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1.
Artículo en Inglés | MEDLINE | ID: mdl-38946581

RESUMEN

Current tissue engineering methods utilize chondrocytes primarily from costal or articular sources. Despite the robust mechanical properties of neocartilages sourced from these cells, the lack of elasticity and invasiveness of cell collection from these sources negatively impact clinical translation. These limitations invited the exploration of naturally elastic auricular cartilage as an alternative cell source. This study aimed to determine if auricular chondrocytes can be used for tissue engineering scaffold-free neocartilage constructs and assess their biomechanical properties. Neocartilages were successfully generated from a small quantity of primary neonatal auricular chondrocytes of three minipig donors (N=3). Neocartilage constructs had Instantaneous moduli (Ei) of 200.5 kPa ± 43.34 and 471.9 kPa ± 92.8 at 10% and 20% strain, respectively. TE constructs' relaxation moduli (Er) were 36.99 kPa ± 6.47 Er and 110.3 kPa ± 16.99 at 10% and 20% strain, respectively. The Young's modulus was 2.0 MPa ± 0.63, and the ultimate tensile strength (UTS) was 0.619 MPa ± 0.177. Auricular chondrocyte-derived neocartilages contained 0.144 ug ± 0.011 collagen, 0.185 ug ± 0.002 glycosaminoglycans per ug dry weight, and 1.7e-3 ug elastin per ug dry weight. In conclusion, this study shows that auricular chondrocytes can be used as a reliable and easily accessible cell source for tissue engineering of biomimetic and mechanically robust elastic neocartilage implants.

3.
J Neurol Sci ; 459: 122946, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38493733

RESUMEN

BACKGROUND: The ability to recognize and address bias is an important communication skill not typically addressed during training. We describe the design of an educational curriculum that aims to identify and change behavior related to diversity, equity, and inclusion (DEI). "DEI at the Bedside" uses the existing infrastructure of bedside teaching and provides a tool to normalize DEI discussions and develop skills to address bias during a neurology inpatient rotation. METHODS: As part of traditional clinical rounds, team members on an inpatient service shared experiences with DEI topics, including bias. The team developed potential responses should they encounter a similar situation in the future. We report the results of our needs assessment and curriculum development to evaluate the feasibility of incorporating a DEI educational curriculum in the neurology inpatient setting. RESULTS: Forty-two DEI experiences were recorded. Medical students were the most frequent discussants (44%). Direction of bias occurred between healthcare team members (33%), against patients (31%), and patients against healthcare team members (28%). Experiences ranged from microaggressions to explicit comments of racism, sexism, and homophobia. CONCLUSIONS: Based on needs assessment data, we developed a DEI educational curriculum for the inpatient neurology setting aimed to improve knowledge and skills related to DEI topics as well as to normalize conversation of DEI in the clinical setting. Additional study will demonstrate whether this initiative translates into measurable and sustained improvement in knowledge of how bias and disparity show up in the clinical setting and behavioral intent to discuss and address them.


Asunto(s)
Educación Médica , Neurología , Humanos , Diversidad, Equidad e Inclusión , Pacientes Internos , Comunicación
4.
J Am Heart Assoc ; 13(7): e031313, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38529656

RESUMEN

There are now abundant data demonstrating disparities in acute stroke management and prognosis; however, interventions to reduce these disparities remain limited. This special report aims to provide a critical review of the current landscape of disparities in acute stroke care and highlight opportunities to use implementation science to reduce disparities throughout the early care continuum. In the prehospital setting, stroke symptom recognition campaigns that have been successful in reducing prehospital delays used a multilevel approach to education, including mass media, culturally tailored community education, and professional education. The mobile stroke unit is an organizational intervention that has the potential to provide more equitable access to timely thrombolysis and thrombectomy treatments. In the hospital setting, interventions to address implicit biases among health care providers in acute stroke care decision-making are urgently needed as part of a multifaceted approach to advance stroke equity. Implementing stroke systems of care interventions, such as evidence-based stroke care protocols at designated stroke centers, can have a broader public health impact and may help reduce geographic, racial, and ethnic disparities in stroke care, although further research is needed. The long-term impact of disparities in acute stroke care cannot be underestimated. The consistent trend of longer time to treatment for Black and Hispanic people experiencing stroke has direct implications on long-term disability and independence after stroke. A learning health system model may help expedite the translation of evidence-based interventions into clinical practice to reduce disparities in stroke care.


