Ensuring fidelity: key elements to consider in disseminating a diabetes telemanagement program for underserved Hispanic/Latinos living with type 2 diabetes.

Background: The Hispanic/Latino population has greater risk (estimated >50%) of developing type 2 diabetes (T2D) and developing it at a younger age. The American Diabetes Association estimates costs of diagnosed diabetes in 2017 was $327 billion; with medical costs 2.3x higher than patients without diabetes. The purpose of this manuscript is to describe the methodology utilized in a randomized controlled trial aimed at evaluating the efficacy of a diabetes telemanagement (DTM) program for Hispanic/Latino patients with T2D. The intent is to provide information for future investigators to ensure that this study can be accurately replicated. Methods: This study was a randomized controlled trial with 240 participants. Eligible patients (Hispanic/Latino, aged 18+, living with T2D) were randomized to Comprehensive Outpatient Management (COM) or DTM. DTM was comprised of usual care, including routine clinic visits every three months, as well as: Biometrics (a tablet, blood glucose meter, blood pressure monitor, and scale); Weekly Video Visits (facilitated in the patient's preferred language); and Educational Videos (including culturally congruent diabetes self-management education and quizzes). COM consisted of usual care including routine clinic visits every three months. For this study, COM patients received a glucometer, glucose test strips, and lancets. Establishing a therapeutic nurse-patient relationship was a fundamental component of our study for both groups. First contact (post-enrollment) centered on ensuring that patients and caregivers understood the program, building trust and rapport, creating a non-judgmental environment, determining language preference, and establishing scheduling availability (including evenings and weekends). DTM were provided with a tablet which allowed for self-paced education through videos and weekly video visits. The research team and Community Advisory Board identified appropriate educational video content, which was incorporated in diabetes educational topics. Video visits allowed us to assess patient involvement, motivation, and nonverbal communication. Communicating in Spanish, and awareness of diverse Hispanic/Latino backgrounds was critical, as using relevant and commonly-used terms can increase adherence and improve outcomes. Shared decision-making was encouraged to make realistic health care choices. Conclusion: Key elements discussed above provide a framework for future dissemination of an evidence-based DTM intervention to meet the needs of underserved Hispanic/Latino people living with T2D.

Optimal Angiographic Goal and Number of Passes for Octogenarians Undergoing Endovascular Stroke Thrombectomy.

BACKGROUND: The optimal recanalization goal and number of endovascular thrombectomy (EVT) passes for elderly patients with large vessel occlusion strokes is unclear. METHODS: Consecutive patients 80 years or older undergoing EVT were identified from 2016 to 2022 at a single center. Clinical information, procedural details, and modified treatment in cerebral ischemia (mTICI) scores were collected. Primary outcome was modified Rankin scale (mRS) at 90 days. Bivariate and multivariable analyses were conducted to assess associations between mTICI scores, EVT passes, and 90-day outcomes. RESULTS: One hundred twenty-six patients were identified. At 90 days, mTICI 2b recanalization resulted in high rates of poor outcomes (8.7% functional independence and 60.9% mortality) not significantly different from mTICI 0, 1 or 2a (median mRS 6 vs. 6, P = 0.61). Complete recanalization (mTICI 2c or 3) led to significantly better mRS outcomes at 90 days compared to mTICI 2b (median mRS 4 vs. 6, adjusted P = 0.038), with 26.8% functional independence and 37.8% mortality. In multivariable analysis, complete recanalization was significantly associated with better 90-day outcomes than mTICI 2b or lower recanalization (odds ratio 4.24 [95% Confidence interval 1.46-12.3]; P = 0.002), while the number of passes was not independently associated with worse outcomes (P = 0.98). CONCLUSIONS: For octogenarians, mTICI 2b recanalization yields limited clinical benefit and results in poor 90-day outcomes. In contrast, complete recanalization is independently associated with significantly better outcomes. Thus, once the decision is made to pursue EVT in the elderly, mTICI 2c or better recanalization should be the angiographic goal. Providers should not withhold thrombectomy passes based on age alone.

The BAND score: A simple model for upfront prediction of poor outcomes despite successful stroke thrombectomy.

