"They think we wear loincloths": Spatial stigma, coloniality, and physician migration in Puerto Rico.

Puerto Rico (PR) is facing an unprecedented healthcare crisis due to accelerating migration of physicians to the mainland United States (US), leaving residents with diminishing healthcare and excessively long provider wait times. While scholars and journalists have identified economic factors driving physician migration, our study analyzes the effects of spatial stigma within the broader context of coloniality as unexamined dimensions of physician loss. Drawing on 50 semi-structured interviews with physicians throughout PR and the US, we identified how stigmatizing meanings are attached to PR, its people, and its biomedical system, often incorporating colonial notions of the island's presumed backwardness, lagging medical technology, and lack of cutting-edge career opportunities. We conclude that in addition to economically motivated policies, efforts to curb physician migration should also address globally circulating ideas about PR, acknowledge their roots in coloniality, and valorize local responses to the crisis that are in danger of being lost to history.

Efectos de un programa de ejercicios en casa para pacientes sometidos a hemodiálisis un estudio exploratorio / Effects of a home exercise program for patients undergoing hemodialysis an exploratory study

Antecedentes y objetivos: Los pacientes sometidos a hemodiálisis (HD) son particularmente vulnerables debido a las comorbilidades y a los fármacos inmunosupresores. En respuesta, este estudio tuvo como objetivo evaluar un programa alternativo de ejercicio en casa implementado para mantener la forma física de los pacientes en HD. Métodos: Se propuso un programa de entrenamiento de resistencia fuera de la clínica basado en ejercicios calisténicos a aquellos pacientes en HD que participaban en un programa de ejercicio intradialítico interrumpido durante diez semanas. Se aconsejó a los pacientes que realizaran una rutina de ejercicios en casa dos días a la semana. El impacto del programa sobre la función física se evaluó mediante pruebas que medían la fuerza muscular del tren superior e inferior, la aptitud cardiorrespiratoria y la autonomía funcional. Resultados: De los 53 pacientes elegibles para el estudio, 38 aceptaron participar y fueron asignados al grupo de ejercicio (n=17) o al grupo de control (n=21). Doce participantes completaron al menos el 80% de las sesiones de ejercicio y fueron incluidos en el análisis final. La intervención no tuvo efectos significativos intragrupo en las variables evaluadas. La comparación entre grupos indicó una mejora significativa en la fuerza muscular de la parte inferior del cuerpo, a favor del grupo de ejercicio. Conclusiones: Los resultados de este estudio exploratorio indican que un programa de ejercicios en casa realizado durante diez semanas ayudó a los pacientes con HD a prevenir el deterioro de la función muscular. (AU)

On leaving: Coloniality and physician migration in Puerto Rico.

Puerto Rico (PR) has a growing physician migration problem. As of 2009, the medical workforce was composed of 14,500 physicians and by 2020 the number had been reduced to 9,000. If this migration pattern continues, the Island will not be able to meet the recommended physicians per capita ratio proposed by the World Health Organization (WHO). Existing research has focused on the personal motivations for movement to, or permanence in, a particular setting, and social variables that encourage physicians to migrate (e.g., economic conditions). Few studies have addressed the role of coloniality in fostering physician migration. In this article we examine the role of coloniality and its impact on PR's physician migration problem. The data presented in this paper stem from an NIH-funded study (1R01MD014188) that aimed to document the factors associated with physician migration from PR to the US mainland and its impact on the Island's healthcare system. The research team used qualitative interviews, surveys, and ethnographic observations. This paper focuses on the data from the qualitative interviews with 26 physicians who had migrated to the USA and ethnographic observations, which were collected and analyzed between September 2020 and December 2022. The results evidence that participants understand physician migration as a consequence of three factors: 1) the historical and multidimensional deterioration of PR, 2) the idea that the current healthcare system is rigged by politicians and insurance companies, and 3) the specific challenges faced by physicians in training on the Island. We discuss the role of coloniality in fostering these factors and how it serves as the backdrop for the problem faced by the Island.

Clinical utility of liquid biopsy and integrative genomic profiling in early-stage and oligometastatic cancer patients treated with radiotherapy.

BACKGROUND: Liquid biopsy and Integrative Genomic Profiling (IGP) are yet to be implemented into routine Radiation Oncology. Here we assess the utility of germline, tumour and circulating cell-free DNA-based genomic analyses for the clinical management of early-stage and oligometastatic cancer patients treated by precision radiotherapy. METHODS: We performed germline, tissue- and liquid biopsy NGS panels on 50 early-stage/oligometastatic cancer patients undergoing radiotherapy. We also monitored ctDNA variants in serial liquid biopsies collected during radiotherapy and follow-up and evaluated the clinical utility of such comprehensive approach. RESULTS: The integration of different genomic studies revealed that only 1/3 of the liquid biopsy variants are of tumour origin. Altogether, 55 tumour variants (affecting 3/4 of the patients) were considered potentially actionable (for treatment and prognosis), whereas potential follow-up biomarkers were identified in all cases. Germline cancer-predisposing variants were present in three patients, which would have not been eligible for hereditary cancer testing according to clinical guidelines. The presence of detectable ctDNA variants before radiotherapy was associated with progression-free survival both in oligometastatic patients and in those with early-stage. CONCLUSIONS: IGP provides both valuable and actionable information for personalised decision-making in Radiation Oncology.

