Risk factors for acute kidney injury in patients hospitalized with COVID-19 / Fatores de risco para lesão renal aguda em pacientes hospitalizados com COVID-19

Abstract Introduction: Acute kidney injury (AKI) occurs frequently in COVID-19 patients and is associated with greater morbidity and mortality. Knowing the risks of AKI allows for identification, prevention, and timely treatment. This study aimed to identify the risk factors associated with AKI in hospitalized patients. Methods: A descriptive, retrospective, cross-sectional, and analytical component study of adult patients hospitalized with COVID-19 from March 1 to December 31, 2020 was carried out. AKI was defined by the creatinine criteria of the KDIGO-AKI guidelines. Information, regarding risk factors, was obtained from electronic medical records. Results: Out of the 934 patients, 42.93% developed AKI, 60.59% KDIGO-1, and 9.9% required renal replacement therapy. Patients with AKI had longer hospital stay, higher mortality, and required more intensive care unit (ICU) admission, mechanical ventilation, and vasopressor support. Multivariate analysis showed that age (OR 1.03; 95% CI 1.02-1.04), male sex (OR 2.13; 95% CI 1.49-3.04), diabetes mellitus (DM) (OR 1.55; 95% CI 1.04-2.32), chronic kidney disease (CKD) (OR 2.07; 95% CI 1.06-4.04), C-reactive protein (CRP) (OR 1.02; 95% CI 1.00-1.03), ICU admission (OR 1.81; 95% CI 1.04-3.16), and vasopressor support (OR 7.46; 95% CI 3.34-16.64) were risk factors for AKI, and that bicarbonate (OR 0.89; 95% CI 0.84-0.94) and partial pressure arterial oxygen/inspired oxygen fraction index (OR 0.99; 95% CI 0.98-0.99) could be protective factors. Conclusions: A high frequency of AKI was documented in COVID-19 patients, with several predictors: age, male sex, DM, CKD, CRP, ICU admission, and vasopressor support. AKI occurred more frequently in patients with higher disease severity and was associated with higher mortality and worse outcomes.

RESUMO Introdução: Lesão renal aguda (LRA) ocorre frequentemente em pacientes com COVID-19 e associa-se a maior morbidade e mortalidade. Conhecer riscos da LRA permite a identificação, prevenção e tratamento oportuno. Este estudo teve como objetivo identificar fatores de risco associados à LRA em pacientes hospitalizados. Métodos: Realizou-se estudo descritivo, retrospectivo, transversal e de componente analítico de pacientes adultos hospitalizados com COVID-19 de 1º de março a 31 de dezembro, 2020. Definiu-se a LRA pelos critérios de creatinina das diretrizes KDIGO-LRA. Informações sobre fatores de risco foram obtidas de prontuários eletrônicos. Resultados: Dos 934 pacientes, 42,93% desenvolveram LRA, 60,59% KDIGO-1 e 9,9% necessitaram de terapia renal substitutiva. Pacientes com LRA apresentaram maior tempo de internação, maior mortalidade e necessitaram de mais internações em UTIs, ventilação mecânica e suporte vasopressor. A análise multivariada mostrou que idade (OR 1,03; IC 95% 1,02-1,04), sexo masculino (OR 2,13; IC 95% 1,49-3,04), diabetes mellitus (DM) (OR 1,55; IC 95% 1,04-2,32), doença renal crônica (DRC) (OR 2,07; IC 95% 1,06-4,04), proteína C reativa (PCR) (OR 1,02; IC 95% 1,00-1,03), admissão em UTI (OR 1,81; IC 95% 1,04-3,16) e suporte vasopressor (OR 7,46; IC 95% 3,34-16,64) foram fatores de risco para LRA, e que bicarbonato (OR 0,89; IC 95% 0,84-0,94) e índice de pressão parcial de oxigênio arterial/fração inspirada de oxigênio (OR 0,99; IC 95% 0,98-0,99) poderiam ser fatores de proteção. Conclusões: Documentou-se alta frequência de LRA em pacientes com COVID-19, com diversos preditores: idade, sexo masculino, DM, DRC, PCR, admissão em UTI e suporte vasopressor. LRA ocorreu mais frequentemente em pacientes com maior gravidade da doença e associou-se a maior mortalidade e piores desfechos.