BACKGROUND: While endovascular thrombectomy (EVT) is beneficial for patients with acute large vessel occlusion ischemic strokes, a significant portion of patients still do poorly despite successful recanalization. Identifying patients at high risk for poor outcomes can be helpful for future clinical trial design and optimizing acute stroke triage. METHODS: Consecutive EVT patients were identified from 2016 to 2021 at a Comprehensive Stroke Center, and clinical information was recorded. Poor outcome was defined as a 90-day modified Rankin Scale (mRS) of 4 or greater despite achieving a modified thrombolysis in cerebral infarction (mTICI) score of 2b or greater. Multivariable regression analyses were used to identify risk factors for poor outcomes, and a scoring system was constructed. RESULTS: 483 patients with successful recanalization were identified. From a randomly selected training cohort (n = 357), the 10-point BAND score was constructed from independent risk factors for poor outcomes: baseline disability (1 point: baseline mRS ≥ 2), age (1 point: 60-69 years, 2 points: 70-79 years, 3 points: 80-84 years, 4 points: 85 years or older), NIHSS (2 points: 13-17, 3 points: 18-22, and 4 points: ≥ 23), and delay from last known normal (1 point: ≥ 6 h). The BAND score was significantly associated with rates of poor outcomes (p < 0.001), and it achieved an area under the receiver-operating characteristic curve (AUC) of 0.80 (95 %CI 0.76-0.85) in our training cohort and 0.78 (95 %CI 0.70-0.86) in our validation cohort (n = 126). Overall, the BAND score had a significantly higher AUC value than the widely validated THRIVE score and the THRIVE-EVT calculation (p = 0.001 and 0.029, respectively). Among patients with high BAND scores (7 or higher), 88.2 % had poor outcomes. CONCLUSION: The BAND score is a simple tool to predict poor outcomes despite successful recanalization. Future studies are needed to confirm the BAND score's external validity.

Emerging Subspecialties in Neurology: Interventional Neurology: A Starter Guide for Neurology Residents.

Interventional neurology is a subspecialty at the cross-section of neurology, neurosurgery, and neuroradiology that uses image-guided endovascular catheter techniques to diagnose and treat neurovascular disorders. Although interventional neurology techniques have existed for decades, recent landmark trials in stroke thrombectomy have catalyzed dramatic changes to the interventional neurology field, and there is rising neurology interest and representation. Unlike other neurology subspecialties, however, interventional neurology training and fellowship applications are not standardized. Thus, it can be difficult for neurology trainees to navigate this rapidly changing and multidisciplinary field. This article seeks to provide neurology residents and residency program directors with a brief overview of the modern interventional neurology field, the current fellowship application process, and tips on how neurologists can best prepare for a career in interventional neurology. To this end, we conducted a nationwide survey of interventional neurology fellowship program directors regarding training neurologists. We distill survey responses into concrete, actionable items for neurology trainees.

COVID-19 stressors for Hispanic/Latino patients living with type 2 diabetes: a qualitative study.

Background and aim: During the early stages of the COVID-19 pandemic, nationwide lockdowns caused disruption in the diets, physical activities, and lifestyles of patients with type 2 diabetes. Previous reports on the possible association between race/ethnicity, COVID-19, and mortality have shown that Hispanic/Latino patients with type 2 diabetes who are socioeconomically disadvantaged are disproportionately affected by this novel virus. The aim of this study was to explore stressors associated with changes in diabetes self-management behaviors. Our goal was to highlight the health disparities in these vulnerable racial/ethnic minority communities and underscore the need for effective interventions. Methods and participants: Participants were enrolled in part of a larger randomized controlled trial to compare diabetes telehealth management (DTM) with comprehensive outpatient management (COM) in terms of critical patient-centered outcomes among Hispanic/Latino patients with type 2 diabetes. We conducted a thematic analysis using patient notes collected from two research nurses between March 2020 and March 2021. Two authors read through the transcripts independently to identify overarching themes. Once the themes had been identified, both authors convened to compare themes and ensure that similar themes were identified within the transcripts. Any discrepancies were discussed by the larger study team until a consensus was reached. Results: Six themes emerged, each of which can be categorized as either a source or an outcome of stress. Sources of stress associated with the COVID-19 pandemic were (1) fear of contracting COVID-19, (2) disruptions from lockdowns, and (3) financial stressors (e.g., loss of income). Outcomes of COVID-19 stressors were (1) reduced diabetes management (e.g., reduced diabetes monitoring and physical activity), (2) suboptimal mental health outcomes (e.g., anxiety and depression), and (3) outcomes of financial stressors. Conclusion: The findings indicated that underserved Hispanic/Latino patients with type 2 diabetes encountered a number of stressors that led to the deterioration of diabetes self-management behaviors during the pandemic.

