Anti-DENV-NS1 monoclonal antibody for the differential histopathological diagnosis of hemorrhagic fever caused by dengue

Dengue is the most prevalent arboviral disease in humans in tropical and subtropical regions, especially in urban areas, and can cause major epidemics. Although a self-limiting illness, it may sometimes have serious hemorrhagic manifestations, and the outcome of dengue hemorrhagic fever has similar clinical manifestations as in other infections, which could result in death. Therefore, autopsy procedures are required under certain circumstances such as in hemorrhagic fevers, sometimes to confirm or to clarify the diagnosis that may have epidemiological consequences. Normally, the Immunohistochemistry Laboratory of the Pathology Center of Adolfo Lutz Institute receives autopsy samples from different hospitals in Sao Paulo State to confirm a previous diagnosis, especially hemorrhagic fever of infectious etiology. For this diagnosis, we have been using a mouse polyclonal antibody to dengue virus that often does not provide a clear conclusion, because of background staining or no relevant immunostaining, which hampers the histopathological analysis. Accordingly, in the present study, anti-DENV-NS1 monoclonal antibody (4H2) was tested to determine its accuracy in immunohistochemical analysis. Twenty-four autopsy cases of hemorrhagic febrile syndrome showing histopathological alterations compatible with dengue disease were studied: twenty cases were confirmed by RT-PCR for DENV-2 and in four by RT-PCR for yellow fever virus. Samples from autopsied cases of deaths caused by other infectious diseases (two meningitis C and two severe acute respiratory syndrome caused by influenza A H1N1) were included as negative control cases. Positive immunostaining for DENV-NS1 was detected in 16/20 (80%) liver samples and 11/15 (73%) spleen samples from autopsied hemorrhagic dengue patients, whereas the polyclonal antibody detected DENV antigens in 12/20 (60%) liver and in 6/15 (40%) spleen samples from the same cases. Positive results were not obtained with liver biopsy samples from yellow fever or Neisseria meningitides and Flu-A cases. 4H2 mAb recognizes the native protein of the four DENV serotypes in infected cells and did not cross-react with native ZIKV- or CHKV-infected cells by immunohistochemical assay, so it is a useful tool for differential histopathological conclusion of acute febrile hemorrhagic deaths.

Evaluation of stress, burnout and hair cortisol levels in health workers at a University Hospital during COVID-19 pandemic.

In the critical context of COVID-19 pandemic, healthcare workers are on the front line, participating directly in the care, diagnosis, and treatment of patients with COVID-19. This exposes them to a higher risk of developing chronic stress, psychological distress, and any other mental health symptoms. OBJECTIVE: to evaluate stress and burnout in a health workers population and, in addition, to measure hair cortisol concentration as a current biomarker of stress. MATERIALS AND METHODS: 234 health workers from Hospital de Clínicas "José de San Martín", Buenos Aires University, were included in this study. In this population hair samples were obtained from the posterior vertex as close to the scalp as possible and the individuals completed the following surveys: perceived stress, social support, burnout scale, life event scale, and sociodemographic data. Hair cortisol was measured by an automated chemiluminescent method. The studied population was divided into three groups considering those individuals below the healthy reference sample range (< 40 pg/mg hair), within the healthy reference range (40-128 pg/mg hair) and above the reference range (> 128 pg/mg hair). This study used a transversal and observational design. RESULTS: Our results show that 40% of the studied population presented hair cortisol values outside of the healthy reference range. In the whole studied population, a direct correlation was found between hair cortisol concentration and perceived stress as well as between hair cortisol concentration and the emotional exhaustion component of burnout (r = 0.142, p = 0.030; r = 0.143, p = 0.029, respectively). 12% of the studied population showed Burnout (52% doctors and residents, 19% nurses, 19% administrative personnel). Higher values in hair cortisol levels were found in the group with burnout versus individuals without burnout (p = 0.034). Finally, a mediation analysis was performed, finding that depersonalization is a mediating variable in the relationship between self-perceived stress and hair cortisol level (F = 4.86, p = 0.0086; indirect effect IC: 0.0987-1.8840). CONCLUSION: This is the first study in which a stress biomarker such as hair cortisol is evaluated in this population and in this context. Healthcare workers are subjected to increased levels of stress and burnout. High depersonalization, emotional exhaustion, and decreased personal sense of accomplishment characterize this population. It is the responsibility of the health authorities to implement strategies to manage this psychological emergency.

