Scan could be identified with suitable Sens/NPV for clinical use. A clinical algorithm to identify patients for Pan-Scan, using a combination of physical exam findings and specific high-risk criteria, was identified and had a Sens of 0.94 and NPV of 0.86 This rule would have identified injuries in all but 90 patients (1.6%) and would theoretically spare 11.9% (655) of blunt trauma patients a torso CT. CONCLUSIONS: Our findings advocate for Head/Cspine CT in all geriatric patients with the addition of torso CT in the setting of positive clinical findings and high-risk criteria. Prospective validation of this rule could lead to streamlined diagnostic care of this growing trauma population. LEVEL OF EVIDENCE: Level 2, Diagnostic Tests or Criteria.

4.
Heart Lung Circ ; 33(6): 764-772, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38565438

RESUMEN

The percutaneous management of chronic total occlusions (CTO) is a well-established sub-specialty of Interventional Cardiology, requiring specialist equipment, training, and techniques. The heterogeneity of approaches in CTO has led to the generation of multiple algorithms to guide operators in their management. The evidence base for management of CTOs has suffered from inconsistent descriptive and quantitative terminology in defining the nature of lesions and techniques utilised, as well as seemingly contradictory data about improvement in ventricular function, symptoms of angina, and mortality from large-scale registries and randomised controlled trials. Through this review, we explore the history of CTO management and its supporting evidence in detail, with an outline of limitations of CTO-percutaneous coronary intervention and a look at the future of this growing field within cardiology.


Asunto(s)
Oclusión Coronaria , Intervención Coronaria Percutánea , Humanos , Oclusión Coronaria/diagnóstico , Oclusión Coronaria/terapia , Oclusión Coronaria/cirugía , Intervención Coronaria Percutánea/métodos , Enfermedad Crónica
5.
Matrix Biol ; 129: 44-58, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38582404

RESUMEN

Extracellular matrix (ECM) pathologic remodeling underlies many disorders, including muscular dystrophy. Tissue decellularization removes cellular components while leaving behind ECM components. We generated "on-slide" decellularized tissue slices from genetically distinct dystrophic mouse models. The ECM of dystrophin- and sarcoglycan-deficient muscles had marked thrombospondin 4 deposition, while dysferlin-deficient muscle had excess decorin. Annexins A2 and A6 were present on all dystrophic decellularized ECMs, but annexin matrix deposition was excessive in dysferlin-deficient muscular dystrophy. Muscle-directed viral expression of annexin A6 resulted in annexin A6 in the ECM. C2C12 myoblasts seeded onto decellularized matrices displayed differential myoblast mobility and fusion. Dystrophin-deficient decellularized matrices inhibited myoblast mobility, while dysferlin-deficient decellularized matrices enhanced myoblast movement and differentiation. Myoblasts treated with recombinant annexin A6 increased mobility and fusion like that seen on dysferlin-deficient decellularized matrix and demonstrated upregulation of ECM and muscle cell differentiation genes. These findings demonstrate specific fibrotic signatures elicit effects on myoblast activity.


Asunto(s)
Diferenciación Celular , Movimiento Celular , Disferlina , Matriz Extracelular , Mioblastos , Sarcoglicanos , Animales , Mioblastos/metabolismo , Mioblastos/citología , Matriz Extracelular/metabolismo , Ratones , Sarcoglicanos/genética , Sarcoglicanos/metabolismo , Disferlina/genética , Disferlina/metabolismo , Distrofias Musculares/genética , Distrofias Musculares/metabolismo , Distrofias Musculares/patología , Distrofina/genética , Distrofina/metabolismo , Anexina A2/genética , Anexina A2/metabolismo , Decorina/genética , Decorina/metabolismo , Línea Celular , Modelos Animales de Enfermedad , Músculo Esquelético/metabolismo
6.
J Neurosurg ; : 1-9, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38518289