Mindfulness skills and experiential avoidance as therapeutic mechanisms for treatment-resistant depression through mindfulness-based cognitive therapy and lifestyle modification.

Background/objective: The COVID-19 pandemic and consequent physical distancing has made it difficult to provide care for those with Treatment-Resistant Depression (TRD). As a secondary analysis of a clinical trial, the aim of this study was to explore potential mechanisms through which three online-delivered approaches, added to treatment as usual, improve depressive symptoms in TRD patients. Methods: The three approaches included (a) Minimal Lifestyle Intervention (MLI), (b) Mindfulness-Based Cognitive Therapy (MBCT), and (c) Lifestyle Modification Program (LMP). Sixty-six participants with TRD completed assessments pre-post intervention (mindfulness skills [FFMQ]; self-compassion [SCS]; and experiential avoidance [AAQ-II]) and pre-intervention to follow-up (depressive symptoms [BDI-II]). Data were analyzed using within-subjects regression models to test mediation. Results: Mindfulness skills mediated the effect of MBCT on depressive symptoms (ab = -4.69, 95% CI = -12.93 to-0.32), whereas the lack of experiential avoidance mediated the effect of LMP on depressive symptoms (ab = -3.22, 95% CI = -7.03 to-0.14). Conclusion: Strengthening mindfulness skills and decreasing experiential avoidance may promote recovery in patients with TRD, MBCT, and LMP have demonstrated that they may help increase mindfulness skills and decrease experiential avoidance, respectively. Future work will need to unpick the components of these interventions to help isolate active ingredients and increase optimization.

Biomarkers of sequela in adult patients convalescing from COVID-19.

Different biomarkers for SARS-CoV-2 have been linked to detection, diagnosis, treatment, disease progression, and development of new drugs and vaccines. The objective of this research was to evaluate various hematological, biochemicals, immunological, radiological and spirometric parameters in 20 adult patients convalescing from COVID-19 and their possible relationship with the clinical course of the disease. The frequencies of categorical variables were compared using the chi-square and Fisher's exact test. The levels of statistical significance were denoted in each figure legend. Two-dimensional clustering analysis was performed using MeV software from TIGR. The tests with P value of ≤ 0.05 were considered statistically significant. Most of the patients studied presented alterations in dissimilar laboratory, radiological and spirometric parameters, which were related to the clinical evolution of the disease. The results obtained show that certain hematological, biochemical, immunological and radiological parameters can be considered as biomarkers of sequela in adult COVID-19 patients, which allows their stratification, according to the degree of involvement or sequela, into three groups: I (mild degree of involvement or sequela), without lung lesions on computerized axial tomography (CT scan) and high values of IgG, C3 and hemoglobin, II (moderate degree of involvement or sequel), without lung lesions on CT scan, characterized by high levels of CD3+/CD4+ T lymphocytes and the rest of the variables with low values and III (severe degree of involvement or sequela), with lung lesions on CT scan and high values of erythrocyte sedimentation rate, monocytes and neutrophils, associated with lymphopenia and decreased concentrations of IgG and C3.

COVID-19 Conversations Within Black/Brown Minority Communities: A Stakeholder and Psychoeducation Approach Using Zoom/Facebook Live.

As communities of color are disproportionately affected by COVID-19, there is an urgent need for dissemination of timely and accurate information to community members. In this article, we describe a stakeholder approach for the implementation, evaluation, and lessons learned from COVID-19 Conversations, a program developed and delivered virtually by researchers and academics at Northwell Health. The goal of the program was to address the mental, physical, and psychosocial needs of community members. The program used Zoom/Facebook Live to deliver interactive discussions on topics ranging from health education on COVID-19 and mental health to resources for unmet social needs. This interprofessional, cross-sector collaboration highlights the importance of public health interventions aimed at reducing the spread of COVID-19 through easy online access and culturally relevant community education and outreach.