Asunto(s)
Disparidades en Atención de Salud , Accidente Cerebrovascular , Humanos , Negro o Afroamericano , Hispánicos o Latinos , Pronóstico , Grupos Raciales , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/terapia , Estados Unidos
5.
Neurology ; 102(2): e208095, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38165351

RESUMEN

Our perspective as clinicians is focused on the patient; however, when patients present with severe stroke, we rely on family or surrogate decision-makers to assist with decisions regarding life-sustaining treatment. In this issue of Neurology®, Morgenstern et al.1 report on long-term psychological distress among surrogate decision-makers for patients with severe stroke. The authors used validated measures of post-traumatic stress, anxiety, and depression among family surrogate decision-makers and found between 17% and 28% of surrogates to have high scores on measures of psychological distress. One or more high levels of the psychological outcomes were found in 17%-43% of surrogates, 2 or more were found in 12%-27%, and all 3 were found in 5%-16% of surrogates. The study population included a biethnic community of predominantly nonimmigrant Mexican American (MA) and non-Hispanic White (NHW) persons, and outcomes were evaluated by ethnicity. Symptoms of post-traumatic stress remained worse among MA surrogates in the fully adjusted model; however, they were no longer significant for anxiety or depression after adjustment. The authors conclude that psychological distress is common among family surrogate decision-makers in the year after stroke and may be worse among MA surrogates. The authors propose that efforts are needed to support family members of all ethnic groups after severe stroke.


Asunto(s)
Distrés Psicológico , Accidente Cerebrovascular , Humanos , Ansiedad , Trastornos de Ansiedad , Accidente Cerebrovascular/terapia , Toma de Decisiones
6.
Neurology ; 102(2): e208014, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38165334

RESUMEN

BACKGROUND AND OBJECTIVES: Evidence of the so-called "obesity paradox," which refers to the protective effect and survival benefit of obesity in patients with spontaneous intracerebral hemorrhage (ICH), remains controversial. This study aims to determine the association between body mass index (BMI) and functional outcomes in patients with ICH and whether it is modified by race/ethnicity. METHODS: Included individuals were derived from the Ethnic/Racial Variations of Intracerebral Hemorrhage study, which prospectively recruited 1,000 non-Hispanic White, 1,000 non-Hispanic Black, and 1,000 Hispanic patients with spontaneous ICH. Only patients with available BMI were included. The primary outcome was 90-day mortality. Secondary outcomes were mortality at discharge, modified Rankin Scale (mRS), Barthel Index, and self-reported health status measures at 90 days. Associations between BMI and ICH outcomes were assessed using univariable and multivariable logistic, ordinal, and linear regression models, as appropriate. Sensitivity analyses after excluding frail patients and by patient race/ethnicity were performed. RESULTS: A total of 2,841 patients with ICH were included. The median age was 60 years (interquartile range 51-73). Most patients were overweight (n = 943; 33.2%) or obese (n = 1,032; 36.3%). After adjusting for covariates, 90-day mortality was significantly lower among overweight and obese patients than their normal weight counterparts (adjusted odds ratio [aOR] = 0.71 [0.52-0.98] and aOR = 0.70 [0.50-0.97], respectively). Compared with patients with BMI <25 kg/m2, those with BMI ≥25 kg/m2 had better 90-day mRS (aOR = 0.80 [CI 0.67-0.95]), EuroQoL Group 5-Dimension (EQ-5D) (aß = 0.05 [0.01-0.08]), and EQ-5D VAS (aß = 3.80 [0.80-6.98]) scores. These differences persisted after excluding withdrawal of care patients. There was an inverse relationship between BMI and 90-day mortality (aOR = 0.97 [0.96-0.99]). Although non-Hispanic White patients had significantly higher 90-day mortality than non-Hispanic Black and Hispanic (26.6% vs 19.5% vs 18.0%, respectively; p < 0.001), no significant interactions were found between BMI and race/ethnicity. No significant interactions between BMI and age or sex for 90-day mortality were found, whereas for 90-day mRS, there was a significant interaction with age (pinteraction = 0.004). CONCLUSION: We demonstrated that a higher BMI is associated with decreased mortality, improved functional outcomes, and better self-reported health status at 90 days, thus supporting the paradoxical role of obesity in patients with ICH. The beneficial effect of high BMI does not seem to be modified by race/ethnicity or sex, whereas age may play a significant role in patient functional outcomes.