Risk factors for acute kidney injury in patients hospitalized with COVID-19.

INTRODUCTION: Acute kidney injury (AKI) occurs frequently in COVID-19 patients and is associated with greater morbidity and mortality. Knowing the risks of AKI allows for identification, prevention, and timely treatment. This study aimed to identify the risk factors associated with AKI in hospitalized patients. METHODS: A descriptive, retrospective, cross-sectional, and analytical component study of adult patients hospitalized with COVID-19 from March 1 to December 31, 2020 was carried out. AKI was defined by the creatinine criteria of the KDIGO-AKI guidelines. Information, regarding risk factors, was obtained from electronic medical records. RESULTS: Out of the 934 patients, 42.93% developed AKI, 60.59% KDIGO-1, and 9.9% required renal replacement therapy. Patients with AKI had longer hospital stay, higher mortality, and required more intensive care unit (ICU) admission, mechanical ventilation, and vasopressor support. Multivariate analysis showed that age (OR 1.03; 95% CI 1.02-1.04), male sex (OR 2.13; 95% CI 1.49-3.04), diabetes mellitus (DM) (OR 1.55; 95% CI 1.04-2.32), chronic kidney disease (CKD) (OR 2.07; 95% CI 1.06-4.04), C-reactive protein (CRP) (OR 1.02; 95% CI 1.00-1.03), ICU admission (OR 1.81; 95% CI 1.04-3.16), and vasopressor support (OR 7.46; 95% CI 3.34-16.64) were risk factors for AKI, and that bicarbonate (OR 0.89; 95% CI 0.84-0.94) and partial pressure arterial oxygen/inspired oxygen fraction index (OR 0.99; 95% CI 0.98-0.99) could be protective factors. CONCLUSIONS: A high frequency of AKI was documented in COVID-19 patients, with several predictors: age, male sex, DM, CKD, CRP, ICU admission, and vasopressor support. AKI occurred more frequently in patients with higher disease severity and was associated with higher mortality and worse outcomes.

Utility of a clinical risk scale to predict the requirement of advanced airway management in patients with a diagnosis of deep neck abscess.

OBJECTIVES: To analyze the clinical utility of a clinical risk scale to predict the need for advanced airway management in patients with deep neck abscess. METHODS: Observational, analytical, cross-sectional study. Patients over 18 years old, both genders, with surgical management of a deep neck abscess, between January 1st, 2015 to December 31th, 2021, who were applied the clinical risk scale (https://7-414-5-19.shinyapps.io/ClinicalRiskScore/). The sensitivity, specificity, and predictive values of the scale were calculated based on the identified clinical outcomes. A p<0.05 was considered significant. RESULTS: A sample of 213 patients was obtained, 121 (56.8%) men, of whom 50 (23.5%) required advanced airway management. Dyspnea was the variable with the most statistical weight in our study, (p=0.001) as well as the multiple spaces involvement, (p=0.001) the presence of air corpuscles, (p=0.001) compromise of the retropharyngeal space (p=0.001) and age greater than 55 years (p=0.001). Taking these data into account, were found for the clinical risk scale a sensitivity of 97% and a specificity of 65% (p=0.001, 95% CI 0.856-0.984). CONCLUSIONS: The clinical risk scale developed to predict advanced airway management in patients with a diagnosis of deep neck abscess may be applicable in our environment with high sensitivity and specificity. LEVEL OF EVIDENCE: IV.