Results of Surgical Treatment for Popliteal Aneurysm.

BACKGROUND: Evaluate the results of open surgery treatment of popliteal artery aneurysms (PAAs), performed in our department for over 25 years, comparing those treated with a medial approach with those treated with a posterior approach. MATERIAL AND METHOD: A retrospective analysis of a total of 88 PAAs, performed between January 1994 and December 2018, with an average of 65 months follow-up, comparing the results of 59 patients operated by a medial approach (group 1) in which aneurysm exclusion and femoro-popliteal bypass below the knee was carried out, with 29 cases treated by a direct posterior approach (group 2) - aneurismectomy and graft interposition-. The postoperative complications, immediate and long term patency, limb salvage and mortality rate were studied. RESULTS: In group 1 the chosen material for the bypass was reversed greater saphenous vein (GSV) in 45 cases (76.3%), expanded polytetrafluoroethylene (ePTFE) grafts in 12 (20.3%) and Dacron grafts on 2 (3.4%), while in group 2, a 6 mm diameter ringed ePTFE graft was used in 27 cases (93.1%) and reversed GSV in 2 (6.9%). There were eight (13.6%) postoperative graft thrombosis in group 1, 5 (8.9%) of them needing amputation, and 1 (3.4%) graft thrombosis in group 2 (P = 0.077). During the follow up, major amputation was necessary in 2 cases (3.7%) in group 1, while there were no cases of major amputation in group 2. Mortality was 61% (36 patients) in group 1 and 27% (8 patients) in group 2 (p = 0.003), at the end of surveillance. CONCLUSION: In our experience, in the open surgical treatment of PAAs, the posterior approach could be considered as the first choice in selected cases.

Nasopharyngeal neuroglial heterotopy - Choristoma: Case report and review of the literature.

We describe the case of a nine-month-old patient with a nasopharyngeal choristoma. The case presented includes the retrospective review of the historical, radiological, surgical and histological assessment of this pathology as well as a literature review of this entity. This case was presented in an infant with difficulty feeding, nasal obstruction and failure to thrive, evaluated with flexible nasal endoscopy, CT and MRI. The lesion was then surgically removed without complications. Nasopharyngeal choristoma is a rare congenital non-malignant mass, which may present within a range of symptoms and severity according to its size, growth and location.

Relationship of white matter lesion severity with early and late outcomes after mechanical thrombectomy for large vessel stroke.

BACKGROUND: White matter lesions (WML) are associated with poor outcome after mechanical thrombectomy (MT) for large vessel stroke; the reasons are uncertain. To elucidate this issue we sought to determine the association of WML with multiple early and late outcome measures after MT. METHODS: We retrospectively analyzed 181 MT patients prospectively included in our local stroke registry (January 2012 to November 2016). Using multiple regression modeling, we assessed whether WML was independently associated with early outcomes (successful recanalization, degree of National Institutes of Health Stroke Scale (NIHSS) improvement, hemorrhagic transformation, duration of hospitalization) as well as an unfavorable 90-day modified Rankin Scale score (mRS) (≥3) and 90-day survival. Explorative analyses examined the association with the 90-day home-time and 90-day risk for hospital readmission. RESULTS: WML were not significantly associated with early outcome measure (P>0.05, each). Patients with moderate-to-severe WML more often had an unfavorable mRS (OR 2.93, 95% CI 1.04 to 8.33) and risk of death (HR 1.98, 95% CI 1.03 to 3.84) after adjustment for pertinent confounders. Patients with moderate-to-severe WML had a significantly shorter home-time (19±32 vs 47±38 days, P<0.001) and Kaplan-Meier analyses indicated a significantly greater risk for hospital readmission within 90 days (log rank P=0.045), with the most frequent reasons being recurrent stroke and transient ischemic attack. CONCLUSION: Our analyses suggest that poor outcomes among patients with moderate-to-severe WML were related to factors unrelated to procedural success and risk. WML should not be used to render treatment decisions in otherwise eligible patients. Aggressive monitoring of medical complications after MT could represent a viable strategy to improve outcome in affected patients.