Asunto(s)
Etnicidad , Sobrepeso , Humanos , Persona de Mediana Edad , Índice de Masa Corporal , Obesidad/complicaciones , Hemorragia Cerebral/complicaciones
7.
Ann Neurol ; 95(2): 347-361, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37801480

RESUMEN

OBJECTIVE: This study was undertaken to examine averted stroke in optimized stroke systems. METHODS: This secondary analysis of a multicenter trial from 2014 to 2020 compared patients treated by mobile stroke unit (MSU) versus standard management. The analytical cohort consisted of participants with suspected stroke treated with intravenous thrombolysis. The main outcome was a tissue-defined averted stroke, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours attributed to thrombolysis and no acute infarction/hemorrhage on imaging. An additional outcome was stroke with early symptom resolution, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours attributed to thrombolysis. RESULTS: Among 1,009 patients with a median last known well to thrombolysis time of 87 minutes, 159 (16%) had tissue-defined averted stroke and 276 (27%) had stroke with early symptom resolution. Compared with standard management, MSU care was associated with more tissue-defined averted stroke (18% vs 11%, adjusted odds ratio [aOR] = 1.82, 95% confidence interval [CI] = 1.13-2.98) and stroke with early symptom resolution (31% vs 21%, aOR = 1.74, 95% CI = 1.12-2.61). The relationships between thrombolysis treatment time and averted/early recovered stroke appeared nonlinear. Most models indicated increased odds for stroke with early symptom resolution but not tissue-defined averted stroke with earlier treatment. Additionally, younger age, female gender, hyperlipidemia, lower National Institutes of Health Stroke Scale, lower blood pressure, and no large vessel occlusion were associated with both tissue-defined averted stroke and stroke with early symptom resolution. INTERPRETATION: In optimized stroke systems, 1 in 4 patients treated with thrombolysis recovered within 24 hours and 1 in 6 had no demonstrable brain injury on imaging. ANN NEUROL 2024;95:347-361.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular , Humanos , Femenino , Activador de Tejido Plasminógeno/uso terapéutico , Fibrinolíticos/uso terapéutico , Estudios Prospectivos , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/complicaciones , Hemorragia/complicaciones , Terapia Trombolítica/métodos , Resultado del Tratamiento , Isquemia Encefálica/tratamiento farmacológico
8.
Int J Mol Sci ; 24(23)2023 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-38069418

RESUMEN

Because equine tendinopathies are slow to heal and often recur, therapeutic strategies are being considered that aid tendon repair. Given the success of utilizing vitamin C to promote tenogenesis in other species, we hypothesized that vitamin C supplementation would produce dose-dependent improvements in the tenogenic properties of tendon proper (TP) and peritenon (PERI) cells of the equine superficial digital flexor tendon (SDFT). Equine TP- and PERI-progenitor-cell-seeded fibrin three-dimensional constructs were supplemented with four concentrations of vitamin C. The gene expression profiles of the constructs were assessed with 3'-Tag-Seq and real-time quantitative polymerase chain reaction (RT-qPCR); collagen content and fibril ultrastructure were also analyzed. Moreover, cells were challenged with dexamethasone to determine the levels of cytoprotection afforded by vitamin C. Expression profiling demonstrated that vitamin C had an anti-inflammatory effect on TP and PERI cell constructs. Moreover, vitamin C supplementation mitigated the degenerative pathways seen in tendinopathy and increased collagen content in tendon constructs. When challenged with dexamethasone in two-dimensional culture, vitamin C had a cytoprotective effect for TP cells but not necessarily for PERI cells. Future studies will explore the effects of vitamin C on these cells during inflammation and within the tendon niche in vivo.