RESUMEN

OBJECTIVE: The influence of socioeconomic factors on racial disparities among patients with sporadic meningiomas is well established, yet other potential causative factors warrant further exploration. The authors of this study aimed to determine whether there is significant variation in the genomic profile of meningiomas among patients of different races and ethnicities and its correlation with clinical outcomes. METHODS: The demographic, genomic, and clinical data of patients aged 18 years and older who had undergone surgery for sporadic meningioma between September 2008 and November 2021 were analyzed. Statistical analyses were performed to detect differences across all racial/ethnic groups, as were direct comparisons between Black and non-Black groups plus Hispanic and non-Hispanic groups. RESULTS: This study included 460 patients with intracranial meningioma. Hispanic patients were significantly younger at surgery (53.9 vs 60.2 years, p = 0.0006) and more likely to show symptoms. Black patients had a higher incidence of anterior skull base tumors (OR 3.2, 95% CI 1.7-6.3, p = 0.0008) and somatic hedgehog mutations (OR 5.3, 95% CI 1.6-16.6, p = 0.003). Hispanics were less likely to exhibit the aggressive genomic characteristic of chromosome 1p deletion (OR 0.28, 95% CI 0.07-1.2, p = 0.06) and displayed higher rates of TRAF7 somatic driver mutations (OR 2.96 95% CI 1.1-7.8, p = 0.036). Black patients had higher rates of recurrence (OR 2.6, 95% CI 1.3-5.2, p = 0.009) and shorter progression-free survival (PFS; HR 2.9, 95% CI 1.6-5.4, p = 0.002) despite extents of resection (EORs) similar to those of non-Black patients (p = 0.745). No significant differences in overall survival were observed among groups. CONCLUSIONS: Despite similar EORs, Black patients had worse clinical outcomes following meningioma resection, characterized by a higher prevalence of somatic hedgehog mutations, increased recurrence rates, and shorter PFS. Meanwhile, Hispanic patients had less aggressive meningiomas, a predisposition for TRAF7 mutations, and no difference in PFS. These findings could inform the care and treatment strategies for meningiomas, and they establish the foundation for future studies focusing on the genomic origins of these observed differences.

7.
Am J Cardiol ; 219: 25-34, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38447892

RESUMEN

Metabolic syndrome (MetS) provides significant risk for coronary disease, however long-term prognosis after percutaneous coronary intervention (PCI) has been understudied. We assessed the prevalence and outcomes of patients with MetS from an Australian PCI cohort. We retrospectively examined data from the Melbourne Interventional Group multicenter PCI registry using a modified definition for MetS including ≥3 of the following: hypertension, diabetes mellitus, dyslipidemia, and body mass index ≥30 kg/m2. Thirty-day outcomes and long-term mortality were compared with patients without MetS. Cox regression methods were used to assess the multivariable effect of MetS on long-term mortality. Of 41,146 patients, 12,228 (34%) had MetS. Patients with MetS experienced greater 30-day myocardial infarction (2.2% vs 1.8%, p = 0.013), whereas patients without MetS had a trend for greater 30-day mortality (3.0% vs 3.4%, p = 0.051) and greater in-hospital major bleeding (1.7% vs 2.4%, p <0.001). After a median follow-up of 5.62 years (Q1 2.03, Q3 8.89), patients with MetS experienced greater mortality (24% vs 19%, p <0.001). After adjustment, MetS was not an independent predictor of long-term mortality (hazard ratio 0.95 confidence interval 0.86 to 1.05, p = 0.35). In sensitivity analyses, MetS-Diabetic patients had the highest, and MetS-NonDiabetic obese patients had the lowest long-term mortality. One in 3 patients who underwent all-comer PCI presented with MetS and experienced greater long-term mortality compared with others. However, this association was lost after adjustment for baseline confounders, highlighting that MetS is a marker of risk after PCI. Our findings support the obesity paradox and confirm robust associations between diabetes mellitus and long-term mortality.