Adapting a home telemonitoring intervention for underserved Hispanic/Latino patients with type 2 diabetes: an acceptability and feasibility study.

BACKGROUND: Home telemonitoring is a promising approach to optimizing outcomes for patients with Type 2 Diabetes; however, this care strategy has not been adapted for use with understudied and underserved Hispanic/Latinos (H/L) patients with Type 2 Diabetes. METHODS: A formative, Community-Based Participatory Research approach was used to adapt a home telemonitoring intervention to facilitate acceptability and feasibility for vulnerable H/L patients. Utilizing the ADAPT-ITT framework, key stakeholders were engaged over an 8-month iterative process using a combination of strategies, including focus groups and structured interviews. Nine Community Advisory Board, Patient Advisory, and Provider Panel Committee focus group discussions were conducted, in English and Spanish, to garner stakeholder input before intervention implementation. Focus groups and structured interviews were also conducted with 12 patients enrolled in a 1-month pilot study, to obtain feedback from patients in the home to further adapt the intervention. Focus groups and structured interviews were approximately 2 hours and 30 min, respectively. All focus groups and structured interviews were audio-recorded and professionally transcribed. Structural coding was used to mark responses to topical questions in the moderator and interview guides. RESULTS: Two major themes emerged from qualitative analyses of Community Advisory Board/subcommittee focus group data. The first major theme involved intervention components to maximize acceptance/usability. Subthemes included tablet screens (e.g., privacy/identity concerns; enlarging font sizes; lighter tablet to facilitate portability); cultural incongruence (e.g., language translation/literacy, foods, actors "who look like me"); nursing staff (e.g., ensuring accessibility; appointment flexibility); and, educational videos (e.g., the importance of information repetition). A second major theme involved suggested changes to the randomized control trial study structure to maximize participation, including a major restructuring of the consenting process and changes designed to optimize recruitment strategies. Themes from pilot participant focus group/structured interviews were similar to those of the Community Advisory Board such as the need to address and simplify a burdensome consenting process, the importance of assuring privacy, and an accessible, culturally congruent nurse. CONCLUSIONS: These findings identify important adaptation recommendations from the stakeholder and potential user perspective that should be considered when implementing home telemonitoring for underserved patients with Type 2 Diabetes. TRIAL REGISTRATION: NCT03960424; ClinicalTrials.gov (US National Institutes of Health). Registered 23 May 2019. Registered prior to data collection. https://www.clinicaltrials.gov/ct2/show/NCT03960424?term=NCT03960424&draw=2&rank=1.

Effectiveness of a healthy lifestyle promotion program as adjunctive teletherapy for treatment-resistant major depression during COVID 19 pandemic: A randomized clinical trial protocol.

INTRODUCTION: Treatment-resistant depression (TRD) has a high prevalence and can be exacerbated by poor physical health and economic hardships, which have become common stressors during the current COVID-19 pandemic. The therapeutic approaches used to treat these patients are not always available, may be not be accepted by some patients, and often require face-to-face interactions. OBJECTIVE: The main aim of this study will be to evaluate the effectiveness of an Internet-based adjuvant lifestyle-based intervention for patients with TRD. METHODS: This will be a parallel, randomized, and controlled clinical trial. A total of 180 patients with TRD will be randomly allocated (1:1:1) to 1 of 3 groups: treatment prescribed by the mental health team and written suggestions for lifestyle changes (placebo control group); treatment prescribed by the mental health team, written suggestions for lifestyle changes, and an 8-week mindfulness-based cognitive therapy program (active control group); or treatment prescribed by the mental health team, written suggestions for lifestyle changes, and an 8-week lifestyle change promotion program (intervention group). We will perform this study during the COVID-19 pandemic, and will administer interventions by teletherapy, and contact participants by telephone calls, text messages, and/or teleconferences. We will collect patient data using questionnaires administered at baseline, immediately after the intervention, and after 6 and 12 months. The primary outcome will be score on the Beck Depression Inventory-II. The secondary outcomes will be score on the Clinical Global Impressions Scale (used to quantify and track patient progress and treatment response over time) and health-related quality of life measured using the European Quality of Life-5 Dimensions Questionnaire. DISCUSSION: Patients with TRD are especially vulnerable when face-to-face psychotherapy is unavailable. The main strength of the proposed study is the novelty of the intervention to be used as an adjuvant therapy. Our results may provide guidance for treatment of patients with TRD in future situations that require lockdown measures. CLINICALTRIALS REGISTRATION NUMBER: NCT04428099.