Utility of a clinical risk scale to predict the requirement of advanced airway management in patients with a diagnosis of deep neck abscess,

Abstract Objectives To analyze the clinical utility of a clinical risk scale to predict the need for advanced airway management in patients with deep neck abscess. Methods Observational, analytical, cross-sectional study. Patients over 18 years old, both genders, with surgical management of a deep neck abscess, between January 1st, 2015 to December 31th, 2021, who were applied the clinical risk scale (https://7-414-5-19.shinyapps.io/ClinicalRiskScore/). The sensitivity, specificity, and predictive values of the scale were calculated based on the identified clinical outcomes. A p < 0.05 was considered significant. Results A sample of 213 patients was obtained, 121 (56.8%) men, of whom 50 (23.5%) required advanced airway management. Dyspnea was the variable with the most statistical weight in our study, (p = 0.001) as well as the multiple spaces involvement, (p = 0.001) the presence of air corpuscles, (p = 0.001) compromise of the retropharyngeal space (p = 0.001) and age greater than 55 years (p = 0.001). Taking these data into account, were found for the clinical risk scale a sensitivity of 97% and a specificity of 65% (p = 0.001, 95% CI 0.856-0.984). Conclusions The clinical risk scale developed to predict advanced airway management in patients with a diagnosis of deep neck abscess may be applicable in our environment with high sensitivity and specificity. Level of evidence: IV.

Local protection bubbles: an interpretation of the slowdown in the spread of coronavirus in the city of São Paulo, Brazil, in July 2020.

After four months of fighting the pandemic, the city of São Paulo, Brazil, entered a phase of relaxed social distancing measures in July 2020. Simultaneously, there was a decline in the social distancing rate and a reduction in the number of cases, fatalities, and hospital bed occupancy. To understand the pandemic dynamics in the city of São Paulo, we developed a multi-agent simulation model. Surprisingly, the counter-intuitive results of the model followed the city's reality. We argue that this phenomenon could be attributed to local bubbles of protection that emerged in the absence of contagion networks. These bubbles reduced the transmission rate of the virus, causing short and temporary reductions in the epidemic curve - but manifested as an unstable equilibrium. Our hypothesis aligns with the virus spread dynamics observed thus far, without the need for ad hoc assumptions regarding the natural thresholds of collective immunity or the heterogeneity of the population's transmission rate, which may lead to erroneous predictions. Our model was designed to be user-friendly and does not require any scientific or programming expertise to generate outcomes on virus transmission in a given location. Furthermore, as an input to start our simulation model, we developed the COVID-19 Protection Index as an alternative to the Human Development Index, which measures a given territory vulnerability to the coronavirus and includes characteristics of the health system and socioeconomic development, as well as the infrastructure of the city of São Paulo.

Local protection bubbles: an interpretation of the slowdown in the spread of coronavirus in the city of São Paulo, Brazil, in July 2020 / Bolhas de proteção locais: uma interpretação da diminuição da velocidade de disseminação do coronavírus na cidade de São Paulo, Brasil, em julho de 2020 / Burbujas de protección locales: una interpretación de la reducción de la velocidad de propagación del coronavirus en la ciudad de São Paulo, Brasil, en julio de 2020

Abstract: After four months of fighting the pandemic, the city of São Paulo, Brazil, entered a phase of relaxed social distancing measures in July 2020. Simultaneously, there was a decline in the social distancing rate and a reduction in the number of cases, fatalities, and hospital bed occupancy. To understand the pandemic dynamics in the city of São Paulo, we developed a multi-agent simulation model. Surprisingly, the counter-intuitive results of the model followed the city's reality. We argue that this phenomenon could be attributed to local bubbles of protection that emerged in the absence of contagion networks. These bubbles reduced the transmission rate of the virus, causing short and temporary reductions in the epidemic curve - but manifested as an unstable equilibrium. Our hypothesis aligns with the virus spread dynamics observed thus far, without the need for ad hoc assumptions regarding the natural thresholds of collective immunity or the heterogeneity of the population's transmission rate, which may lead to erroneous predictions. Our model was designed to be user-friendly and does not require any scientific or programming expertise to generate outcomes on virus transmission in a given location. Furthermore, as an input to start our simulation model, we developed the COVID-19 Protection Index as an alternative to the Human Development Index, which measures a given territory vulnerability to the coronavirus and includes characteristics of the health system and socioeconomic development, as well as the infrastructure of the city of São Paulo.