Comprehensive genomic diagnosis of inherited retinal and optical nerve disorders reveals hidden syndromes and personalized therapeutic options.

PURPOSE: In the era of precision medicine, genomic characterization of blind patients is critical. Here, we evaluate the effects of comprehensive genetic analysis on the etiologic diagnosis of potentially hereditary vision loss and its impact on clinical management. METHODS: We studied 100 non-syndromic and syndromic Spanish patients with a clinical diagnosis of blindness caused by alterations on the retina, choroid, vitreous and/or optic nerve. We used a next-generation sequencing (NGS) panel (OFTALMOgenics™), developed and validated within this study, including up to 362 genes previously associated with these conditions. RESULTS: We identified the genetic cause of blindness in 45% of patients (45/100). A total of 28.9% of genetically diagnosed cases (13/45) were syndromic and, of those, in 30.8% (4/13) extraophthalmic features had been overlooked and/or not related to visual impairment before genetic testing, including cases with Mainzer-Saldino, Bardet-Biedl, mucolipidosis and MLCRD syndromes. In two additional cases-syndromic blindness had been proposed before, but not specifically diagnosed, and one patient with Heimler syndrome had been misdiagnosed as an Usher case before testing. 33.3% of the genetically diagnosed patients (15/45) had causative variants in genes targeted by clinical trials exploring the curative potential of gene therapy approaches. CONCLUSION: Comprehensive genomic testing provided clinically relevant insights in a large proportion of blind patients, identifying potential therapeutic opportunities or previously undiagnosed syndromes in 42.2% of the genetically diagnosed cases (19/45).

Multiscale constitutive model with progressive recruitment for nanofibrous scaffolds.

Biomedical applications need tailor-made scaffolds that exhibit biomimetic mechanical properties. In this context, electrospinning has emerged as a technique with promising features for their production. However, the electrospun scaffolds mechanical behavior as a function of the microstructure and nanofiber properties is still poorly understood. Besides, multiscale constitutive modeling appears as a powerful design tool, not only able to characterize electrospun structures, but also to determine the fiber properties and scaffold microstructure that would achieve the objective response. With focus in this last aspect, we developed a multiscale constitutive model for nanofibrous structures that takes into account the material constitutive properties, scaffold microstructure, and nanofiber progressive recruitment. A statistical approach of the nanofibers tortuosity with a modified Gaussian distribution was adopted, which allowed for reproducing the scaffolds macroscopic nonlinear mechanical behavior. It was observed that such behavior arises even if the nanofibers response is considered as mechanically linear. Experimental data from pressure vs. diameter inflation tests of electrospun tubular scaffolds was used to validate the model. In addition, the influence of the microstructural parameters upon the macroscopic constitutive behavior was studied. Finally, the model parameters were adjusted to obtain a vascular graft able to reproduce the mechanical response of a target natural tissue. The current study presents a step towards understanding, characterizing, and optimizing the mechanical properties of nanofibrous biomaterials.

Value of C3d assay and IgG subclass in the prediction of the flow cytometry cross-match result for renal transplantation.

The aim of this study is to compare the association and the predictive capacity of DSA MFI, complement fixing capacity (C3d assay) and IgG subclasses determination in the prediction of FCxM result. METHODS: We used cryopreserved (70C) sera from potential renal transplant recipients, containing DSA against their respective potential donors. All patients showed negative AHG-CDC CxM and either positive or negative FCxM. Class I and Class II HLA-DSA were determined by Luminex SAB. C3d were detected by Luminex (Lifecodes®Immucor), DSA IgG 1-4 subclasses were evaluated using monoclonal antibodies specific for IgG subclasses (Luminex). RESULTS: 93 donor/recipient tests were evaluated; 32 (35.9%) patients presented at least one C3d + Ab, of which only 11 (11.8%) were donor specific. At least one IgG subclass was identified in 45 samples (48.3%). Twenty-seven FCxM tests (29%) were positive. On multivariate analysis HLA mismatches, the IgG subclass detection, DSA MFI and class II PRA remain associated to FCxM whereas C3d + Ab was not associated. For the FCxM prediction, the IgG subclass detection in combination with the DSA-MFI > 2800, had the best negative predictive value 93.9 (CI 95%, 84.2-100). CONCLUSION: Neither the C3d assay nor the IgG subclasses detection alone had an adequate predictive capacity for the FCxM. In the absence of IgG subclass detection and DSA-MFI < 2000, the probability of a negative FCxM was near 94%.

