Uso de PCR digital para definir terapéuticas específicas y seguimiento en enfermedades autoinflamatorias / Use of digital PCR to define specific therapeutics and follow-up in autoinflammatory diseases

Las enfermedades autoinflamatorias (AIDs) son un grupo heterogéneo de desórdenes monogénicos o poligénicos, con características de disregulación inmune innata y/o adaptativa, cuyo mecanismo central es la autoinflamación pero también pueden presentarse con autoinmunidad e inmunodeficiencia. En estos últimos años el desarrollo de las tecnologías de secuenciación masiva han provocado una explosión en el descubrimiento de nuevos genes responsables de AIDs monogénicas. Esto remarca la importancia de implementar este tipo de estudios para llegar a un diagnóstico definitivo sobre todo en este grupo de patologías genéticamente muy diversas donde los fenotipos clínicos se solapan. Sin embargo, dada la presencia de variantes de significación incierta (VUS), los resultados pueden no ser concluyentes planteándose la necesidad de desarrollar pruebas funcionales para determinar la patogenicidad de dichas variantes genéticas. En nuestro grupo de trabajo estamos aplicando la PCR digital en gotas (ddPCR), una técnica cuantitativa de 3era generación altamente sensible, especifica y reproducible que no necesita de curvas de calibración, para desarrollar pruebas funcionales que permitan no sólo reclasificar variantes VUS para lograr diagnósticos definitivos sino también estudiar los mecanismos responsables de las principales AIDs que permitan una estratificación de las terapéuticas especificas a aplicar y de esta manera poder contribuir al diagnóstico, tratamiento y seguimiento de nuestros pacientes en forma personalizada. (AU)

Autoinflammatory diseases (AIDs) are a heterogeneous group of monogenic or polygenic disorders, with characteristics of inborn and/or adaptive immune dysregulation, whose central mechanism is autoinflammation but may also present with autoimmunity and immunodeficiency. In recent years the development of massive sequencing technologies has led to an exponential increase in the discovery of new genes responsible for monogenic AIDs. This emphasizes the importance of the implementation of this type of studies to make a definitive diagnosis, especially in this group of genetically very diverse diseases with overlapping clinical phenotypes. However, given the presence of variants of uncertain significance (VUS), the results may not be conclusive, raising the need to develop functional tests to determine the pathogenicity of these genetic variants. In our working group we are applying droplet digital PCR (ddPCR), a highly sensitive, specific and reproducible third generation quantitative technique that does not require calibration curves, to develop functional tests that allow not only to reclassify VUS variants to achieve definitive diagnoses but also to study the mechanisms responsible for the main AIDs that allow for the stratification of specific treatments to be used and thereby contribute to the individualized diagnosis, treatment, and follow-up of our patients (AU)

The influence of Mycoplasma species on human and canine semen quality: a review / 亚洲男科学杂志(英文版)

Mycoplasma species (spp.) are bacteria that are difficult to detect. Currently, the polymerase chain reaction (PCR) is considered the most effective diagnostic tool to detect these microorganisms in both human and veterinary medicine. There are 13 known species of human Mycoplasma and 15 species of canine Mycoplasma. Owing to the difficulties in identifying the individual species of Mycoplasma, there is a lack of information regarding which species are saprophytic and which are pathogenic. The prevalence of the individual species is also unknown. In addition, in both humans and dogs, the results of some studies on the impact of Mycoplasma are conflicting. The presence of Mycoplasma spp. on the epithelium of reproductive tract is often associated with infertility, although they are also detected in healthy individuals. The occurrence of Mycoplasma spp. is more common in dogs (even 89%) than in humans (1.3%-4%). This is probably because the pH of a dog's genital is more conducive to the growth of Mycoplasma spp. than that of humans. Phylogenetically, human and canine Mycoplasma are related, and majority of them belong to the same taxonomic group. Furthermore, 40% of canine Mycoplasma spp. are placed in common clusters with those of human. This suggests that species from the same cluster can play a similar role in the canine and human reproductive tracts. This review summarizes the current state of knowledge about the impact of Mycoplasma on canine and human male fertility as well as the prospects of further development in this field.

Detección polimórfica del rs104893850 de MSX1 y rs28933373 de PAX9 en personas con agenesia dental no sindrómica / Polymorphic detection of rs104893850 of MSX1 and rs28933373 of PAX9 in people with non syndromic dental agnesia

