Measuring student satisfaction as the first assessment of the Program of Combined Studies in Medicine, an MD/PhD-like program of the Faculty of Medicine, National Autonomous University of Mexico.

BACKGROUND: The Program of Combined Studies in Medicine (PECEM, by its acronym in Spanish) is a program for simultaneous bachelor and doctorate studies (MD/PhD) that enrolls students who show academic excellence and interest in scientific research. The initial doctoral training comprises seven six-month research stays in different laboratories or clinical or computer areas with different high-quality scientific advisors who provide students with a unique experience for their scientific training. Therefore, satisfaction in this stage is decisive for students' performance and physical and psychological health. The aim of the present study was to administer a questionnaire to measure students' satisfaction with their research experience as a service-product bundle. METHODS: Students answered an online questionnaire that evaluated three dimensions: perceived quality of the advisor, skills development, and infrastructure and support. Several satisfiers were also evaluated: recommendation of the advisor to peers, fulfillment of student expectations and satisfaction with the program. Correlations were calculated using Fisher's exact test. The significance was set at p < 0.05. RESULTS: The high quality of the advisor, skills development and guidance during the stay were satisfiers correlated to the students' recommendation of their advisors to their peers and to the fulfillment of the students' scientific expectations. Conversely, skills development and infrastructure and support were satisfiers for a good to excellent experience as a PECEM student. A lack of direct interaction with the advisor's workgroup was related to dissatisfaction. CONCLUSIONS: The nontangible products of the service, such as a positive interaction between the student, the advisor and the advisor's workgroup as well as support obtained during the research stay, were satisfiers. These data indicate that promoting a fruitful bond between the student and advisor is a priority to ensure the quality of our innovative MD/PhD program.

Elevated Levels of Cytotoxicity, Cytokines, and Anti-SARS-CoV-2 Antibodies in Mild Cases of COVID-19.

Current evidence shows higher production of cytokines and antibodies against severe acute respiratory coronavirus 2 (SARS-CoV-2) in severe and critical cases of Coronavirus Disease 2019 (COVID-19) in comparison with patients with moderate or mild disease. A recent hypothesis proposes an important role of genotoxicity and cytotoxicity in the induction of the cytokine storm observed in some patients at later stages of the disease. Interestingly, in this study, we report significantly higher levels of interleukin (IL)-1ß, IL-6, MCP-1, and IL-4 cytokines in mild COVID-19 patients versus severe cases, as well as a high frequency of karyorrhexis (median [Me] = 364 vs. 20 cells) and karyolysis (Me = 266 vs. 52 cells) in the mucosal epithelial cells of both groups of patients compared with uninfected individuals. Although we observed higher levels of anti-SARS-CoV-2 IgM and IgG antibodies in COVID-19 patients, IgM antibodies were significantly higher only in mild cases, for the N and the S viral antigens. High levels of IgG antibodies were observed in both mild and severe cases. Our results showed elevated concentrations of proinflammatory and anti-inflammatory cytokines in mild cases, which may reflect an active innate immune response and could be related to the higher IgM and IgG antibody levels found in those patients. In addition, we found that SARS-CoV-2 infection induces cytotoxic damage in the oral mucosa, highlighting the importance of studying the genotoxic and cytotoxic events induced by infection and its role in the pathophysiology of COVID-19.

Seroconversion dynamic and SARS-CoV-2 seropositivity in unvaccinated population during the first and second outbreaks in Mexico.

Serosurveillance helps establish reopening guidelines and determine the immunity levels in different populations to reach herd immunity. Then, there is an urgent need to estimate seroprevalence population wide. In Mexico, information about COVID-19 cases and related deaths is scarce. Also, there is no official serosurveillance, limiting our knowledge of the impact of the SARS-CoV-2 pandemic. Here, we report the prevalence of anti-SARS-CoV-2 antibodies in 522,690 unvaccinated people from July 5th to December 31st, 2020. The overall seroprevalence was 32.8% and highest in adults aged 30-39 years (38.5%) than people under 20 years (33.0%) or older (28.9%). Moreover, in a cohort of 1655 individuals confirmed COVID-19 by PCR, we found that symptomatic people (HR = 2.56) increased seroconversion than presymptomatic. Also, we identified that the most discriminative symptoms for COVID-19 that could predict seroconversion were anosmia and ageusia (HR = 1.70), fever, myalgia/arthralgia, and cough (HR = 1.75). Finally, we found that obese people had lower seroconversion (HR = 0.53) than healthy people, but the opposite happens in diabetic people (HR = 1.39). These findings reveal that around one-third of Mexican outpatients had anti-SARS-CoV-2 antibodies before vaccination. Also, some symptoms improve empirically COVID-19 diagnosis and seroconversion. This information could help fine-tune vaccination schemes and the reopening and back-to-work algorithms.