Contrasting effects of B cell depletion on CD4+ and CD8+ memory T cell responses generated after transplantation.

Alloreactive memory T cells play a key role in transplantation by accelerating allograft rejection and preventing tolerance induction. Some studies using µMT mice, which are constitutionally devoid of B cells, showed that B cells were required for the generation of memory T cells after allotransplantation. However, whether B cell depletion in normal adult mice has the same effect on memory responses by CD4+ and CD8+ T cells activated after transplantation has not been thoroughly investigated. In this study, we tested the effect of anti-CD20 antibody-mediated B cell depletion on CD4+ and CD8+ memory T cell alloresponses after skin transplantation in wild-type mice. We found that B cell depletion prevented the development of memory alloresponses by CD4+ T cells but enhanced that of CD8+ memory T cells. Next, we tested the influence of B cell depletion on hematopoietic chimerism. In OT-II CD4+ anti-OVA TCR transgenic mice sensitized to ovalbumin antigen, B cell depletion also impaired allospecific memory T cell responses and thereby enhanced donor hematopoietic chimerism and T cell deletion after bone marrow transplantation. This study underscores the complexity of the relationships between B and T cells in the generation and reactivation of different memory T cell subsets after transplantation.

COMPARATIVE ANALYSIS OF SURGICAL HEMOSTATIC SPONGES IN LIVER INJURY: STUDY IN RATS.

BACKGROUND: Obtaining effective hemostasis either in the traumatic or surgical lesions of parenchymal viscera, especially the liver, has always been a challenge. AIM: Comparative study between the use of different hemostatic sponges in hepatic wound and their capacity of integration to cells in a short period. METHODS: Fifteen Wistar rats were divided into three groups. Through laparotomy a standardized wound in hepatic right lobe was made. The animals were treated with three sponges, being gelatin in group I, equine collagen in group II, and oxidized cellulose in group III. The hemostatic capacity was analysed. On the 7º day after surgery samples for histology analysis (H&E and picrosirius) were collected for inflammatory evaluation and collagen quantification (types I and III) with polarized microscopy. RESULTS: All materials used had similar haemostatic effects, with no significant difference in hemostasis time. In the assessment of tissue repair and adhesions provoked, as well as analysis of the inflammatory process, the gelatin sponge presented greater inflammation and adhesions to the contiguous structures to the procedure in relation to the other groups. CONCLUSION: Animals which had their wounds treated with collagen and regenerated cellulose sponges presented better results in relationship to the ones treated with gelatin sponge.

Teores de cromo ligados aos óxidos de ferro em áreas de descarte de lodo de curtume / Chromium contents linked to iron oxide at areas with tannery sludge disposal

RESUMO O descarte de resíduos de lodo de curtume no solo tem sido um problema ambiental devido aos altos teores de cromo. O objetivo deste trabalho foi avaliar a dinâmica dos óxidos de ferro e os teores de cromo ligados a esses minerais em áreas de descarte de resíduos de curtume. Para isso, foram determinados os teores de ferro e cromo extraídos por oxalato de amônio dos óxidos de baixa cristalinidade e por ditionito-citrato-bicarbonato (DCB) dos óxidos cristalinos na fração argila do solo. Esses teores variaram entre 3,5 e 4,1 mg kg-1 nos tratamentos sem aplicação de lodo de curtume e entre 19,9 e 56,8 mg kg-1 nos com adição de lodo. Os teores de cromo extraídos dos óxidos cristalinos variaram entre 21,3 e 23,3 mg kg-1 nos tratamentos sem aplicação de lodo e entre 46,4 e 103,0 mg kg-1 nos com uso de lodo de curtume. A aplicação desse material proporcionou um aumento na relação do ferro extraído do óxido de ferro e o ferro extraído com o ditionito (Feo/Fed) dos óxidos da área de descarte, o que evidencia uma diminuição da cristalinidade dos óxidos. Foi encontrada uma redução na relação do ferro extraído com o ditionito e do cromo extraído com o ditionito (Fed/Crd), o que mostra a substituição do ferro pelo cromo nos óxidos, evidenciando uma troca isomórfica. Essa alteração pode ser uma alternativa para a retenção de cromo pelo solo com grande força.