Graft immunologic events in deceased donor kidney transplant recipients with preformed HLA-donor specific antibodies.

INTRODUCTION: Pretransplant donor-specific HLA alloantibodies detected with the Single Antigen Bead (SAB) assay reflect an increased risk for acute antibody-mediated rejection (AMR). We herein report the incidence of both acute AMR and acute cellular rejection (ACR) during the first year posttransplantation, in a cohort of kidney transplant recipients (KTR) of deceased donor (DD) grafts, according to their DSA status. Pretransplant DSA do not preclude DD-KT in negative CDC-XM recipients at our center. PATIENTS AND METHODS: 246 KT were performed at our center between 01/2012 and 12/2015 and 100 KTR obtained from a DD were analyzed; 24% harbored DSA by SAB assay, MFI values >500 were considered positive. All recipients received thymoglobulin induction and generic tacrolimus-based maintenance therapy. Graft biopsies were performed by protocol on months 3 and 12 as well as per indication. The incidence of AMR and ACR was correlated with the existence of pretransplant DSA. RESULTS: Overall, 34% of patients developed an acute rejection episode, 54.2% in the DSA group versus 27.6% in the non-DSA group (p=0.032), and most of these events were detected as subclinical conditions in protocol biopsies. AMR events developed in 33.3% and 19.7% (p=0.176) in the DSA and the non-DSA groups, respectively. ACR events were found in 16.6% and 6.6% (p=0.127) in the DSA and non-DSA groups, respectively. Graft function was similar between groups at the end of the 1st year posttransplant and no immunological graft loss occurred. CONCLUSION: Despite the use of depleting induction therapy and adequate tacrolimus trough levels along with MMF and steroids, a high rate of rejection events was observed during the first year post-transplantation.

Anti-HLA-DQ antibodies are highly and independently related to the C1q-binding capacity of HLA antibodies.

The complement-binding capacity of anti-HLA antibodies (HLAabs) is recognized as a key pathogenic factor. The aim of this study is to describe the patient characteristics associated to the presence of C1q+ as well as those of the Abs per se when associated to C1q binding. METHODOLOGY: This is a cross-sectional, observational, descriptive study of patients with previous sensitizing factors and awaiting a kidney transplant (KT). We determined anti-HLA antibodies and their C1q binding capacity with the C1q assay. RESULTS: Among the 55 included patients, 26 (47.2%) had at least one C1q+ anti-HLAab. A previous transplant history, a greater number of HLAabs, a greater % of class I or class II PRA, the average MFI of all HLAabs, the MFI of the dominant HLAab and the HLAab antigenic specificities against HLA-B, -C and -DQ, all proved to be risk factors associated to the presence of C1q binding HLAabs (C1q+). In the total population, were detected 1268 HLAabs, 230 (18.1%) of which were C1q+. On multivariate analysis, both HLAabs against the HLA-DQ antigenic specificity (OR 9.82 95% CI 5.4-17.6, p<0.001) and the MFI documented by LABScreen®SAB (OR 1.2% CI 1.22-1.3, p<0.001), proved to be risk factors. CONCLUSION: Anti-HLA-DQ antibodies and the MFI (LABScreen®SAB) are highly and independently related to the C1q-binding capacity of HLA antibodies.

C1Q Assay Results in Complement-Dependent Cytotoxicity Crossmatch Negative Renal Transplant Candidates with Donor-Specific Antibodies: High Specificity but Low Sensitivity When Predicting Flow Crossmatch.

The aim of the present study was to describe the association of positive flow cross match (FXM) and C1q-SAB. Methods. In this observational, cross-sectional, and comparative study, patients included had negative AHG-CDC-XM and donor specific antibodies (DSA) and were tested with FXM. All pretransplant sera were tested with C1q-SAB assay. Results. A total of 50 donor/recipient evaluations were conducted; half of them had at least one C1q+ Ab (n = 26, 52%). Ten patients (20.0%) had DSA C1q+ Ab. Twenty-five (50%) FXMs were positive. Factors associated with a positive FXM were the presence of C1q+ Ab (DSA C1q+ Ab: OR 27, 2.80-259.56, P = 0.004, and no DSA C1q+ Ab: OR 5, 1.27-19.68, P = 0.021) and the DSA LABScreen-SAB MFI (OR 1.26, 95% CI 1.06-1.49, P = 0.007). The cutoff point of immunodominant LABScreen SAB DSA-MFI with the greatest sensitivity and specificity to predict FXM was 2,300 (sensitivity: 72% and specificity: 75%). For FXM prediction, DSA C1q+ Ab was the most specific (95.8%, 85-100) and the combination of DSA-MFI > 2,300 and C1q+ Ab was the most sensitive (92.0%, 79.3-100). Conclusions. C1q+ Ab and LABScreen SAB DSA-MFI were significantly associated with FXM. DSA C1q+ Ab was highly specific but with low sensitivity.