Introducción: la agenesia dental no sindrómica (ADNS) genera efec- tos negativos en la salud oral y psicosocial de los seres humanos. El determinante genético desempeña un papel importante en su desarrollo. Objetivo: determinar la frecuencia de los polimorfismos rs104893850 de MSX1 y rs28933373 de PAX9 en pacientes de seis a 18 años con ADNS. Material y métodos: estudio transversal prolectivo en el cual se revisaron individuos de seis a 18 años sin defectos congénitos y originarios del estado de Durango. Después de haber obtenido su con- sentimiento para formar parte del estudio, se estableció el diagnóstico de ADNS a través de una inspección clínica odontológica y un examen radiográfico. Se tomó una muestra de sangre capilar para la genotipi- ficación de los polimorfismos a través de la técnica de qPCR-HRM. Resultados: de un total de 124 individuos, 77 (62%) mujeres y 47 (38%) hombres; sólo 39 presentaron ADNS. En el análisis polimórfico de rs104893850 de MSX1 y rs28933373 de PAX9 se obtuvo 94.9% y 84.6% respectivamente de homocigotos mutados. Conclusiones: se obtuvo una alta frecuencia de hipodoncia, el diente que mostró más agenesia fue el órgano dentario 18. Las mutaciones polimórficas están presentes en una alta proporción de agenesia dental (AU)

Introduction: non-syndromic dental agenesis (NSDA) generates negative oral health and psychosocial effects in humans. The genetic determinant plays an important role in its development. Objective: to determine the frequency of MSX1 rs104893850 and PAX9 rs28933373 polymorphisms in patients aged 6 to 18 years with NSDA. Material and methods: prolective cross-sectional study, in which individuals aged 6 to 18 years without congenital defects and from the city of Durango were reviewed. After obtaining their consent to be part of the study, the diagnosis of NSDA was established through a clinical dental inspection, a radiographic examination and a capillary blood sample was taken for the genotyping of the polymorphisms through the qPCR-HRM technique. Results: out of a total of 124 individuals, 77 (62%) females and 47 (38%) males; only 39 presented ADNS. In the polymorphic analysis of rs104893850 of MSX1 and rs28933373 of PAX9 we obtained 94.9% and 84.6% respectively of mutated homozygotes. Conclusions: a high frequency of hypodontia was obtained, and the tooth that presented the most agenesis was dental organ 18. Polymorphic mutations are present in a high proportion for dental agenesis (AU)

Infecciones por Chlamydia trachomatis en una unidad de cuidados intensivos neonatales / Chlamydia trachomatis infections in a neonatal intensive care unit

Las infecciones por Chlamydia trachomatis han aumentado su prevalencia, especialmente en jóvenes embarazadas. Esto adquiere relevancia en pediatría por el elevado riesgo de transmisión vertical al neonato y su potencial gravedad en el lactante. Estas infecciones requieren de un alto índice de sospecha, por cuadro clínico atípico y signos radiológicos inespecíficos. Los métodos diagnósticos convencionales presentan limitaciones para su detección. Las técnicas moleculares son las recomendadas por su elevada sensibilidad, especificidad y rapidez, lo cual permite una terapéutica adecuada y oportuna. En este estudio, desarrollado en una unidad de cuidados intensivos neonatales de un hospital de alta complejidad durante 12 años, se describieron las características de la población, su presentación clínica y evolución. La detección microbiológica se realizó por métodos moleculares. Se incluyeron 29 pacientes (p) con infección por C. trachomatis (3,9% del total de muestras enviadas),13 p con infección respiratoria y 16 p con compromiso ocular. La mediana de edad fue de 19 días al momento del diagnóstico y el 65% de las gestantes tenía <25 años. Veinticuatro p (83%) eran recién nacidos a término y 23 p (79%) previamente sanos. Nueve p (31%) presentaron fiebre al momento del ingreso y 12 (41%) eosinofilia. De los 13 p con enfermedad respiratoria, 9 (69%) consultaron por tos y 11 (85%) con hipoxemia, con requerimientos de oxígeno en 8 (61%), asistencia respiratoria mecánica en 3 (23%) y uno (16%) requirió ECMO. Los hallazgos radiológicos mostraron un patrón intersticial inespecífico. Nueve p (31%) presentaron coinfección y uno falleció asociado a influenza A (AU)

The prevalence of Chlamydia trachomatis infections has increased, especially among young pregnant women. This is of particular relevance in pediatrics due to the high risk of motherto-child transmission and the potential severity of the infection in infants. A high index of suspicion is required for these infections due to the atypical clinical features and non-specific radiological signs. The usefulness of conventional diagnostic methods is limited. Molecular techniques are recommended because of their high sensitivity, specificity, and speed, allowing for adequate and timely treatment. In this 12-year study conducted in a neonatal intensive care unit of a tertiary-care hospital, patient characteristics, clinical presentation, and outcome are described. Microbiological detection was performed using molecular methods. Twenty-nine patients with C. trachomatis infection (3.9% of the total samples submitted), of whom 13 had respiratory tract infection and 16 ocular involvement, were included. The median age at diagnosis was 19 days and 65% of the mothers were <25 years old. Twenty-four p (83%) were term newborns and 23 patients (79%) were previously healthy. On admission, 9 patients (31%) had fever and 12 (41%) had eosinophilia. Of the 13 patients with respiratory tract involvement, 9 (69%) consulted for cough and 11 (85%) had hypoxemia, requiring oxygen in 8 (61%), mechanical ventilation in 3 (23%), and ECMO in 1 (16%). Radiological findings showed a nonspecific interstitial pattern. Nine patients (31%) presented with coinfection, one of whom died due to an associated influenza A infection (AU)