ABSTRACT The tannery sludge disposal in the soil has been a serious environmental problem due to the high chromium concentrations. The aim of this study was to evaluate the iron oxides dynamic and chromium concentrations linked to these minerals in areas of tannery sludge disposal. So, concentration of iron and chromium extracted with ammonium oxalate from oxides with low crystallinity and with dithionite-citrate-bicarbonate from the crystalline oxides in the clay fraction was evaluated. The concentration of chromium extracted from the iron oxides with low crystallinity varied between 3.5 and 4.1 mg kg-1 in the treatments without application of tannery, and between 19.9 and 56.8 mg kg-1 in the treatments with tannery application. The concentration of chromium extracted from the crystalline oxides varied between 21.3 and 23.3 mg kg-1 in the treatments without application of tannery sludge, and between 46.4 and 103.0 mg kg-1 in the treatments with tannery. The application of tannery promoted an increase in the relation between the iron extracted from the iron oxides and the iron extracted with dithionite (Feo/Fed) and the oxides from the disposal area, which is an evidence of the oxide crystallinity decrease. A reduction was found in the relation between the iron extracted with dithionite and the chromium extracted with dithionite (Fed/Crd), what shows the substitution of the iron by chromium in the oxides, emphasizing an isomorphic substitution. This isomorphic substitution can be an alternative to maintain the chromium in the soil with strong retention.

Comparative analysis of surgical hemostatic sponges in liver injury: study in rats / Análise comparativa de esponjas hemostáticas cirúrgicas em ferimento de fígado: estudo em ratos

ABSTRACT Background Obtaining effective hemostasis either in the traumatic or surgical lesions of parenchymal viscera, especially the liver, has always been a challenge. Aim: Comparative study between the use of different hemostatic sponges in hepatic wound and their capacity of integration to cells in a short period. Methods: Fifteen Wistar rats were divided into three groups. Through laparotomy a standardized wound in hepatic right lobe was made. The animals were treated with three sponges, being gelatin in group I, equine collagen in group II, and oxidized cellulose in group III. The hemostatic capacity was analysed. On the 7º day after surgery samples for histology analysis (H&E and picrosirius) were collected for inflammatory evaluation and collagen quantification (types I and III) with polarized microscopy. Results: All materials used had similar haemostatic effects, with no significant difference in hemostasis time. In the assessment of tissue repair and adhesions provoked, as well as analysis of the inflammatory process, the gelatin sponge presented greater inflammation and adhesions to the contiguous structures to the procedure in relation to the other groups. Conclusion: Animals which had their wounds treated with collagen and regenerated cellulose sponges presented better results in relationship to the ones treated with gelatin sponge.

RESUMO Racional A obtenção de hemostasia eficaz nas lesões traumáticas ou cirúrgicas de vísceras parenquimatosas, em especial do fígado, sempre foi desafiante. Objetivo: Comparar o uso de hemostáticos absorvíveis em ferimento hepático quanto à capacidade hemostática e de integração aos tecidos em curto prazo. Métodos: Foram utilizados 15 ratos Wistar separados em três grupos. Foi realizada laparotomia e ferimento padronizado em lobo hepático direito. Os animais do grupo I foram tratados com esponja de gelatina sobre os ferimentos; os do grupo II com esponja de colágeno equino, e os do grupo III com celulose regenerada oxidada. Na ocasião foi estudada a capacidade hemostática. No 7º dia de pós-operatório nova laparotomia foi realizada e foram coletadas amostras para estudos histológicos (H&E e picrosirius) avaliando os processos por microscopia ótica e de polarização para quantificação de colágeno (tipos I e III). Resultados: Todos os materiais usados apresentaram efeitos hemostáticos semelhantes, não havendo diferença significativa no tempo de hemostasia. Na avaliação da reparação tecidual e aderências provocadas, assim como análise do processo inflamatório, os tratados com esponja de gelatina apresentaram maior inflamação e aderências às estruturas contíguas ao procedimento em relação aos outros grupos. Conclusão: Os animais tratados com a esponja de colágeno e celulose regenerada apresentaram resultados melhores que aqueles com esponja de gelatina.