Resumo: Após quatro meses lutando contra a pandemia, a cidade de São Paulo, Brasil, entrou em uma fase de flexibilização das medidas de distanciamento social em julho de 2020. Simultaneamente, houve queda na taxa de distanciamento social e redução no número de casos, mortes e ocupação de leitos hospitalares. Um modelo de simulação multiagente foi desenvolvido para entender a dinâmica da pandemia na cidade de São Paulo. Ao contrário do esperado, os resultados contraintuitivos do modelo acompanharam a realidade da cidade. Argumentamos que este fenômeno pode ser atribuído às bolhas locais de proteção que surgiram na ausência de redes de contágio. Estas bolhas reduziram a taxa de transmissão do vírus, causando reduções curtas e temporárias na curva epidêmica - mas se manifestaram como um equilíbrio instável. Nossa hipótese está alinhada com a dinâmica da propagação do vírus observada até o momento, sem a necessidade de suposições ad hoc sobre limiares de imunidade coletiva natural ou heterogeneidade da taxa de transmissão da população, o que pode levar a previsões errôneas. Nosso modelo foi projetado para ser fácil de usar e não requer nenhum conhecimento científico ou de programação para gerar resultados sobre a transmissão do vírus em um determinado local. Além disso, como insumo para iniciar nosso modelo de simulação, desenvolvemos o Índice de Proteção contra a COVID-19 como alternativa ao Índice de Desenvolvimento Humano, que mede a vulnerabilidade de um determinado território ao coronavírus e inclui características do sistema de saúde e do desenvolvimento socioeconômico, além da infraestrutura da cidade de São Paulo.

Resumen: Tras cuatro meses luchando contra la pandemia, la ciudad de São Paulo, Brasil, empezó una fase de flexibilización de las medidas de alejamiento social en julio de 2020. A la vez, hubo una reducción en la tasa de alejamiento social y en el número de casos, muertes y ocupación de camas en los hospitales. Se desarrolló un modelo de simulación multiagente para entender la dinámica de la pandemia en la ciudad de São Paulo. Diferente de lo esperado, los resultados contradictorios del modelo reflejaron la realidad de la ciudad. Sostenemos que se puede atribuir este fenómeno a las burbujas locales de protección que surgieron durante la ausencia de redes de contagio. Estas burbujas redujeron la tasa de transmisión del virus, reduciendo de forma corta y temporal la curva epidémica -pero se manifestaron como un equilibrio inestable. Nuestra hipótesis se alinea con la dinámica de la propagación del virus observada hasta el momento, sin la necesidad de suposiciones ad hoc sobre umbrales de inmunidad colectiva natural o heterogeneidad de la tasa de transmisión de la población, lo que puede provocar previsiones equivocadas. Nuestro modelo se proyectó para ser fácil de usar y no necesita ningún conocimiento científico o de programación para generar resultados sobre la transmisión del virus en un determinado local. Además, como insumo para iniciar nuestro modelo de simulación, desarrollamos el Índice de Protección contra la COVID-19 como una alternativa al Índice de Desarrollo Humano, que mide la vulnerabilidad de un determinado territorio al coronavirus e incluye características del sistema de salud y del desarrollo socioeconómico, además de la infraestructura de la ciudad de São Paulo.

Retroperitoneal Teratoma in a Transplanted Patient: Case Report and Review.

BACKGROUND: The development of de novo neoplasms in solid organ transplantation is multifactorial. In addition to common factors in the general population, there are specific factors of the disease related or not to chronic renal failure and factors inherent to the transplant itself such as immunosuppression. OBJECTIVE: The aim of this study is to describe the case of a kidney recipient with a retroperitoneal teratoma, his satisfactory treatment, and a brief literature review. METHODS: The case of 59-year-old male patient who received a living donor transplant in 2011, with conventional immunosuppression, graft protocol biopsy per year reported as normal, and follow-up without eventualities is described. The patient's symptoms began in December 2020 with abdominal pain resistant to analgesics, asthenia, and adynamic. Contrast tomography showed a retroperitoneal tumor 25.8 × 16.9 × 19 cm; tumor markers: alpha fetoprotein, 2.16 ng/mL; cancer antigen 19-9, 524.5 UI/ml; and carcinoembryonic antigen, 67.53 ng/mL. Resection of a 25 × 25 × 20 cm retroperitoneal tumor between the vena cava and aorta with 2 L of mucus content was performed. The patient was discharged from the hospital on the second day, with uresis 1 mL/kg/h, and at one month with adequate renal function, and 0.94 mg/dL of serum creatinine. A definitive histologic report was compatible with retroperitoneal mature teratoma. CONCLUSION: Primary retroperitoneal mature teratoma is rarely evidenced in adult patients, usually asymptomatic, and the definitive diagnosis always is established after histologic evaluation. Surgical resection is the main treatment with the complete removal of the tumor and long-term monitoring is needed because of the risk of malignancy.