Detección rápida de aneuploidías para la definición de incompatibilidad con la vida extrauterina independiente / Rapid detection of aneuploidies for definition of incompatibility with independent extrauterine life

OBJETIVO: Analizar la implementación de la prueba rápida de reacción en cadena de la polimerasa cuantitativa y fluorescente (QF-PCR) para la detección de aneuploidías. MÉTODO: Se incluyeron todas las pacientes que se realizaron una QF-PCR entre septiembre de 2017 y mayo de 2021. En todos los casos se consignaron los datos clínicos, ecográficos y de laboratorio, y se efectuó un seguimiento de quienes se realizaron además cariograma y su resultado fue normal. RESULTADOS: Se realizaron 213 procedimientos invasivos genéticos prenatales, siendo 72 para detección rápida de aneuploidía mediante QF-PCR. El promedio de edad de las madres con QF-PCR fue de 37 años y 48 pacientes (67%) tenían menos de 15 semanas de gestación. La QF-PCR demostró aneuploidía de los cromosomas 18, 13 y de triploidía en 21 de 49 casos informados como anormales. De los 22 casos sin sugerencia de alteración, 17 accedieron a proseguir el estudio con cariotipo, que resultó anormal en 6 casos. Hubo 4 casos de discordancia entre la QF-PCR y el cariotipo, que pudo afectar el manejo clínico de la gestación. En 25/72 casos (34,7%) la aneuploidía era letal. CONCLUSIONES: Considerando la necesidad de tener un diagnóstico rápido, pero también completo y que permita un consejo genético apropiado, debería integrarse la QF-PCR a un protocolo de diagnóstico que considere variables clínicas y ecográficas.

OBJECTIVE: To analyze the performance of QF-PCR test for the detection of aneuploidies. METHOD: All patients who underwent QF-PCR from September 2017 to May 2021, were included. Clinical, ultrasound and laboratory data were recorded in all cases, as well as follow-up of the cases, including those performing karyotype and the result was normal. RESULTS: 213 prenatal genetic invasive procedures were performed in the study period, 72 for rapid detection of aneuploidy by QF-PCR. 48 patients (67%) were less than 15 weeks at the time of ultrasound diagnosis. The QF-PCR test demonstrated aneuploidy of chromosomes 18, 13, and triploidy in 21/49 cases reported as abnormal. Of the cases without suggestion of alteration (22), 17 agreed to continue the study with a karyotype, which was abnormal in 6 cases. There were 4 cases of discrepancy between QF-PCR and karyotype, which could affect the clinical management of pregnancy. 25/72 cases (34. 7%) corresponded to lethal aneuploidy. CONCLUSIONS: Our results justify the use of QF-PCR. Considering the need to have a rapid diagnosis, but also complete and that allows appropriate genetic counseling, it is that QF-PCR should be integrated into a protocol that considers clinical and ultrasound variables.

Neumomediastino espontáneo en paciente con COVID-19 / Sponteneous pneumomediastinum in patient with COVID-19

Introducción: El neumomediastino espontáneo o síndrome Hamman es una complicación poco frecuente y rara. Se define como la presencia de aire o gas dentro del mediastino sin una causa identificada. Objetivo: Presentar un caso clínico con una complicación poco frecuente, neumomediastino espontáneo, en un paciente con enfermedad por COVID-2019. Caso clínico: Paciente de 86 años con cuadro clínico manifestado por fiebre de 38o C y síntomas respiratorios (tos con secreción blanquecina, disnea de moderados esfuerzos). Se realiza prueba de reacción en cadena de polimerasa para enfermedad por coronavirus 2019, esta fue positiva. Al cuarto día de su hospitalización concurre con empeoramiento clínico dentro que lo destaca tos y disnea progresiva acompañado con saturación de oxigeno menor a 91 por ciento. Se realizaron estudios imagenológicos de alta resolución (angiotomografía computarizada de tórax) en la cual se evidencia la presencia de neumomediastino. Desarrollo: La pandemia por enfermedad por coronavirus 2019 ha dado lugar a una emergencia de salud pública a nivel mundial, en la que es importante que el personal de la salud esté familiarizados con los síntomas, los resultados de imágenes y con las complicaciones de esta enfermedad, como el neumomediastino encontrado en este caso. Conclusión . El neumomediastino espontáneo es una complicación poco frecuente que se presenta en la fase inflamatoria de esta enfermedad(AU)