Hair cortisol: A new tool for evaluating stress in programs of stress management.

AIMS: Longitudinal and experimental studies have shown that chronic stress contributes to the onset and progression of different diseases. Although it is not possible to eliminate stress completely, people can learn to manage it by participating in different kinds of stress management interventions. This study examined the effectiveness of stress management interventions on neuroendocrine responses in stressed students and health professionals, by measuring hair cortisol in comparison to salivary cortisol. MAIN METHODS: Salivary and hair cortisol measurements were performed in 37 subjects (31women, 6 men; mean age 34.0±10.6) who attended to a Coping Stress and Quality of Care Program at the University of Buenos Aires. Cortisol was measured at the beginning and at the end of the program. The State-Trait Anxiety Inventory STAI was used to evaluate state and trait anxiety. KEY FINDINGS: In subjects who completed the program, no differences were observed in salivary cortisol levels between the first and the last session. However, in these subjects, hair cortisol obtained in the last session was significantly lower than hair cortisol in the first session. SIGNIFICANCE: Hair cortisol appears to be a better biomarker than salivary cortisol for evaluation of the effectiveness of a stress reduction program and it seems to be a better indicator of stress system dysregulation as well.

Psychological and physiological response of students to different types of stress management programs.

PURPOSE: To design, implement, and examine the psychoneuroendocrine responses of three different types of stress management programs. DESIGN: Randomly assigned. A pre/post experimental design comparing variables between three different programs and a control group. The first program included training in deep breathing, relaxation response, meditation, and guided imagery techniques (RRGI). The second program included training in cognitive behavioral techniques (CB). The third program included both RRGI and CB (RRGICB). SETTING: The study was conducted at Buenos Aires University. SUBJECTS: Participants (N  = 52) were undergraduate students. MEASURES: Anxiety, anger, hopelessness, neuroticism, respiration rate, and salivary cortisol levels were assessed. ANALYSIS: Wilcoxon signed rank test was used to investigate differences in pre and post variables. RESULTS: Subjects in the RRGI group showed significantly lower levels of anxiety (p < .011), anger (p < .012), neuroticism (p < .01), respiratory rate (p < .002), hopelessness (p < .01), and salivary cortisol (p < .002) after the treatment. Subjects in the CB group showed significantly lower levels of anxiety (p < .018), anger (p < .037), and neuroticism (p < .03) after the treatment. Subjects in the RRGICB group showed significantly lower levels of anxiety (p < .001), anger (p < .001), neuroticism (p < .008), hopelessness (p < .01), respiratory rate (p < .001), and salivary cortisol (p < .002) after the treatment. Subjects in the control group showed only one variable modification, a significant increase in cortisol levels (p < .004). CONCLUSIONS: The combination of deep breathing, relaxation response, meditation, and guided imagery techniques with CB seems to be effective at helping people to deal with stress.

Determination of aristolochic acids by capillary electrophoresis.

A method for the separation and quantification of aristolochic acids by capillary electrophoresis is described. Buffer solutions composed of sodium dihydrogen phosphate, sodium borate, and sodium dodecyl sulfate at pH 6.5-7 were found to be suitable for the separation of aristolochic acids, which can be well resolved in a few minutes. The separation and identification of six aristolochic acids contained in a commercial tincture called charrua, a traditional herbal medicine consisting of a hydroalcoholic extract of Aristolochia argentina, corroborate the usefulness of the method. The eventual toxic properties of the aristolochic acid containing charrua tincture are discussed.