Asunto(s)
Síndrome Metabólico , Intervención Coronaria Percutánea , Humanos , Síndrome Metabólico/complicaciones , Síndrome Metabólico/epidemiología , Masculino , Femenino , Persona de Mediana Edad , Australia/epidemiología , Estudios Retrospectivos , Anciano , Factores de Riesgo , Sistema de Registros , Enfermedad de la Arteria Coronaria/mortalidad , Enfermedad de la Arteria Coronaria/cirugía , Enfermedad de la Arteria Coronaria/complicaciones , Prevalencia , Pronóstico , Estudios de Seguimiento , Tasa de Supervivencia/tendencias , Factores de Tiempo
8.
JCI Insight ; 9(3)2024 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-38175727

RESUMEN

The Murphy Roths Large (MRL) mouse strain has "super-healing" properties that enhance recovery from injury. In mice, the DBA/2J strain intensifies many aspects of muscular dystrophy, so we evaluated the ability of the MRL strain to suppress muscular dystrophy in the Sgcg-null mouse model of limb girdle muscular dystrophy. A comparative analysis of Sgcg-null mice in the DBA/2J versus MRL strains showed greater myofiber regeneration, with reduced structural degradation of muscle in the MRL strain. Transcriptomic profiling of dystrophic muscle indicated strain-dependent expression of extracellular matrix (ECM) and TGF-ß signaling genes. To investigate the MRL ECM, cellular components were removed from dystrophic muscle sections to generate decellularized myoscaffolds. Decellularized myoscaffolds from dystrophic mice in the protective MRL strain had significantly less deposition of collagen and matrix-bound TGF-ß1 and TGF-ß3 throughout the matrix. Dystrophic myoscaffolds from the MRL background, but not the DBA/2J background, were enriched in myokines like IGF-1 and IL-6. C2C12 myoblasts seeded onto decellularized matrices from Sgcg-/- MRL and Sgcg-/- DBA/2J muscles showed the MRL background induced greater myoblast differentiation compared with dystrophic DBA/2J myoscaffolds. Thus, the MRL background imparts its effect through a highly regenerative ECM, which is active even in muscular dystrophy.


Asunto(s)
Distrofia Muscular de Cinturas , Distrofias Musculares , Ratones , Animales , Ratones Endogámicos DBA , Distrofias Musculares/genética , Músculos , Matriz Extracelular , Ratones Noqueados
9.
J Neurooncol ; 164(2): 299-308, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37624530

RESUMEN

PURPOSE: Frailty has gained prominence in neurosurgical oncology, with more studies exploring its relationship to postoperative outcomes in brain tumor patients. As this body of literature continues to grow, concisely reviewing recent developments in the field is necessary. Here we provide a systematic review of frailty in brain tumor patients subdivided by tumor type, incorporating both modern frailty indices and traditional Karnofsky Performance Status (KPS) metrics. METHODS: Systematic literature review was performed using PRISMA guidelines. PubMed and Google Scholar were queried for articles related to frailty, KPS, and brain tumor outcomes. Only articles describing novel associations between frailty or KPS and primary intracranial tumors were included. RESULTS: After exclusion criteria, systematic review yielded 52 publications. Amongst malignant lesions, 16 studies focused on glioblastoma. Amongst benign tumors, 13 focused on meningiomas, and 6 focused on vestibular schwannomas. Seventeen studies grouped all brain tumor patients together. Seven studies incorporated both frailty indices and KPS into their analyses. Studies correlated frailty with various postoperative outcomes, including complications and mortality. CONCLUSION: Our review identified several patterns of overall postsurgical outcomes reporting for patients with brain tumors and frailty. To date, reviews of frailty in patients with brain tumors have been largely limited to certain frailty indices, analyzing all patients together regardless of lesion etiology. Although this technique is beneficial in providing a general overview of frailty's use for brain tumor patients, given each tumor pathology has its own unique etiology, this combined approach potentially neglects key nuances governing frailty's use and prognostic value.