Introduction: Spontaneous pneumomediastinum or Hamman syndrome is a rare and infrequent complication. It is defined as the presence of air or gas within the mediastinum without an identified cause. Objective: To report a clinical case of spontaneous pneumomediastinum in a patient with COVID-2019, a disease with a rare complication. Clinical case report: We report the case of an 86-year-old patient with a clinical condicion of fever of 38o C and respiratory symptoms (cough with whitish secretions, dyspnea on moderate exertion). He underwent a polymerase chain reaction test for coronavirus disease 2019, which resulted positive. On the fourth day of his hospitalization, he his clinical condition worsened, including cough and progressive dyspnea accompanied by oxygen saturation less than 91 percent. The presence of pneumomediastinum was revealed by high-resolution imaging studies (computed tomography angiography of the chest). Discussion: The 2019 coronavirus disease pandemic has given rise to a global public health emergency, which requires health personnel to be familiar with symptoms, imaging results, and complications of this disease, such as pneumomediastinum found in this case. Conclution: Spontaneous pneumomediastinum is a rare complication that occurs in the inflammatory phase of this disease(AU)

First report of fibropapillomatosis (FP) and Chelonid alphaherpesvirus 5 (ChHV5) in a green sea turtle (Chelonia mydas) from the historically fibropapillomatosis-free Fernando de Noronha Archipelago, Northeastern Brazil / Primeiro caso de fibropapilomatose (FP) e de Chelonid alphaherpesvirus 5 (ChHV5) em tartaruga-verde (Chelonia mydas) no Arquipélago de Fernando de Noronha, Nordeste do Brasil

Fibropapillomatosis (FP) is an infectious disease caused by Chelonid alphaherpesvirus 5 (ChHV5). Nevertheless, its clinical manifestations are considered multifactorial. Due to its relevance, FP is currently monitored in sea turtle populations in the United States, Australia, Caribbean, and Brazil. Between 2000 and 2020, the TAMAR Project/ TAMAR Project Foundation analyzed the prevalence of FP in nine states and oceanic islands along the Brazilian coast, including Fernando de Noronha Archipelago (FNA), a historically FP-free area. A total of 4,435 green sea turtles (Chelonia mydas) were monitored from 2010 to 2016. Additionally, in 2012 and 2014, 43 FP-free skin samples were analyzed for ChHV5 using a qualitative PCR for the UL30 polymerase (pol) sequence. In 2015, a bilateral ocular nodule characterized as an FP tumor was reported in one of the monitored individuals undergoing rehabilitation. Tissue samples were collected following surgical removal of the tumor. Characterization of a 454 bp UL30 polymerase gene revealed a ChHV5 sequence previously reported in other areas of the Atlantic Brazilian coast. In the years following this finding from January 2017 to March 2020, a total of 360 C. mydas were monitored in the same area and no FP tumors were detected. This is the first report of FP and the first detection of ChHV5 in FNA, a finding of great concern considering this site's historical absence of FP occurrence. This study highlights the importance of monitoring this disease in historically FP-free areas of the Brazilian Atlantic coast.(AU)

A fibropapilomatose (FP) é uma doença infecciosa causada pelo Chelonid alphaherpesvirus 5 (ChHV5). No entanto, as manifestações clínicas da doença são consideradas multifatoriais. Esta doença é monitorada atualmente em populações de tartarugas marinhas nos EUA, Austrália, Caribe e Brasil. Desde 2000, o Projeto TAMAR/Fundação Projeto TAMAR analisa a presença de FP em nove estados da costa brasileira e ilhas oceânicas, incluindo o arquipélago de Fernando de Noronha, uma área historicamente livre de FP. Um total de 4.435 indivíduos de Chelonia mydas foram monitorados de 2010 a 2016 e 43 amostras de pele foram analisadas para detectar ChHV5 em 2012 e 2014 com o objetivo de avaliar a presença do vírus em tecidos sem FP, usando uma PCR qualitativa para detecção de sequências do gene da UL30 polimerase. Em 2015, uma tartaruga verde (C. mydas) foi relatada com um nódulo ocular bilateral caracterizado como FP. Amostras de tecido foram coletadas durante sua reabilitação e procedimento cirúrgico para remover o tumor. A caracterização parcial de uma sequência de 454 bp do gene UL30 polimerase detectou ChHV5 anteriormente relatado em outras áreas da costa atlântica brasileira. Após estes achados, de janeiro de 2017 a março de 2020, um total de 360 indivíduos de C. mydas foram monitorados e nenhum caso de FP foi registrado. Este é o primeiro relato de FP e a primeira caracterização de ChHV5 no arquipélago de Fernando de Noronha, uma questão preocupante e que ressalta a importância do monitoramento desta doença em áreas historicamente livres de FP na costa atlântica brasileira.(AU)

Analysis of Salivary Bacterial Community by Direct PCR and High Resolution Melting Curve and Its Forensic Applications / 法医学杂志