Evagination of metacestodes of the WFU strain of Taenia crassiceps and evaluation of the impact of immune suppression of hamsters during tapeworm development.

Taeniosis-cysticercosis caused by Taenia crassiceps (Zeder, 1800) is a useful experimental model for biomedical research, in substitution of Taenia solium Linnaeus, 1758, studied during decades to develop effective vaccination, novel anti-helminthic drugs and diagnostic tools. Cysticercosis in mouse (Mus musculus Linnaeus) is achieved by the larval subculturing of the Wake Forest University (WFU) strain of T. crassiceps. Golden hamster, Mesocricetus auratus (Waterhouse), has been shown to be the most suitable host for adult forms of parasite in experimental taeniosis. Metacestodes of T. crassiceps WFU multiply by budding without restrictions once inoculated into the mouse, while the number of tapeworms developed from these larvae in hamsters remains highly variable. Three objectives have been proposed to improve the infection of T. crassiceps WFU in hamsters: (1) to re-evaluate the need of immune suppression; (2) to investigate the advantage of infecting hamsters with metacestodes with in vitro protruded scolices; and (3) to compare a number of tapeworms developed from metacestodes subcultured in hamsters against those proliferated in mice. Our results demonstrated that when the evagination of murine metacestodes was high, the number of T. crassiceps WFU adults obtained from hamsters was also high. Immunosuppressive treatment remains relevant for this experimental rodent model. The hamster-to-hamster cysticercosis-taeniosis by T. crassiceps overcame the mouse-to-hamster model in the yield of adult specimens. In vitro scolex evagination and metacestode asexual proliferation in hamsters place this rodent model by T. crassiceps WFU as the most affordable experimental models with taeniids.

Molecular diagnosis of human papillomavirus in the development of cervical cancer.

Cervical cancer (CC) is a major public health problem in developing countries and its most significant etiological risk factor is infection by the human papillomavirus (HPV). The main approach to date for the prevention of CC has been through screening programs, using the cervical smear (PAP test) to detect precursory lesions. The sensitivity and specificity of the PAP smear depend on the skills of the observer to recognize and classify a variety of cellular abnormalities. The development of early diagnoses to detect HPV infection has been a problem as cytology and colposcopy identify the lesion at an advanced stage. Therefore, molecular approaches have become more successful for early CC diagnosis. These molecular techniques recognize HPV DNA sequences by DNA hybridization, PCR-RFLP, hybrid capture and reverse line blot systems. Unfortunately, these systems cannot determine whether the HPV infection is active, latent or persistent. Thus, immunological techniques such as Western blot and ELISA have been designed to follow the immune response against the virus, and they can also be used to identify the stage of the infection. Several companies have developed, manufactured and merchandised gene-based testing systems for the screening, monitoring and diagnosis of HPV. Our review and comments focus on the critical analysis of existing products and their use in clinical practice as well as on immunological systems used mainly in research, but that may be applied in large population screening programs.

Performance of ELISA and Western blot to detect antibodies against HSV-2 using dried blood spots.

BACKGROUND AND AIMS: Herpes simplex virus type 2 (HSV-2) is a sexually transmitted agent and is detected worldwide. HSV-2 is the main cause of genital ulcers and is diagnosed mainly with serological tests. The objective of current study was to evaluate the use of DBS samples to detect HSV-2 antibodies using commercial ELISA and Western blot tests. MATERIALS AND METHODS: IgG-G2 ELISA (Human® Diagnostics, Germany) and Western blot IgG/IgM (EUROLINE-WB, Euroimmun® Germany) tests were modified to use DBS samples. Samples were processed by both methods to determine ELISA cutoff points using ROC curves. ELISA was performed with 100µl and the Western blot with 200µl of eluted DBS. A 1:5 dilution was used and the incubation times were increased for the Western blot. RESULTS: 908 DBS samples were processed and the following cutoff points were determined: negative (0-3.79), undetermined (3.8-4.6) and positive (≥4.61), with sensitivity and specificity close to 95%. CONCLUSION: Modifications of the cutoff points of the ELISA test were obtained with technical adjustments done to detect HSV-2 antibodies by ELISA and Western blot using DBS samples.