Asunto(s)
Neoplasias Encefálicas , Fragilidad , Neoplasias Meníngeas , Humanos , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/cirugía , Fragilidad/complicaciones , Neoplasias Meníngeas/cirugía , Complicaciones Posoperatorias/etiología , Pronóstico , Resultado del Tratamiento
10.
bioRxiv ; 2023 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-37425960

RESUMEN

Genetic background shifts the severity of muscular dystrophy. In mice, the DBA/2J strain confers a more severe muscular dystrophy phenotype, whereas the Murphy's Roth Large (MRL) strain has "super-healing" properties that reduce fibrosis. A comparative analysis of the Sgcg null model of Limb Girdle Muscular Dystrophy in the DBA/2J versus MRL strain showed the MRL background was associated with greater myofiber regeneration and reduced structural degradation of muscle. Transcriptomic profiling of dystrophic muscle in the DBA/2J and MRL strains indicated strain-dependent expression of the extracellular matrix (ECM) and TGF-ß signaling genes. To investigate the MRL ECM, cellular components were removed from dystrophic muscle sections to generate decellularized "myoscaffolds". Decellularized myoscaffolds from dystrophic mice in the protective MRL strain had significantly less deposition of collagen and matrix-bound TGF-ß1 and TGF-ß3 throughout the matrix, and dystrophic myoscaffolds from the MRL background were enriched in myokines. C2C12 myoblasts were seeded onto decellularized matrices from Sgcg-/- MRL and Sgcg-/- DBA/2J matrices. Acellular myoscaffolds from the dystrophic MRL background induced myoblast differentiation and growth compared to dystrophic myoscaffolds from the DBA/2J matrices. These studies establish that the MRL background also generates its effect through a highly regenerative ECM, which is active even in muscular dystrophy.

11.
J Neurooncol ; 163(3): 529-539, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37440095

RESUMEN

PURPOSE: Social determinants of health broadly affect healthcare access and outcomes. Studies report that minorities and low socioeconomic status (SES) patients undergoing intracranial meningioma resection demonstrate worse outcomes and higher mortality rates. This systematic review and meta-analysis summarizes the available research reporting racial and SES disparities in intracranial meningioma resection outcomes. METHODS: A systematic review was conducted using PRISMA guidelines and included peer-reviewed, English-language articles from the United States between 2000 and 2022 that reported racial and SES disparities in meningioma outcomes. Outcomes included overall survival (OS), extent of resection (EOR), hospitalization costs, length of stay (LOS), 30-day readmission, recurrence, and receipt of surgery and adjuvant radiotherapy. A quantitative meta-analysis was performed only on survival outcomes by race. All other variables were summarized as a systematic review. RESULTS: 633 articles were identified; 19 studies met inclusion criteria. Black or low SES patients were more likely to have increased hospitalization costs, rates of 30-day readmission, LOS, recurrence and less likely to undergo surgery, gross total resection, and adjuvant radiotherapy for their tumors. Six studies were used for the quantitative meta-analysis of race and OS. Compared to White patients, Black patients had significantly worse survival outcomes, and Asian patients had significantly better survival outcomes. CONCLUSION: Disparities in outcomes exist for patients who undergo surgery for meningioma, such that Black and low SES patients have worse outcomes. The literature is quite sparse and contains confounding relationships not often accounted for appropriately. Further studies are needed to help understand these disparities to improve outcomes.