OBJECTIVES@#To develop a rapid test for salivary bacterial community based on direct PCR (dPCR) and high resolution melting (HRM) curve analysis, to evaluate its application value in forensic medicine.@*METHODS@#The salivary bacteria were collected by centrifugation and then resuspended in Tris-EDTA (TE) buffer, and directly used as the template for amplification and HRM curve analysis (dPCR-HRM) of the 16S rDNA V4 region. The genotype confidence percentage (GCP) of the HRM profiles compared with the reference profile was calculated. The template DNA was extracted by traditional kit and then PCR-HRM (namely kPCR-HRM) was used as reference to validate the feasibility of dPCR-HRM. The gradient dilution templates, population samples and simulated salivary stains were analyzed by dPCR-HRM to evaluate its sensitivity, typing ability and adaptability.@*RESULTS@#Using dPCR-HRM method, the HRM profiles of salivary bacterial community were obtained within 90 minutes. The GCP between dPCR-HRM and kPCR-HRM was greater than 95.85%. For general individuals, the HRM type of bacterial community could be determined with 0.29 nL saliva by dPCR-HRM. The 61 saliva samples could be divided into 10 types. The typing of salivary stains deposited within 8 h was the same as those of fresh saliva (GCP>90.83%).@*CONCLUSIONS@#dPCR-HRM technology can be used for rapid typing of salivary bacterial community, and has the advantage of low cost and simple operation.

Establishment of Multiplex Amplification System of STR Loci in Felis Catus and Its Forensic Application / 法医学杂志

OBJECTIVES@#To construct a Felis catus STR loci multiplex amplification system and to evaluate its application value by testing the technical performance.@*METHODS@#The published Felis catus STR loci data were reviewed and analyzed to select the STR loci and sex identification loci that could be used for Felis catus individual identification and genetic identification. The fluorescent labeling primers were designed to construct the multiplex amplification system. The system was validated for sensitivity, accuracy, balance, stability, species specificity, tissue identity and mixture analysis, and investigated the genetic polymorphisms in 145 unrelated Felis catus samples.@*RESULTS@#Sixteen Felis catus autosomal STR loci and one sex determining region of Y (SRY) were successfully selected, and constructed a multiplex amplification system containing the above loci. The complete profile of all alleles could still be obtained when the amount of DNA template was as low as 0.25 ng. There was no specific amplification peak in other common animal samples. Population genetic surveys showed that total discrimination power (TDP) of the 16 STR loci was 1-3.57×10-20, the cumulative probability of exclusion (CPE) was 1-6.35×10-5 and the cumulative probability of matching was 3.61×10-20.@*CONCLUSIONS@#The Felis catus STR multiplex amplification system constructed in this study is highly sensitive, species-specific, and accurate in typing results, which can provide an effective solution for Felis catus species identification, individual identification and kinship identification in the field of forensic science.

PCR em tempo real no diagnóstico da toxoplasmose congênita / Real-time PCR in the diagnosis of congenital toxoplasmosis

O diagnóstico da toxoplasmose congênita apresenta limitações sendo, portanto, necessárias novas opções de exames. A análise do líquido aminiótico pela PCR em tempo real já se mostrou eficaz para confirmação da infecção fetal. No entanto, o seu desempenho em outras amostras biológicas ainda não está claro. O objetivo deste estudo é avaliar a PCR em tempo real no sangue da mãe e do recém-nascido assim como no líquido amniótico e placenta, no diagnóstico da toxoplasmose congênita. Esse é um estudo descritivo de gestantes com toxoplasmose acompanhadas no Rio de Janeiro, Brasil. Foi realizada PCR em tempo real em amostras de sangue materno, líquido amniótico, placenta e sangue dos recém-nascidos e o exame histopatológico das placentas. Também foram coletados dados clínicos e laboratoriais dos recém-nascidos. Foram acompanhadas 116 gestantes e analisadas 298 amostras. Uma (0,9%) gestante apresentou PCR positiva no sangue, três (3,5%) no líquido amniótico, uma (2,3%) na placenta e nenhum recém-nascido apresentou PCR positiva no sangue. O estudo histopatológico foi sugestivo de infecção por toxoplasmose em 24 (49%) placentas. Seis (5,2%) recém-nascidos foram diagnosticados com toxoplasmose congênita e apenas os casos com PCR positiva no líquido amniótico tinham associação do resultado da PCR com o diagnóstico de infecção congênita. Tanto as amostras de sangue materno quanto as de sangue dos recém-nascidos e placenta, não demonstraram ser promissoras no diagnóstico da toxoplasmose congênita. Novos estudos são necessários para avaliar o real papel do diagnóstico molecular em outros materiais biológicos que não o líquido amniótico.

The diagnosis of congenital toxoplasmosis has limitations so new options are needed. Real-time PCR analysis of amniotic fluid has proven effective for confirming fetal infection. However, its performance in other biological samples still needs to be determined. This study aims to evaluate the real-time PCR role in the blood of the mother and newborn as well as in the amniotic fluid and placenta, in congenital toxoplasmosis diagnosis. It is a descriptive study of pregnant women with toxoplasmosis followed in Rio de Janeiro, Brazil. Real-time PCR was performed on maternal blood, amniotic fluid, placenta, and newborn blood samples. In addition, a histopathological examination of the placentas was performed and data from the babies were collected. One hundred and sixteen pregnant women were followed and 298 samples were analyzed. One (0.9%) pregnant woman had positive PCR in the blood, three (3.5%) in the amniotic fluid, one (2.3%) in the placenta, and any newborn had positive PCR in the blood. The histopathological study suggested toxoplasmosis infection in 24 (49%) placentas. Six (5.2%) newborns were diagnosed with congenital toxoplasmosis and only the cases with positive PCR in amniotic fluid associated with the diagnosis of congenital infection. Neither maternal nor newborn blood and placenta samples have not shown promise in diagnosing congenital toxoplasmosis. Further studies are needed to evaluate the fundamental role of molecular diagnostics in others biological materials than amniotic fluid.