College women, HPV genotyping and sexual behavior before HPV vaccination: Results from samples stored for a long time.

HPV is the sexually transmitted agent most common among young people, like college students. The aim of study was to associate sexual behavior characteristics of women with HPV, detected in genital samples taken before the introduction of the HPV vaccine. Female students during 2001-2005 donated genital samples and the samples were re-analyzed in 2013 for HPV genotyping by RT-PCR. The frozen storage of the students' genital samples allowed the detection of HPV DNA and its genotyping after years of sample collection. HPV prevalence was 22%, HPV16 3.9%, and HPV18 1.1%. Age, multiple sexual partners and the partner's age at first sexual intercourse were significantly associated to HPV. Students with ≥ 3 sexual partners and who did not use condom had 12.8 higher odds of being HPV positive. These results made possible the analysis of HPV prevalence changes, before HPV vaccine introduction.

Molecular diagnosis of human papillomavirus in the development of cervical cancer / Diagnóstico molecular del virus del papiloma humano en el desarrollo del cáncer cervical

Cervical cancer (CC) is a major public health problem in developing countries and its most significant etiological risk factor is infection by the human papillomavirus (HPV). The main approach to date for the prevention of CC has been through screening programs, using the cervical smear (PAP test) to detect precursory lesions. The sensitivity and specificity of the PAP smear depend on the skills of the observer to recognize and classify a variety of cellular abnormalities. The development of early diagnoses to detect HPV infection has been a problem as cytology and colposcopy identify the lesion at an advanced stage. Therefore, molecular approaches have become more successful for early CC diagnosis. These molecular techniques recognize HPV DNA sequences by DNA hybridization, PCR-RFLP, hybrid capture and reverse line blot systems. Unfortunately, these systems cannot determine whether the HPV infection is active, latent or persistent. Thus, immunological techniques such as Western blot and ELISA have been designed to follow the immune response against the virus, and they can also be used to identify the stage of the infection. Several companies have developed, manufactured and merchandised gene-based testing systems for the screening, monitoring and diagnosis of HPV. Our review and comments focus on the critical analysis of existing products and their use in clinical practice as well as on immunological systems used mainly in research, but that may be applied in large population screening programs.

El cáncer cervical (CC) es el mayor problema de salud pública en países en vías de desarrollo, al ser la infección por el virus del papiloma humano (HPV) el factor etiológico más importante de esta enfermedad. Actualmente, el principal acercamiento para la prevención del CC ha sido a través de programas de detección oportuna del cáncer, lo cual se ha realizado a través del estudio citológico del Papanicolaou (Pap) para la detección de lesiones precursoras. Sin embargo, la sensibilidad y especificidad de la prueba de Pap depende de la destreza del observador en el reconocimiento y clasificación de diferentes anormalidades en las células. El desarrollo de sistemas de diagnóstico temprano para la detección de la infección por HPV ha sido problemático debido a que tanto la citología como la colposcopía identifican la lesión cervical en estadios muy avanzados. De esta forma, la aplicación de las pruebas moleculares ha sido exitosa en el diagnóstico temprano del CC. Estas técnicas moleculares se basan en el reconocimiento de secuencias de ADN de HPV por medio de hibridación del ADN, PCR-RFLP, captura de híbridos (hybrid capture) y el sistema de línea reversa (reverse line blot). Desafortunadamente, estos sistemas no pueden identificar si se trata de una infección activa, latente o persistente. Por esta razón, las técnicas inmunológicas como el Western blot y el ELISA han sido diseñadas para realizar el seguimiento de la respuesta inmune contra el virus. Por ello, aquí se hace una revisión de las técnicas moleculares utilizadas para detectar el HPV, como factor de riesgo del CC, así como las técnicas inmunológicas desarrolladas para el seguimiento de la respuesta inmune contra este virus. Existen diferentes compañías que han desarrollado, manufacturado y comercializado pruebas diagnósticas basadas en identificación de genes para el tamizaje, monitoreo y diagnóstico de HPV. Nuestra revisión se enfoca en el análisis de productos que existen en el mercado, así como en los sistemas inmunológicos usados en investigación y en programas de tamizaje de extensas poblaciones.