Asunto(s)
Neoplasias Meníngeas , Meningioma , Humanos , Estados Unidos , Meningioma/patología , Clase Social , Hospitalización , Tiempo de Internación , Neoplasias Meníngeas/patología , Disparidades en Atención de Salud
12.
Surg Infect (Larchmt) ; 24(6): 514-521, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37327050

RESUMEN

Abstract Background: Anterior lumbar interbody fusion (ALIF) has become an increasingly popular and effective treatment modality for various conditions of the lumbar spine. However, complications after this procedure can be costly. Surgical site infections (SSIs) are one of these types of complications. The present study identifies independent risk factors for SSI after single-level ALIF to identify high-risk patients better. Patients and Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried to identify single-level ALIF patients from 2005 to 2016. Multilevel fusions and non-anterior approach procedures were excluded. Mann-Pearson χ2 tests analyzed categorical variables, whereas one-way analysis of variance (ANOVA) and independent t-tests analyzed differences in mean values of continuous variables. Risk factors for SSI were identified via a multivariable logistic regression model. A receiver operating characteristic (ROC) curve was generated utilizing the predicted probabilities. Results: A total of 10,017 patients met inclusion criteria; 80 (0.80%) had developed SSI and 9,937 (99.20%) had not. On multivariable logistic regression models, class 3 obesity (p = 0.014), dialysis (p = 0.025), long-term steroid use (p = 0.010), and wound classification 4 (dirty/infected) (p = 0.002) all independently increased the risk for SSI in single-level ALIF. The area under the receiver operating characteristic curve (AUROC; C-statistic) was 0.728 (p < 0.001), indicating relatively strong reliability of the final model. Conclusions: Several independent risk factors including obesity, dialysis, long-term steroid use, and dirty wound classification all increased risk for SSI after single-level ALIF. By identifying these high-risk patients, surgeons and patients can have more informed pre-operative discussions. In addition, identifying and optimizing these patients prior to operative intervention may help to minimize infection risk.


Asunto(s)
Fusión Vertebral , Infección de la Herida Quirúrgica , Humanos , Infección de la Herida Quirúrgica/etiología , Reproducibilidad de los Resultados , Factores de Riesgo , Obesidad/complicaciones , Vértebras Lumbares/cirugía , Fusión Vertebral/efectos adversos , Fusión Vertebral/métodos , Esteroides , Estudios Retrospectivos , Complicaciones Posoperatorias/etiología
13.
J Neurosurg ; 139(6): 1648-1656, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-37243548

RESUMEN

OBJECTIVE: Mutations in NF2 are the most common somatic driver mutation in sporadic meningiomas. NF2 mutant meningiomas preferentially arise along the cerebral convexities-however, they can also be found in the posterior fossa. The authors investigated whether NF2 mutant meningiomas differ in clinical and genomic features based on their location relative to the tentorium. METHODS: Clinical and whole exome sequencing (WES) data for patients who underwent resection of sporadic NF2 mutant meningiomas were reviewed and analyzed. RESULTS: A total of 191 NF2 mutant meningiomas were included (165 supratentorial, 26 infratentorial). Supratentorial NF2 mutant meningiomas were significantly associated with edema (64.0% vs 28.0%, p < 0.001); higher grade-i.e., WHO grade II or III (41.8% vs 3.9%, p < 0.001); elevated Ki-67 (55.0% vs 13.6%, p < 0.001); and larger volume (mean 45.5 cm3 vs 14.9 cm3, p < 0.001). Furthermore, supratentorial tumors were more likely to harbor the higher-risk feature of chromosome 1p deletion (p = 0.038) and had a larger fraction of the genome altered with loss of heterozygosity (p < 0.001). Infratentorial meningiomas were more likely to undergo subtotal resection than supratentorial tumors (37.5% vs 15.8%, p = 0.021); however, there was no significant difference in overall (p = 0.2) or progression-free (p = 0.4) survival. CONCLUSIONS: Supratentorial NF2 mutant meningiomas are associated with more aggressive clinical and genomic features as compared with their infratentorial counterparts. Although infratentorial tumors have higher rates of subtotal resection, there is no associated difference in survival or recurrence. These findings help to better inform surgical decision-making in the management of NF2 mutant meningiomas based on location, and may guide postoperative management of these tumors.