Priapism in a patient on hemodialysis and with COVID-19. Case report / Priapismo en paciente en diálisis y con COVID-19. Reporte de caso

Abstract Introduction: Priapism is rare in dialysis patients. It is associated with several risk factors inherent to therapy and kidney disease. This condition has been reported in severe COVID-19 cases, probably caused by coagulopathy secondary to the infection. However, it has not been reported in patients with mild COVID-19. Case presentation: A 65-year-old patient on hemodialysis and with mild COVID-19 presented with a 30-hour painful penile erection. Physical examination revealed an erection, but no other significant findings were observed. Based on the clinical history, physical examination and laboratory test results, the patient was diagnosed with ischemic priapism. Corpora cavernosa drainage was performed and two injections of epinephrine (each with a dose of 2mL of epinephrine solution 1/100 000) were administered, achieving complete resolution of the symptoms. Conclusions: At the time of writing this case report, there is no information available on cases of priapism in patients with mild manifestations of COVID-19, nor is it clear how the risk of thrombosis should be assessed in this group of patients. From a pathophysiological point of view, factors related to dialysis and kidney disease could have predisposed this patient to priapism, although the role of SARS-CoV-2 infection is uncertain. Therefore, further studies are required to confirm or rule out the association between COVID-19 and priapism in dialysis patients.

Resumen Introducción. El priapismo es una condición infrecuente en pacientes en diálisis que se puede presentar por factores inherentes a esta terapia y a la enfermedad renal. Por otra parte, es una entidad que se ha reportado en pacientes con síntomas severos de COVID-19 y se ha asociado a coagulopatía secundaria a la infección, pero de la que no hay registro en casos leves de esta enfermedad. Presentación de caso. Paciente masculino de 65 años en hemodiálisis y con infección por SARS-CoV-2 con síntomas leves, quien consultó al servicio de urgencias de un hospital de cuarto nivel por erección peneana dolorosa de 30 horas de evolución. Al examen físico se evidenció la erección, sin otros hallazgos relevantes. Con base en la historia clínica, el examen físico y los resultados de laboratorio, se diagnosticó priapismo isquémico y se realizó drenaje de senos cavernosos y aplicación de dos inyecciones de epinefrina (cada una con una dosis de 2mL de solución de epinefrina 1/100 000), lográndose resolución completa de la condición. Conclusiones. Hasta el momento de la elaboración del presente reporte de caso no hay información disponible de casos de priapismo en pacientes con manifestaciones leves de COVID-19, y tampoco hay claridad de cómo se debe evaluar el riesgo de trombosis en este grupo de pacientes. Desde el punto de vista fisiopatológico, factores relacionados con la diálisis y la enfermedad renal pudieron predisponer a este paciente al priapismo, aunque no es claro el rol de la infección por SARS-CoV-2. Por tanto, se requieren estudios que permitan confirmar o descartar la asociación entre COVID-19 y priapismo en pacientes en diálisis.