Asunto(s)
Tendinopatía , Tendones , Animales , Caballos , Tendones/metabolismo , Colágeno/metabolismo , Ingeniería de Tejidos/métodos , Tendinopatía/tratamiento farmacológico , Tendinopatía/metabolismo , Ácido Ascórbico/farmacología , Ácido Ascórbico/metabolismo , Dexametasona/farmacología , Dexametasona/metabolismo
9.
Nutrients ; 15(17)2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37686793

RESUMEN

Lifestyle modifications after stroke are associated with better risk factor control and lower mortality. The primary objective of this study was to describe the knowledge of American Heart Association (AHA) recommendations for diet and exercise in survivors of stroke and transient ischemic attack (TIA). The secondary objectives were to describe their diet and exercise behaviors, self-efficacy (SE), behavioral intent (BI), stage of change, and barriers to change. Data are described from participants enrolled in a prospective educational intervention in mild stroke/TIA survivors. A multiple-choice questionnaire ascertained knowledge of AHA recommendations for diet and exercise, nutrition and physical activity behavior, SE, BI, stage of change, and barriers to change. Twenty-eight stroke/TIA survivors, with a mean age of 61.7 ± 11.8 years, completed questionnaires during their acute hospitalization. Participants underestimated the recommended intake of fruits, vegetables, whole grains, and participation in aerobic exercise and overestimated the recommended intake of sugar and salt. SE demonstrated a significant positive association with combined behavior scores (rs = 0.36, p = 0.043). Greater knowledge of the AHA recommendations was not associated with healthier behavior, greater SE, higher BI, or more advanced stage of change. The gaps between AHA recommendations and stroke/TIA patient knowledge identifies an area for potential intervention in stroke prevention and recovery.


Asunto(s)
Ataque Isquémico Transitorio , Accidente Cerebrovascular , Humanos , Persona de Mediana Edad , Anciano , Proyectos Piloto , Estudios Prospectivos , Educación en Salud , Ejercicio Físico
10.
Transl Stroke Res ; 2023 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-37308620

RESUMEN

Deep intracerebral hemorrhage (ICH) exerts a direct force on corticospinal tracts (CST) causing shape deformation. Using serial MRI, Generalized Procrustes Analysis (GPA), and Principal Components Analysis (PCA), we temporally evaluated the change in CST shape. Thirty-five deep ICH patients with ipsilesional-CST deformation were serially imaged on a 3T-MRI with a median imaging time of day-2 and 84 of onset. Anatomical and diffusion tensor images (DTI) were acquired. Using DTI color-coded maps, 15 landmarks were drawn on each CST and the centroids were computed in 3 dimensions. The contralesional-CST landmarks were used as a reference. The GPA outlined the shape coordinates and we superimposed the ipsilesional-CST shape at the two-time points. A multivariate PCA was applied to identify eigenvectors associated with the highest percentile of change. The first three principal components representing CST deformation along the left-right (PC1), anterior-posterior (PC2), and superior-inferior (PC3) respectively were responsible for 57.9% of shape variance. The PC1 (36.1%, p < 0.0001) and PC3 (9.58%, p < 0.01) showed a significant deformation between the two-time points. Compared to the contralesional-CST, the ipsilesional PC scores were significantly (p < 0.0001) different only at the first-timepoint. A significant positive association between the ipsilesional-CST deformation and hematoma volume was observed. We present a novel method to quantify CST deformation caused by ICH. Deformation most often occurs in left-right axis (PC1) and superior-inferior (PC3) directions. As compared to the reference, the significant temporal difference at the first time point suggests CST restoration over time.