Asunto(s)
Neoplasias Meníngeas , Meningioma , Neoplasias Supratentoriales , Humanos , Meningioma/genética , Meningioma/cirugía , Meningioma/complicaciones , Neoplasias Meníngeas/genética , Neoplasias Meníngeas/cirugía , Neoplasias Meníngeas/complicaciones , Mutación/genética , Genómica , Neoplasias Supratentoriales/genética , Neoplasias Supratentoriales/cirugía
14.
J Neurooncol ; 162(2): 253-265, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37010677

RESUMEN

INTRODUCTION: Surgical resection has long been the treatment of choice for meningiomas and is considered curative in many cases. Indeed, the extent of resection (EOR) remains a significant factor in determining disease recurrence and outcome optimization for patients undergoing surgery. Although the Simpson Grading Scale continues to be widely accepted as the measure of EOR and is used to predict symptomatic recurrence, its utility is under increasing scrutiny. The influence of surgery in the definitive management of meningioma is being re-appraised considering the rapid evolution of our understanding of the biology of meningioma. DISCUSSION: Although historically considered "benign" lesions, meningioma natural history can vary greatly, behaving with unexpectedly high recurrence rates and growth which do not always behave in accordance with their WHO grade. Histologically confirmed WHO grade 1 tumors may demonstrate unexpected recurrence, malignant transformation, and aggressive behavior, underscoring the molecular complexity and heterogeneity. CONCLUSION: As our understanding of the clinical predictive power of genomic and epigenomic factors matures, we here discuss the importance of surgical decision-making paradigms in the context of our rapidly evolving understanding of these molecular features.


Asunto(s)
Neoplasias Meníngeas , Meningioma , Humanos , Meningioma/genética , Meningioma/cirugía , Meningioma/patología , Neoplasias Meníngeas/genética , Neoplasias Meníngeas/cirugía , Neoplasias Meníngeas/patología , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/cirugía , Recurrencia Local de Neoplasia/patología , Procedimientos Neuroquirúrgicos , Estudios Retrospectivos
15.
J Neurosurg Case Lessons ; 5(10)2023 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-36880509

RESUMEN

BACKGROUND: Intratumoral aneurysms in highly vascular brain tumors can complicate resection depending on their location and feasibility of proximal control. Seemingly unrelated neurological symptoms may be from vascular steal that can help alert the need for additional vascular imaging and augmenting surgical strategies. OBSERVATIONS: A 29-year-old female presented with headaches and unilateral blurred vision, secondary to a large right frontal dural-based lesion with hypointense signal thought to represent calcifications. Given these latter findings and clinical suspicion for a vascular steal phenomenon to explain the blurred vision, computed tomography angiography was obtained, revealing a 4 × 2-mm intratumoral aneurysm. Diagnostic cerebral angiography confirmed this along with vascular steal by the tumor from the right ophthalmic artery. The patient underwent endovascular embolization of the intratumoral aneurysm, followed by open tumor resection in the same setting without complication, minimal blood loss, and improvement in her vision. LESSONS: Understanding the blood supply of any tumor, but highly vascular ones in particular, and the relationship with normal vasculature is undeniably important in avoiding potentially dangerous situations and optimizing maximal safe resection. Recognition of highly vascular tumors should prompt thorough understanding of the vascular supply and relationship of intracranial vasculature with consideration of endovascular adjuncts when appropriate.