Role of Memory T Cells in Allograft Rejection and Tolerance.

Memory T cells are characterized by their low activation threshold, robust effector functions, and resistance to conventional immunosuppression and costimulation blockade. Unlike their naïve counterparts, memory T cells reside in and recirculate through peripheral non-lymphoid tissues. Alloreactive memory T cells are subdivided into different categories based on their origins, phenotypes, and functions. Recipients whose immune systems have been directly exposed to allogeneic major histocompatibility complex (MHC) molecules display high affinity alloreactive memory T cells. In the absence of any prior exposure to allogeneic MHC molecules, endogenous alloreactive memory T cells are regularly generated through microbial infections (heterologous immunity). Regardless of their origin, alloreactive memory T cells represent an essential element of the allograft rejection process and a major barrier to tolerance induction in clinical transplantation. This article describes the different subsets of alloreactive memory T cells involved in transplant rejection and examine their generation, functional properties, and mechanisms of action. In addition, we discuss strategies developed to target deleterious allospecific memory T cells in experimental animal models and clinical settings.

Allorecognition by T Lymphocytes and Allograft Rejection.

Recognition of donor antigens by recipient T cells in secondary lymphoid organs initiates the adaptive inflammatory immune response leading to the rejection of allogeneic transplants. Allospecific T cells become activated through interaction of their T cell receptors with intact allogeneic major histocompatibility complex (MHC) molecules on donor cells (direct pathway) and/or donor peptides presented by self-MHC molecules on recipient antigen-presenting cells (APCs) (indirect pathway). In addition, recent studies show that alloreactive T cells can also be stimulated through recognition of allogeneic MHC molecules displayed on recipient APCs (MHC cross-dressing) after their transfer via cell-cell contact or through extracellular vesicles (semi-direct pathway). The specific allorecognition pathway used by T cells is dictated by intrinsic and extrinsic factors to the allograft and can influence the nature and magnitude of the alloresponse and rejection process. Consequently, various organs and tissues such as skin, cornea, and solid organ transplants are recognized differently by pro-inflammatory T cells through these distinct pathways, which may explain why these grafts are rejected in a different fashion. On the other hand, the mechanisms by which anti-inflammatory regulatory T cells (Tregs) recognize alloantigen and promote transplantation tolerance are still unclear. It is likely that thymic Tregs are activated through indirect allorecognition, while peripheral Tregs recognize alloantigens in a direct fashion. As we gain insights into the mechanisms underlying allorecognition by pro-inflammatory and Treg cells, novel strategies are being designed to prevent allograft rejection in the absence of ongoing immunosuppressive drug treatment in patients.

Donor exosomes rather than passenger leukocytes initiate alloreactive T cell responses after transplantation.

Transplantation of allogeneic organs and tissues represents a lifesaving procedure for a variety of patients affected with end-stage diseases. Although current immunosuppressive therapy prevents early acute rejection, it is associated with nephrotoxicity and increased risks for infection and neoplasia. This stresses the need for selective immune-based therapies relying on manipulation of lymphocyte recognition of donor antigens. The passenger leukocyte theory states that allograft rejection is initiated by recipient T cells recognizing donor major histocompatibility complex (MHC) molecules displayed on graft leukocytes migrating to the host's lymphoid organs. We revisited this concept in mice transplanted with allogeneic skin, heart, or islet grafts using imaging flow cytometry. We observed no donor cells in the lymph nodes and spleen of skin-grafted mice, but we found high numbers of recipient cells displaying allogeneic MHC molecules (cross-dressed) acquired from donor microvesicles (exosomes). After heart or islet transplantation, we observed few donor leukocytes (100 per million) but large numbers of recipient cells cross-dressed with donor MHC (>90,000 per million). Last, we showed that purified allogeneic exosomes induced proinflammatory alloimmune responses by T cells in vitro and in vivo. Collectively, these results suggest that recipient antigen-presenting cells cross-dressed with donor MHC rather than passenger leukocytes trigger T cell responses after allotransplantation.