11.
Int J Stroke ; 18(10): 1209-1218, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37337357

RESUMEN

BACKGROUND: Few data exist on acute stroke treatment in patients with pre-existing disability (PD) since they are usually excluded from clinical trials. A recent trial of mobile stroke units (MSUs) demonstrated faster treatment and improved outcomes, and included PD patients. AIM: To determine outcomes with tissue plasminogen activator (tPA), and benefit of MSU versus management by emergency medical services (EMS), for PD patients. METHODS: Primary outcomes were utility-weighted modified Rankin Scale (uw-mRS). Linear and logistic regression models compared outcomes in patients with versus without PD, and PD patients treated by MSU versus standard management by EMS. Time metrics, safety, quality of life, and health-care utilization were compared. RESULTS: Of the 1047 tPA-eligible ischemic stroke patients, 254 were with PD (baseline mRS 2-5) and 793 were without PD (baseline mRS 0-1). Although PD patients had worse 90-day uw-mRS, higher mortality, more health-care utilization, and worse quality of life than non-disabled patients, 53% returned to at least their baseline mRS, those treated faster had better outcome, and there was no increased bleeding risk. Comparing PD patients treated by MSU versus EMS, 90-day uw-mRS was 0.42 versus 0.36 (p = 0.07) and 57% versus 46% returned to at least their baseline mRS. There was no interaction between disability status and MSU versus EMS group assignment (p = 0.67) for 90-day uw-mRS. CONCLUSION: PD did not prevent the benefit of faster treatment with tPA in the BEST-MSU study. Our data support inclusion of PD patients in the MSU management paradigm.


Asunto(s)
Servicios Médicos de Urgencia , Accidente Cerebrovascular , Humanos , Fibrinolíticos/uso terapéutico , Calidad de Vida , Accidente Cerebrovascular/tratamiento farmacológico , Activador de Tejido Plasminógeno/uso terapéutico , Resultado del Tratamiento , Ensayos Clínicos como Asunto
12.
Stroke ; 54(4): e175-e187, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36748462

RESUMEN

Stroke center certification has evolved at a rapid pace and is now available at 4 different levels of service in the United States. Although certification standards provide guidance on stroke center process elements, lack of guidance on structural components such as workforce, staffing, and unit operations has resulted in heterogeneous services among hospitals credentialed at the same stroke center level. Such heterogeneity challenges public expectations and transparency about actual service capabilities within American stroke centers and in some cases may foster leniency in credentialing agency certification methods. Standards for other time-dependent diagnoses, including trauma, provide detailed guidance on structural elements that has improved patient triage and resuscitative care while enabling practitioners and administrators to more accurately gauge and plan service development to better support their communities. This scientific statement aims to provide similar structural guidance defined by each level of hospital stroke center services to reduce operational inconsistencies, to foster planning for service development, and to improve the interprofessional care of patients with acute stroke.


Asunto(s)
American Heart Association , Accidente Cerebrovascular , Humanos , Estados Unidos , Accidente Cerebrovascular/diagnóstico , Hospitales , Certificación , Crecimiento y Desarrollo
14.
Neurol Clin Pract ; 13(6): e200206, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38495079

RESUMEN

Background and Objectives: Multidisciplinary clinics have been shown to improve care. Patients with patent foramen ovale (PFO)-associated stroke need evaluation by cardiology and neurology specialists. We report our experience creating a multidisciplinary Structural Heart Brain Clinic (HBC) with a focus on patients with PFO-associated stroke. Methods: Demographic and clinical data were retrospectively collected for patients with PFO-associated ischemic stroke. Patients with PFO-associated stroke were divided into a standard care group and Heart Brain Clinic group for analysis. Outcome measures included time from stroke to PFO closure and number of clinic visits before decision regarding closure. Nonparametric analysis evaluated differences in median time to visit and clinical decision, while the chi square analysis compared differences in categorical variables between groups. Results: From February 2017 to December 2021, 120 patients were evaluated for PFO-associated stroke. The Structural HBC began in 12/2018 with coordination between Departments of Neurology and Cardiology. For this analysis, 41 patients were considered in the standard care group and 79 patients in the HBC group. During data analysis, 107 patients had received recommendations about PFO closure. HBC patients required fewer clinic visits (p = 0.001) before decision about closure; however, among patients who underwent PFO closure, there was no significant difference in weeks from stroke to PFO closure. Clinicians were more likely to recommend against PFO closure among patients seen in HBC compared with those seen in standard care (p = 0.021). Discussion: Our data demonstrate that a multidisciplinary, patient-centered approach to management of patients with PFO-associated ischemic stroke is feasible and may improve the quality of care in this younger patient population. The difference in recommendation to not pursue PFO closure between groups may reflect selection and referral bias. Additional work is needed to determine whether this approach improves other aspects of care and outcomes.