16.
Nucl Med Commun ; 44(5): 366-374, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-36897054

RESUMEN

AIM: VARSKIN provides a convenient way of calculating skin dose from predefined geometries but the models are limited to concentric shapes such as discs, cylinders and point sources. The aim of this article is to use the Geant4 Monte Carlo code to independently compare the cylindrical geometries available in VARSKIN to more realistic droplet models obtained from photography. It may then be possible to recommend an appropriate cylinder model that can be used to represent a droplet within acceptable accuracy. METHOD: Geant4 Monte Carlo code was used to model various droplets of radioactive liquid on the skin based on photographs. The dose rates were then calculated to the sensitive basal layer 70 µm beneath the surface for three droplet volumes (10, 30 and 50 µl) and 26 radionuclides. The dose rates from the cylinder models were then compared against the dose rates from the 'true' droplet models. RESULTS: The table gives the optimum cylinder dimensions that best approximate a true droplet shape for each volume. The mean bias and 95% confidence interval (CI) from the true droplet model are also quoted. CONCLUSION: The evidence from the Monte Carlo data suggests that different droplet volumes require different cylinder aspect ratios to approximate the true droplet shape. Using the cylinder dimensions in the table in software packages such as VARSKIN, dose rates from radioactive skin contamination are expected to be within ± 7.4% of a 'true' droplet model at 95% CI.


Asunto(s)
Radioisótopos , Piel , Dosis de Radiación , Método de Montecarlo , Radiometría/métodos
17.
J Neurosurg Case Lessons ; 5(4)2023 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-36692065

RESUMEN

BACKGROUND: Primary intracranial leiomyosarcomas (PILMSs) are extremely rare tumors arising from smooth muscle connective tissue. PILMSs have been shown to be associated with Epstein-Barr virus (EBV). Thus far, EBV-associated PILMS has been exclusively described in immunocompromised patients. OBSERVATIONS: A 40-year-old male presented with a 2-year history of left-sided headaches, nausea, and vomiting. Magnetic resonance imaging demonstrated a large, heterogeneously enhancing, lobulated, dura-based mass arising from the left middle cranial fossa with associated edema and mass effect. The patient underwent an uncomplicated resection of suspected meningioma; neuropathology revealed the exceedingly rare diagnosis of EBV-associated PILMS. Follow-up testing for human immunodeficiency virus (HIV) and other immunodeficiencies confirmed the patient's immunocompetent status. LESSONS: Primary intracranial smooth muscle tumors are often misdiagnosed as meningiomas due to their similar appearance on imaging. PILMSs have a poor prognosis and gross total resection is the mainstay of treatment in the absence of clear recommendations for management. Prompt diagnosis and resection are important; therefore, these tumors should be included in the differential of dura-based tumors, especially among immunocompromised patients. Although EBV-associated PILMSs usually occur in immunocompromised individuals, their presence cannot be ruled out in immunocompetent patients.

18.
New Phytol ; 238(3): 952-970, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36694296

RESUMEN

Wildfires are a global crisis, but current fire models fail to capture vegetation response to changing climate. With drought and elevated temperature increasing the importance of vegetation dynamics to fire behavior, and the advent of next generation models capable of capturing increasingly complex physical processes, we provide a renewed focus on representation of woody vegetation in fire models. Currently, the most advanced representations of fire behavior and biophysical fire effects are found in distinct classes of fine-scale models and do not capture variation in live fuel (i.e. living plant) properties. We demonstrate that plant water and carbon dynamics, which influence combustion and heat transfer into the plant and often dictate plant survival, provide the mechanistic linkage between fire behavior and effects. Our conceptual framework linking remotely sensed estimates of plant water and carbon to fine-scale models of fire behavior and effects could be a critical first step toward improving the fidelity of the coarse scale models that are now relied upon for global fire forecasting. This process-based approach will be essential to capturing the influence of physiological responses to drought and warming on live fuel conditions, strengthening the science needed to guide fire managers in an uncertain future.