The Advances and Application of ABO Blood Group Genotyping Technology --Review / 中国实验血液学杂志

The ABO blood group system is the most important blood group system in clinical transfusion. Serological technology is a routine method for the identification of ABO blood groups, however, which have some limitations in the identification of complicated ABO samples with weakened antigens or antibodies, abnormal plasma proteins, polyagglutination, or cold agglutinin, etc. With the development of molecular biology technology, ABO blood group gene was cloned, and ABO blood group genotyping technology based on DNA was established. The genotyping technologies with different throughputs such as PCR-SSP, Droplet-AS-PCR, PCR-RFLP, PCR-SBT, SNaPshot, MALDI-TOF MS and NGS have emerged. Genotyping has overcome the limitations of serology, and has become an indispensable method to solve difficult blood type, providing strong support for the correct identification of ABO blood group, and providing guarantee for precision blood transfusion. This review summarizes the progress and application of ABO blood group genotyping methods.

Using multiple-fragment amplification combined with Gibson assembly to clone genes with site-directed mutations / 生物工程学报

In order to develop a simple and efficient site-directed mutagenesis solution, the Gibson assembly technique was used to clone the cyclin dependent kinase 4 gene with single or double site mutations, with the aim to simplify the overlap extension PCR. The gene fragments containing site mutations were amplified using a strategy similar to overlap extension PCR. Meanwhile, an empty plasmid was digested by double restriction endonucleases to generate a linearized vector with a short adaptor overlapping with the targeted gene fragments. The gene fragments were directly spliced with the linearized vector by Gibson assembly in an isothermal, single-reaction, creating a recombinant plasmid. After the recombinant plasmids were transformed into competent Escherichia coli DH5α, several clones were screened from each group. Through restriction analysis and DNA sequencing, it was found that the randomly selected clones were 100% target mutants. Since there was neither tedious multiple-round PCR amplification nor frequent DNA extraction operation, and there was no need to digest the original plasmid, this protocol circumvents many factors that may interfere with the conventional site-directed mutagenesis. Hence, genes with single or multiple mutations could be cloned easily and efficiently. In summary, the major defects associated with overlap extension PCR and rolling circle amplification were circumvented in this protocol, making it a good solution for site-directed mutagenesis.

Characterization of a family B DNA polymerase from Thermococcus eurythermalis A501 and its application in PCR / 生物工程学报

DNA polymerases are widely used in PCR and play important roles in life science research and related fields. Development of high-performance DNA polymerases is of great commercial interest as the current commercial DNA polymerases could not fully satisfy the requirements of scientific research. In this study, we cloned and expressed a family B DNA polymerase (NCBI accession number TEU_RS04875) from Thermococcus eurythermalis A501, characterized its enzymatic property and evaluated its application in PCR. The recombinant Teu-PolB was expressed in E. coli and purified with affinity chromatography and ion-exchange chromatography. The enzymatic properties of Teu-PolB were characterized using fluorescence-labeled oligonucleotides as substrates. The application potential of Teu-PolB in PCR was evaluated using the phage λ genomic DNA as a template. Teu-PolB has DNA polymerase and 3'→5' exonuclease activities, and is highly thermostable with a half-life of 2 h at 98 ℃. The most suitable PCR buffer is consisted of 50 mmol/L Tris-HCl pH 8.0, 2.5 mmol/L MgCl2, 60 mmol/L KCl, 10 mmol/L (NH4)2SO4, 0.015% Triton X-100 and 0.01% BSA, and the optimal extension temperature is 68 ℃. Under the optimized conditions, a 4 kb target fragment was successfully amplified with an extension rate of 2 kb/min. The yield of the Teu-PolB amplified-DNA was lower than that of Taq DNA polymerase, but its extension rate and fidelity was higher than that of Taq and Pfu DNA polymerases. The biochemical properties of Teu-PolB demonstrate that this enzyme can be used in PCR amplification with high thermostability, good salt tolerance, high extension rate and high fidelity.