15.
JAMA Netw Open ; 5(3): e221103, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-35289861

RESUMEN

Introduction: Intracerebral hemorrhage (ICH) is the most severe subtype of stroke. Its mortality rate is high, and most survivors experience significant disability. Objective: To assess primary patient risk factors associated with mortality and neurologic disability 3 months after ICH in a large, racially and ethnically balanced cohort. Design, Setting, and Participants: This cohort study included participants from the Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) study, which prospectively recruited 1000 non-Hispanic White, 1000 non-Hispanic Black, and 1000 Hispanic patients with spontaneous ICH to study the epidemiological characteristics and genomics associated with ICH. Participants included those with uniform data collection and phenotype definitions, centralized neuroimaging review, and telephone follow-up at 3 months. Analyses were completed in November 2021. Exposures: Patient demographic and clinical characteristics as well as hospital event and imaging variables were examined, with characteristics meeting P < .20 considered candidates for a multivariate model. Elements included in the ICH score were specifically analyzed. Main Outcomes and Measures: Individual characteristics were screened for association with 3-month outcome of neurologic disability or mortality, as assessed by a modified Rankin Scale (mRS) score of 4 or greater vs 3 or less under a logistic regression model. A total of 25 characteristics were tested in the final model, which minimized the Akaike information criterion. Analyses were repeated removing individuals who had withdrawal of care. Results: A total of 2568 patients (mean [SD] age, 62.4 [14.7] years; 1069 [41.6%] women and 1499 [58.4%] men) had a 3-month outcome determination available, including death. The final logistic model had a significantly higher area under the receiver operating characteristics curve (C = 0.88) compared with ICH score alone (C = 0.76; P < .001). Among characteristics associated with neurologic disability and mortality were larger log ICH volume (OR, 2.74; 95% CI, 2.36-3.19; P < .001), older age (OR per 1-year increase, 1.04; 95% CI, 1.02-1.05; P < .001), pre-ICH mRS score (OR, 1.62; 95% CI, 1.41-1.87; P < .001), lobar location (OR, 0.22; 95% CI, 0.16-0.30; P < .001), and presence of infection (OR, 1.85; 95% CI, 1.42-2.41; P < .001). Conclusions and Relevance: The findings of this cohort study validate ICH score elements and suggest additional baseline and interim patient characteristics were associated with variation in 3-month outcome.


Asunto(s)
Hemorragia Cerebral , Accidente Cerebrovascular , Estudios de Cohortes , Femenino , Humanos , Grupos Raciales , Factores de Riesgo
16.
Adv Exp Med Biol ; 1348: 5-43, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34807414

RESUMEN

The physiology of connective tissues like tendons and ligaments is highly dependent upon the collagens and other such extracellular matrix molecules hierarchically organized within the tissues. By dry weight, connective tissues are mostly composed of fibrillar collagens. However, several other forms of collagens play essential roles in the regulation of fibrillar collagen organization and assembly, in the establishment of basement membrane networks that provide support for vasculature for connective tissues, and in the formation of extensive filamentous networks that allow for cell-extracellular matrix interactions as well as maintain connective tissue integrity. The structures and functions of these collagens are discussed in this chapter. Furthermore, collagen synthesis is a multi-step process that includes gene transcription, translation, post-translational modifications within the cell, triple helix formation, extracellular secretion, extracellular modifications, and then fibril assembly, fibril modifications, and fiber formation. Each step of collagen synthesis and fibril assembly is highly dependent upon the biochemical structure of the collagen molecules created and how they are modified in the cases of development and maturation. Likewise, when the biochemical structures of collagens or are compromised or these molecules are deficient in the tissues - in developmental diseases, degenerative conditions, or injuries - then the ultimate form and function of the connective tissues are impaired. In this chapter, we also review how biochemistry plays a role in each of the processes involved in collagen synthesis and assembly, and we describe differences seen by anatomical location and region within tendons. Moreover, we discuss how the structures of the molecules, fibrils, and fibers contribute to connective tissue physiology in health, and in pathology with injury and repair.