Púrpura de Schönlein-Henoch con compromiso abdominal, descripción de un caso y revisión de la literatura / Henoch-Schönlein Purpura with abdominal involvement. Case report and a review of the literature

La púrpura de Schönlein-Henoch es la vasculitis de pequeños vasos más frecuente en la infancia. Se manifiesta principalmente por una púrpura palpable, artritis, dolor abdominal y compromiso renal. El compromiso gastrointestinal es muy variable, siendo su manifestación más frecuente el dolor abdominal, con diferentes grados de severidad. Para su manejo se han utilizado desde analgésicos comunes hasta inmunosupresores. Se presenta el caso de un niño que consulta por intenso dolor abdominal, por lo que es llevado a cirugía, luego presenta las típicas lesiones en piel. El dolor se intensifica llegando a comprometer la ingesta y disminuir su peso. El manejo con diferentes analgésicos y corticoides, incluso a dosis altas, no logró resultados, por lo que se utiliza inmunoglobulina G humana en dosis de 1 g/kg/día, por dos días, por vía intravenosa, con rápida y sostenida resolución del dolor, pudiendo el paciente volver a comer.

Henoch-Schönlein purpura (PSH) is the most common small blood vessels vasculitis of childhood. It is characterized by palpable purpura, arthritis, abdominal pain and renal involvement. Gastrointestinal manifestations are highly variable; its most frequent is abdominal pain with varying degrees of severity. The management is supportive and with analgesics and immunosuppressive agents. We present a child who developed severe abdominal pain, so much that he was underwent surgery. After that, He presented the typical skin lesions: palpable purpura. His abdominal pain intensified, his food intake decreased and then his weight decreased progressively. The management failed with different analgesics and corticosteroids even at high doses. Then we administered intravenous gammaglobulin 1 gr/kg/day for two days with rapid and sustained resolution of pain and improvement of food intake. Although Henoch-Schönlein purpura is generally a benign and rapid recovery condition, some cases like the one described, show that some patients need more individualized handling, leaving so much to investigate and learn from this disease.

Identification and characterization of the Plasmodium vivax thrombospondin-related apical merozoite protein.

BACKGROUND: Malaria caused by Plasmodium vivax is a major public health problem worldwide that affects 70-80 million people in the Middle East, Asia, Western Pacific, South America and the Caribbean. Despite its epidemiological importance, few antigens from this parasite species have been characterized to date compared to Plasmodium falciparum, due in part to the difficulties of maintaining an in vitro culture of P. vivax. This study describes the identification of the P. falciparum thrombospondin-related apical merozoite protein homologue in P. vivax (PvTRAMP) and examines its potential to be further evaluated as vaccine candidate. METHODS: The gene encoding PvTRAMP was identified through an extensive search of the databases hosting the genome sequence of P. vivax. Genes adjacent to pvtramp were identified in silico to determine the degree of similarity between the protein sequences encoded by equivalent chromosomic fragments in P. falciparum and Plasmodium knowlesi. The pvtramp gene was amplified from cDNA of P. vivax schizont stages, cloned and expressed in Escherichia coli. Anti-PvTRAMP antisera was obtained by inoculating rabbits with PvTRAMP B cell epitopes produced as synthetic peptides in order to assess its recognition in parasite lysates by Western blot and in intact parasites by indirect immunofluorescence. The recognition of recombinant PvTRAMP by sera from P. vivax-infected individuals living in endemic areas was also assessed by ELISA. RESULTS: The PfTRAMP homologue in P. vivax, here denoted as PvTRAMP, is a 340-amino-acid long antigen encoded by a single exon that could have a potential role in cytoadherence, as indicated by the presence of a thrombospondin structural homology repeat (TSR) domain. According to its transcription and expression profile, PvTRAMP is initially located at the parasite's apical end and later on the parasite surface. Recombinant PvTRAMP is recognized by sera from infected patients, therefore, indicating that it is targeted by the immune system during a natural infection with P. vivax. CONCLUSIONS: The results of this work support conducting further studies with PvTRAMP to evaluate its immunogenicity and protection-inducing ability in the Aotus animal model.

Characterization and antigenicity of the promising vaccine candidate Plasmodium vivax 34kDa rhoptry antigen (Pv34).