Sistema para la Gestión de Personas Aisladas: solución informática para el Centro de Aislamiento UCI-MINSAP / Sistema para la Gestión de Personas Aisladas: IT solution for the Isolation Center UCI-MINSAP

La aplicación Sistema para la Gestión de Personas Aisladas (SGPA-UCI) fue desarrollada para informatizar el proceso de ingreso, pruebas de PCR y egreso de personas aisladas en el centro de aislamiento instalado en la Universidad de las Ciencias Informáticas (UCI), como parte del enfrentamiento a la Covid-19 en Cuba. Para el desarrollo de la aplicación se utilizó Symfony como framework de desarrollo y para el monitoreo de los datos, se diseñaron tableros con el empleo de Grafana. La solución informática facilitó la gestión de más de 10 mil personas aisladas en el centro de aislamiento, en un período de aproximadamente 6 meses, obteniendo los datos primarios de las personas y facilitando el proceso de ingreso, preparación de PCR, procesamiento de resultados recibidos y proceso de egreso. El sistema para la gestión de personas aisladas permitió el proceso de seguimiento a las personas en el centro de aislamiento UCI-MINSAP durante el enfrentamiento a la pandemia Covid-19(AU)

The System for the Management of Isolated Persons (SGPA-UCI) application was developed to computerize the process of admission, PCR tests and discharge of isolated people in the isolation center created in the University of Computer Sciences (UCI), as part of the confrontation with Covid-19 in Cuba. For the development of the application, Symfony was used as a development framework and for data monitoring, dashboards were designed using Grafana. The computer solution simplified the management of more than 10 thousand people isolated in the isolation center, in a period of approximately 6 months, obtaining the primary data of the people and facilitating the process of admission, preparation of PCR, processing of received results and exit process. The system for the management of isolated people allowed the process of monitoring people in the UCI-MINSAP isolation center during the confrontation with the Covid-19 pandemic(AU)

Polimorfismo genético del correceptor CCR5 en pacientes cubanos VIH/sida de la tercera edad / Genetic polymorphism of the CCR5 coreceptor in Cuban elderly HIV/AIDS patients

Introducción: El polimorfismo en algunos genes de quimiocinas se asocia con resistencia a la infección por VIH-1, en este sentido la presencia de la mutación Δ32 del correceptor CCR5 en homocigosis, se relaciona con resistencia a la infección y la mutación heterocigótica con un retraso en la progresión de la enfermedad. Objetivos: Identificar la frecuencia del polimorfismo genético del correceptor CCR5 en los pacientes bajo estudio, así como su relación con los niveles de linfocitos T CD4+, la carga viral y las enfermedades oportunistas. Métodos: Se realizó un estudio de corte transversal en 45 pacientes VIH/sida de la tercera edad, cubanos atendidos en el Centro Hospitalario Universitario del IPK durante los meses de enero a mayo de 2019 en el servicio de Medicina del Centro Hospitalario Universitario del IPK, a los que se les realizó la reacción en cadena de la polimerasa (PCR) para determinar el polimorfismo genético del correceptor CCR5. Resultados: El polimorfismo genético del correceptor CCR5 que predominó fue el homocigótico salvaje con 87 por ciento seguido del heterocigótico Δ32 con 13 por ciento. El 80 por ciento de los pacientes presentaron carga viral no detectable y el 56 por ciento niveles de linfocitos T CD4+ por encima de 350 cél/µL. La enfermedad oportunista que predominó fue la neumonía por Pneumocystis jirovecii en 32 por ciento de los sujetos estudiados. No se observaron diferencias estadísticamente significativas entre el polimorfismo genético del correceptor CCR5 y los niveles de linfocitos T CD4+, la carga viral y las enfermedades oportunistas presentes en los pacientes estudiados. Conclusiones: Los polimorfismos genéticos del correceptor CCR5 hallados fueron el homocigótico salvaje y el heterocigótico-∆32. Fue limitado el polimorfismo del gen en los pacientes estudiados(AU)

Introduction: Polymorphism in some chemokine genes is associated to resistance to HIV-1 infection. Homozygous Δ32 mutation of the CCR5 coreceptor is related to resistance to infection, whereas heterozygous mutation is related to a delay in the progress of the disease. Objectives: Identify the frequency of genetic polymorphism of the CCR5 coreceptor in the patients studied, as well as its relationship to CD4+ T lymphocyte levels, viral load and opportunistic diseases. Methods: A cross-sectional study was conducted of 45 Cuban elderly HIV/AIDS patients attending the Medicine Service of the University Hospital Center at IPK from January to May 2019. These patients underwent polymerase chain reaction testing (PCR) to determine genetic polymorphism of the CCR5 coreceptor. Results: A predominance was found of wild homozygotous genetic polymorphism of the CCR5 coreceptor with 87 percent, followed by heterozygotous Δ32 genetic polymorphism with 13 percent. In 80 percent of the patients studied the viral load was undetectable, whereas in 56 percent CD4+ T lymphocyte levels were above 350 cel/µl. The prevailing opportunistic disease was Pneumocystis jirovecii pneumonia in 32 percent of the subjects. Statistically significant differences were not found between genetic polymorphism of the CCR5 coreceptor and CD4+ T lymphocyte levels, viral load and the opportunistic diseases present in the patients studied. Conclusions: The genetic polymorphisms of the CCR5 coreceptor found in the study were of the wild homozygotous and heterozygotous Δ32 types. Gene polymorphism was limited in the patients studied(AU)