Asunto(s)
Colágeno , Matriz Extracelular , Tejido Conectivo , Colágenos Fibrilares , Tendones
17.
N Engl J Med ; 385(11): 971-981, 2021 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-34496173

RESUMEN

BACKGROUND: Mobile stroke units (MSUs) are ambulances with staff and a computed tomographic scanner that may enable faster treatment with tissue plasminogen activator (t-PA) than standard management by emergency medical services (EMS). Whether and how much MSUs alter outcomes has not been extensively studied. METHODS: In an observational, prospective, multicenter, alternating-week trial, we assessed outcomes from MSU or EMS management within 4.5 hours after onset of acute stroke symptoms. The primary outcome was the score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes according to a patient value system, derived from scores on the modified Rankin scale of 0 to 6, with higher scores indicating more disability). The main analysis involved dichotomized scores on the utility-weighted modified Rankin scale (≥0.91 or <0.91, approximating scores on the modified Rankin scale of ≤1 or >1) at 90 days in patients eligible for t-PA. Analyses were also performed in all enrolled patients. RESULTS: We enrolled 1515 patients, of whom 1047 were eligible to receive t-PA; 617 received care by MSU and 430 by EMS. The median time from onset of stroke to administration of t-PA was 72 minutes in the MSU group and 108 minutes in the EMS group. Of patients eligible for t-PA, 97.1% in the MSU group received t-PA, as compared with 79.5% in the EMS group. The mean score on the utility-weighted modified Rankin scale at 90 days in patients eligible for t-PA was 0.72 in the MSU group and 0.66 in the EMS group (adjusted odds ratio for a score of ≥0.91, 2.43; 95% confidence interval [CI], 1.75 to 3.36; P<0.001). Among the patients eligible for t-PA, 55.0% in the MSU group and 44.4% in the EMS group had a score of 0 or 1 on the modified Rankin scale at 90 days. Among all enrolled patients, the mean score on the utility-weighted modified Rankin scale at discharge was 0.57 in the MSU group and 0.51 in the EMS group (adjusted odds ratio for a score of ≥0.91, 1.82; 95% CI, 1.39 to 2.37; P<0.001). Secondary clinical outcomes generally favored MSUs. Mortality at 90 days was 8.9% in the MSU group and 11.9% in the EMS group. CONCLUSIONS: In patients with acute stroke who were eligible for t-PA, utility-weighted disability outcomes at 90 days were better with MSUs than with EMS. (Funded by the Patient-Centered Outcomes Research Institute; BEST-MSU ClinicalTrials.gov number, NCT02190500.).


Asunto(s)
Ambulancias , Servicios Médicos de Urgencia , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Unidades Móviles de Salud , Tiempo de Tratamiento , Activador de Tejido Plasminógeno/uso terapéutico , Anciano , Evaluación de la Discapacidad , Femenino , Humanos , Accidente Cerebrovascular Isquémico/complicaciones , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Índice de Severidad de la Enfermedad , Tomografía Computarizada por Rayos X
18.
JAMA Netw Open ; 4(8): e2121921, 2021 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-34424302