Asunto(s)
Incendios , Incendios Forestales , Plantas , Fenómenos Fisiológicos de las Plantas , Agua , Carbono , Ecosistema
19.
Iowa Orthop J ; 43(2): 106-116, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38213855

RESUMEN

Background: ALIF (anterior lumbar interbody fusion) and other spinal fusion surgeries are among the most common orthopaedic procedures requiring blood transfusions. However, blood transfusions have been associated with various complications, including adverse reactions and infections. The present study aims to identify independent risk factors for blood transfusions in patients undergoing single-level ALIF specifically to better identify high risk patients and optimize perioperative management. Methods: All patients who had undergone single-level ALIF patients for the treatment of degenerative spinal conditions, excluding traumatic, pathologic, and infectious etiologies, were identified by querying a multi-institutional surgical registry from 2005 to 2018. Multi-level fusions, PLIF/TLIF, and posterior procedures were also excluded. Mann-Whitney-U-Tests were used to analyze continuous variables, while Fisher's-Exact-Tests/Bonferroni-Corrected-Tests were used for categorical variables. Multivariate logistic regression analysis with alternating backward stepwise elimination and forward entry was implemented to identify significant predictors for blood transfusions within 72 hours after incision. The predicted probabilities were used in post-regression diagnostics to generate a Receiver Operating Characteristic (ROC) curve to assess model performance. Results: 4,792 single-level ALIF patients met inclusion criteria - 183 (3.82%) had received blood transfusions within 72 hours after incision and 4,609 (96.18%) had not. Age ≥60 years (OR 1.954, p<0.001), preoperative transfusions (OR 33.758, p=0.023), extended operative times (≥197.0 minutes; 75th percentile) (OR 4.645, p<0.001), ASA≥3 (OR 1.395, p<0.001) and preoperative hematocrit levels (Hct) 30.00-37.99 (OR 1.562, p=0.016) and Hct <30.00 (OR 6.334, p<0.001) were shown to be significant independent risk factors for perioperative blood transfusions. The area under the ROC curve (AUROC; C-statistic) was 0.759 (p<0.001), indicating relatively strong discriminatory ability/predictability of the final model. Conclusion: Several independent risk factors including age ≥60 years, preoperative blood transfusions and extended operative times increased risk for blood transfusion following single-level ALIF. The present study aims to help surgeons identify high-risk patients to better communicate postoperative expectations and optimize patients to reduce the risk of transfusions and secondary complications. Level of Evidence: III.


Asunto(s)
Degeneración del Disco Intervertebral , Fusión Vertebral , Humanos , Persona de Mediana Edad , Transfusión Sanguínea , Degeneración del Disco Intervertebral/cirugía , Degeneración del Disco Intervertebral/complicaciones , Vértebras Lumbares/cirugía , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Fusión Vertebral/efectos adversos , Fusión Vertebral/métodos , Resultado del Tratamiento , Anciano , Estudios Multicéntricos como Asunto
20.
Dev Cogn Neurosci ; 58: 101158, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36368088

RESUMEN

The two studies presented in this paper seek to resolve mixed findings in research linking activity of pubertal hormones to daily adolescent outcomes. In study 1 we used a series of Confirmatory Factor Analyses to compare the fit of one and two-factor models of seven steroid hormones (n = 994 participants, 8084 samples) of the HPA and HPG axes, using data from a field study (https://www.icpsr.umich.edu/web/ICPSR/studies/38180) collected over ten consecutive weekdays in a representative sample of teens starting high school. In study 2, we fit a Bayesian model to our large dataset to explore how hormone activity was related to outcomes that have been demonstrated to be linked to mental health and wellbeing (self-reports of daily affect and stress coping). Results reveal, first that a two-factor solution of adolescent hormones showed good fit to our data, and second, that HPG activity, rather than the more often examined HPA activity, was associated with improved daily affect ratios and stress coping. These findings suggest that field research, when it is combined with powerful statistical techniques, may help to improve our understanding of the relationship between adolescent hormones and daily measures of well-being.


Asunto(s)
Salud Mental , Bienestar Psicológico , Adolescente , Humanos , Teorema de Bayes , Hormonas , Aprendizaje Automático , Estrés Psicológico/psicología
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