This study describes the identification of the Plasmodium vivax rhoptry antigen Pv34 whose sequence was obtained based on homology comparison with the Plasmodium falciparum Pf34. The pv34 gene product was characterized by molecular biology and immunological techniques. Additionally, association of Pv34 to detergent-resistant microdomains (DRMs), expression in late blood-stage parasites and recognition of recombinant Pv34 (rPv34) by sera from P. vivax-infected Aotus monkeys and patients was assessed. Lymphoproliferation and cytokine secretion was also evaluated in individuals living in malaria endemic areas. Altogether, the data support carrying out further studies to assess the immunogenicity and protection-inducing ability of rPv34 as component of a multi-antigenic, multi-stage vaccine against vivax malaria.

The Plasmodium vivax Pv41 surface protein: identification and characterization.

Recently, Plasmodium vivax has been related to nearly 81% of malaria cases reported in Central America and the Mediterranean. Due to the difficulty of culturing this parasite species in vitro, most studies on P. vivax have focused on the identification of new antigens by homology comparison with P. falciparum vaccine candidate proteins. In this study, we have identified and characterized a Pf41 homologue in P. vivax, hence named Pv41, by following such approach and using web-available bioinformatics databases, molecular techniques and immunochemistry assays. Pv41 protein is a 384-amino-acid-long antigen encoded by a single exon that exhibits two s48/45 domains characteristic of gametocyte surface proteins. We have also demonstrated Pv41 transcription and expression during late intra-erythrocytic parasite stages and defined its subcellular localization on the parasite surface.

Characterisation of the Plasmodium vivax Pv38 antigen.

This study describes the identification and characterisation of Pv38, based on the available genomic sequence of Plasmodium vivax and previous studies done with its Plasmodium falciparum homologue: Pf38. Pv38 is a 355 amino acid long peptide encoded by a single exon gene, for which orthologous genes have been identified in other Plasmodium species by bioinformatic approaches. As for Pf38, Pv38 was found to contain a s48/45 domain which is usually found in proteins displayed on gametocytes surface. The association of Pv38 with detergent-resistant membranes (DRMs), its expression in mature blood stages of the parasite (mainly schizonts) and the detection of its recombinant protein by sera from Aotus monkeys previously exposed to the parasite, were here assessed to further characterise this new antigen.

Identifying and characterising the Plasmodium falciparum RhopH3 Plasmodium vivax homologue.

Four Plasmodium species cause malaria in humans, Plasmodium falciparum being the most widely studied to date. All Plasmodium species have paired club-shaped organelles towards their apical extreme named rhoptries that contain many lipids and proteins which are released during target cell invasion. P. falciparum RhopH3 is a rhoptry protein triggering important immune responses in patients from endemic regions. It has also been shown that anti-RhopH3 antibodies inhibit in vitro invasion of erythrocytes. Recent immunisation studies in mice with the Plasmodium yoelii and Plasmodium berghei RhopH3 P. falciparum homologue proteins found that they are able to induce protection in murine models. This study described identifying and characterising RhopH3 protein in Plasmodium vivax; it is encoded by a seven exon gene and expressed during the parasite's asexual stage. PvRhopH3 has similar processing to its homologue in P. falciparum and presents a cellular immunolocalisation pattern characteristic of rhoptry proteins.

Cutaneous tuberculosis diagnosis in an inhospitable Amazonian region by means of telemedicine and molecular biology.

We report on a 13-year-old boy who displayed a chronic granulomatous inflammatory reaction of 5 years duration. The lesion was resistant to different antibiotic schemes; his routine laboratory tests and chest radiographs were normal. Teledermatologic consultation and histopathologic study of skin biopsy suggested scrofulodermal tuberculosis. Polymerase chain reaction amplification of DNA extracted from lymph node biopsy was taken as starting material for dot-blot hybridization using Mtp-40 and IS 6110 as probes for detecting either Mycobacterium tuberculosis or any mycobacteria belonging to the M tuberculosis complex, respectively. Positive results in both hybridizations were further confirmed by culturing in BACTEC MGIT 960 system. The lesion greatly diminished following isoniazid, rifampin, and ethambutol treatment. Telemedicine allowed a cutaneous tuberculosis diagnosis to be made of a patient living in a remote town located in the Amazon jungle by using molecular biology techniques.