RESUMEN

Importance: Black and Hispanic individuals have an increased risk of intracerebral hemorrhage (ICH) compared with their White counterparts, but no large studies of ICH have been conducted in these disproportionately affected populations. Objective: To examine the prevalence, odds, and population attributable risk (PAR) percentage for established and novel risk factors for ICH, stratified by ICH location and racial/ethnic group. Design, Setting, and Participants: The Ethnic/Racial Variations of Intracerebral Hemorrhage Study was a case-control study of ICH among 3000 Black, Hispanic, and White individuals who experienced spontaneous ICH (1000 cases in each group). Recruitment was conducted between September 2009 and July 2016 at 19 US sites comprising 42 hospitals. Control participants were identified through random digit dialing and were matched to case participants by age (±5 years), sex, race/ethnicity, and geographic area. Data analyses were conducted from January 2019 to May 2020. Main Outcomes and Measures: Case and control participants underwent a standardized interview, physical measurement for body mass index, and genotyping for the ɛ2 and ɛ4 alleles of APOE, the gene encoding apolipoprotein E. Prevalence, multivariable adjusted odds ratio (OR), and PAR percentage were calculated for each risk factor in the entire ICH population and stratified by racial/ethnic group and by lobar or nonlobar location. Results: There were 1000 Black patients (median [interquartile range (IQR)] age, 57 [50-65] years, 425 [42.5%] women), 1000 Hispanic patients (median [IQR] age, 58 [49-69] years; 373 [37.3%] women), and 1000 White patients (median [IQR] age, 71 [59-80] years; 437 [43.7%] women). The mean (SD) age of patients with ICH was significantly lower among Black and Hispanic patients compared with White patients (eg, lobar ICH: Black, 62.2 [15.2] years; Hispanic, 62.5 [15.7] years; White, 71.0 [13.3] years). More than half of all ICH in Black and Hispanic patients was associated with treated or untreated hypertension (PAR for treated hypertension, Black patients: 53.6%; 95% CI, 46.4%-59.8%; Hispanic patients: 46.5%; 95% CI, 40.6%-51.8%; untreated hypertension, Black patients: 45.5%; 95% CI, 39.%-51.1%; Hispanic patients: 42.7%; 95% CI, 37.6%-47.3%). Lack of health insurance also had a disproportionate association with the PAR percentage for ICH in Black and Hispanic patients (Black patients: 21.7%; 95% CI, 17.5%-25.7%; Hispanic patients: 30.2%; 95% CI, 26.1%-34.1%; White patients: 5.8%; 95% CI, 3.3%-8.2%). A high sleep apnea risk score was associated with both lobar (OR, 1.68; 95% CI, 1.36-2.06) and nonlobar (OR, 1.62; 95% CI, 1.37-1.91) ICH, and high cholesterol was inversely associated only with nonlobar ICH (OR, 0.60; 95% CI, 0.52-0.70); both had no interactions with race and ethnicity. In contrast to the association between the ɛ2 and ɛ4 alleles of APOE and ICH in White individuals (eg, presence of APOE ɛ2 allele: OR, 1.84; 95% CI, 1.34-2.52), APOE alleles were not associated with lobar ICH among Black or Hispanic individuals. Conclusions and Relevance: This study found sleep apnea as a novel risk factor for ICH. The results suggest a strong contribution from inadequately treated hypertension and lack of health insurance to the disproportionate burden and earlier onset of ICH in Black and Hispanic populations. These findings emphasize the importance of addressing modifiable risk factors and the social determinants of health to reduce health disparities.


Asunto(s)
Hemorragia Cerebral/etnología , Hemorragia Cerebral/epidemiología , Hemorragia Cerebral/genética , Minorías Étnicas y Raciales/estadística & datos numéricos , Etnicidad/estadística & datos numéricos , Predisposición Genética a la Enfermedad , Factores Raciales/estadística & datos numéricos , Negro o Afroamericano/etnología , Negro o Afroamericano/genética , Negro o Afroamericano/estadística & datos numéricos , Anciano , Estudios de Casos y Controles , Etnicidad/genética , Femenino , Hispánicos o Latinos/genética , Hispánicos o Latinos/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Factores de Riesgo , Estados Unidos/epidemiología , Estados Unidos/etnología , Población Blanca/etnología , Población Blanca/genética , Población Blanca/estadística & datos numéricos
20.
Case Rep Neurol ; 12(2): 199-209, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32647526

RESUMEN

COVID-19 has been associated with a hypercoagulable state causing cardiovascular and neurovascular complications. To further characterize cerebrovascular disease (CVD) in COVID-19, we review the current literature of published cases and additionally report the clinical presentation, laboratory and diagnostic testing results of 12 cases with COVID-19 infection and concurrent CVD from two academic medical centers in Houston, TX, USA, between March 1 and May 10, 2020. To date, there are 12 case studies reporting 47 cases of CVD in COVID-19. However, only 4 small case series have described the clinical and laboratory findings in patients with COVID-19 and concurrent stroke. Viral neurotropism, endothelial dysfunction, coagulopathy and inflammation are plausible proposed mechanisms of CVD in COVID-19 patients. In our case series of 12 patients, 10 patients had an ischemic stroke, of which 1 suffered hemorrhagic transformation and two had intracerebral hemorrhage. Etiology was determined to be embolic without a clear cause identified in 6 ischemic stroke patients, while the remaining had an identifiable source of stroke. The majority of the patients had elevated inflammatory markers such as D-dimer and interleukin-6. In patients with embolic stroke of unclear etiology, COVID-19 may have played a direct or indirect role in the processes that eventually led to the strokes while in the remaining cases, it is unclear if infection contributed partially or was an incidental finding.

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