Impact of pretransplant exposure to allosensitization factors generating HLA antibodies in the Luminex era.

AIM: To identify the frequency of exposure to sensitizing factors and evaluate the risk ascribable to each sensitizing factor generating HLAabs measured by Luminex. METHODS: This is a retrospective cohort study that included 502 transplanted patients and 51 patients on the waiting list for a deceased donor graft. Patients were divided into 4 groups according to the %PRA: 0%, 1 to 19%, 20 to 49% and ≥50%. The OR attributable to each sensitizing factor or combination were calculated. RESULTS: Of the total 553 subjects, 53.5% were male, with an average age 35.42±12.96years. 69.1% were exposed to one or more sensitizing factors; 44.8% had %PRA class I≥1 and 38.9% had %PRA class II≥1. Independently or combined, sensitizing factors persist as a risk factor for the development of a %PRA >1%, >20% or >50%. After multivariate analysis, the three sensitizing factors remained significantly associated to HLAab development. CONCLUSIONS: In spite of using a most sensitive technique such as Luminex to measure the %PRA, a clear association persists between exposure to sensitizing factors and a high %PRA. The risk increases after exposure to more than one sensitizing factor.

Shape-independent model (SHIM) approach for studying aggregation by NMR diffusometry.

NMR diffusometry has been gaining wide popularity in various areas of applied chemistry for investigating diffusion and complexation processes in solid and aqueous phases. To date, the application of this method to study aggregation phenomena proceeding beyond the dimer stage of assembly has been restricted by the need for a priori knowledge of the aggregates' shape, commonly difficult to know in practice. We describe here a comprehensive analysis of aggregation parameter-dependency on the type and shape selected for modeling assembly processes, and report for the first time a shape-independent model (designated the SHIM approach), which may be used as an alternative in cases when information on aggregates' shapes is unavailable. The model can be used for determining equilibrium aggregation parameters from self-diffusion NMR data including equilibrium self-association constant and changes in enthalpy, ΔH, and entropy, ΔS.

C1q Assay Results in Complement-Dependent Cytotoxicity Crossmatch Negative Renal Transplant Candidates with Donor-Specific Antibodies: High Specificity But Low Sensitivity When Predicting Flow Crossmatch.

In complement dependent cytotoxicity crossmatch negative renal transplant candidates with human leukocyte antigen donor-specific antibodies (DSA), both the presence of DSA C1q+ and the dominant DSA fluorescence were significantly associated with a positive flow cytometry crossmatch (FXM+). The C1q+ assay was highly specific, but had low sensitivity when predicting FXM+, so the clinical significance of a FXM+ in the absence of DSA C1q+ remains to be clarified in future studies.

Thiazotropsin aggregation and its relationship to molecular recognition in the DNA minor groove.

Aggregated states have been alluded to for many DNA minor groove binders but details of the molecule-on-molecule relationship have either been under-reported or ignored. Here we report our findings from ITC and NMR measurements carried out with AIK-18/51, a compound representative of the thiazotropsin class of DNA minor groove binders. The free aqueous form of AIK-18/51 is compared with that found in its complex with cognate DNA duplex d(CGACTAGTCG)2. Molecular self-association of AIK-18/51 is consistent with anti-parallel, face-to-face dimer formation, the building block on which the molecule aggregates. This underlying structure is closely allied to the form found in the ligand's DNA complex. NMR chemical shift and diffusion measurements yield a self-association constant Kass=(61±19)×10(3)M(-1) for AIK-18/51 that fits with a stepwise self-assembly model and is consistent with ITC data. The deconstructed energetics of this assembly process are reported with respect to a design strategy for ligand/DNA recognition.

Energetics of ligand binding to the DNA minor groove.

In the present work the decomposition of the total Gibbs free energy of ligand-DNA binding onto various physical terms was accomplished for the group of nine DNA minor groove binders (MGB ligands) differing in both structure and charge state. The decomposition protocol includes the analysis of the most complete set of physical factors known to contribute to the complexation process, viz. the net change in the number of degrees of freedom (translational, rotational, vibrations of the chemical bonds and vibrations of the ligand as a whole within the binding site), the conformational entropy, van der Waals, electrostatic and hydrophobic interactions, the polyelectrolyte contribution and the net effect of changes in the number of hydrogen bonds. All of these processes are further decomposed into the interaction with the solvent and the interaction of the ligand with DNA. The principal outcome of the decomposition is the possibility of performing a comparative analysis of the energetic contribution of various physical terms and provide an answer to the question concerning what physical factors stabilize or destabilize the complexes of MGB ligands with DNA.