Técnicas de citogenética y biología molecular para el diagnóstico y seguimiento de la leucemia promielocítica / Cytogenetic and molecular biology techniques for the diagnosis and monitoring of promyelocytic leukemia

Introducción: La leucemia promielocítica es un subtipo de leucemia mieloide aguda que se presenta frecuentemente con una coagulopatía potencialmente mortal, por lo que representa una emergencia médica. En la gran mayoría de los pacientes ocurre la t(15;17)(q24;q21) que genera el gen aberrante PML-RARA. Mediante diferentes técnicas de citogenética y de la biología molecular que detectan dichas aberraciones es posible diagnosticar la entidad de manera inequívoca y estudiar la enfermedad mínima residual. Objetivo: Describir, comparar y analizar las técnicas de citogenética y de la biología molecular que son útiles para el diagnóstico y el seguimiento del paciente con leucemia promielocítica. Así como señalar sus ventajas y limitaciones. Métodos: Se realizó revisión de la bibliografía científica de los últimos cinco años relacionada con el tema a través de PUBMED. Se realizó análisis y resumen de la información. Análisis y síntesis de la información: Se describen dos técnicas de citogenética y tres moleculares basadas en la aplicación de la reacción en cadena de la polimerasa. Se comparan y analizan sus ventajas y limitaciones. Conclusiones: Algunas de estas técnicas son útiles únicamente para el diagnóstico, mientras que otras, por su alta sensibilidad, se recomiendan para el seguimiento del paciente con leucemia promielocítica(AU)

Introduction: Promyelocytic leukemia (PML) is a subtype of acute myeloid leukemia that frequently presents with a potentially fatal coagulopathy, therefore it represents a medical emergency. In the vast majority of patients, the t (15; 17) (q24; q21) occurs, which generates the aberrant gene PML-RARA. Using different cytogenetic and molecular biology techniques that detect these aberrations, it is possible to unequivocally diagnose the entity and study minimal residual disease. Objective: To describe, compare and analyze cytogenetics and molecular biology techniques that are useful for diagnosis and follow-up of the patient with Promyelocytic leukemia. As well as pointing out its advantages and limitations. Methods: A review of the scientific bibliography of the last five years related to the subject was carried out through PUBMED. An analysis and summary of the information was made. Analysis and synthesis of the information: Two cytogenetic and three molecular techniques are described based on the application of the polymerase chain reaction. Its advantages and limitations are compared and analyzed. Conclusions: Some of these techniques are only useful for diagnosis, while others, due to their high sensitivity, are recommended for monitoring the patient with Promyelocytic leukemia(AU)

Identification of genetic variants the CCKAR gene and based on body measurement and carcass quality characteristics in Qinchuan beef cattle (Bos taurus)

BACKGROUND: This study aimed to explore genetic polymorphisms of the CCKAR gene and their relationship with the growth and development of Qinchuan cattle which could be used as molecular markers for the improvement of the breeding of Qinchuan cattle. RESULTS: Here, we have identified seven single nucleotide polymorphisms (SNPs) at loci g. 1463 C>G; g. 1532 T>A; g. 1570 G>A; g. 1594 C>A; g. 1640 T>C; g. 1677 G>C; and g. 1735 C>T in the coding region of the bovine CCKAR gene. The frequencies identified on allelic and genotypic characteristics have shown that all seven SNPs diverged from the Hardy-Weinberg-Equilibrium. The SNP2, SNP3, SNP6 and SNP7 had the lowest polymorphism information content values, and remaining SNPs were found to be moderate (0.25 < PIC < 0.50). The genotype CG in SNP1 at loci g.1463 C>G had the greatest association with WH, HW, CD and CCF, while the genotype TA at the very same loci was associated with BFT, ULA and IMF content in Qinchuan cattle. The CCKAR gene expression level in adipose tissue, small intestine, liver and skeleton muscle was found to be higher, whereas, the expression level of mRNA in organs of other digestive system including reticulum, abomasum and omasum was moderate. Some expression of CCKAR mRNA was found in the large intestine, kidney and rumen. CONCLUSIONS: In summary, our finding suggested that the CCKAR gene could be used as a potential candidate for the improvement of carcass quality and body measurements of Qinchuan cattle.

Evolución de las infecciones por Pneumocystis Jirovecii en el Hospital de Pediatría Juan P. Garrahan / Evolution of Pneumocystis Jirovecii infections at Hospital de Pediatría Juan P. Garrahan

Pneumocystis jirovecii es un hongo oportunista, causante de neumonía en huéspedes inmunocomprometidos. Es una infección grave con elevada tasa de mortalidad en pacientes oncohematológicos y receptores de trasplante de células progenitoras hematopoyéticas. La administración de corticosteroides es el principal factor de riesgo para adquirir esta infección. Actualmente las infecciones ocurren en aquellos pacientes que no reciben adecuada profilaxis. Las técnicas de diagnóstico molecular son las recomendadas por su elevada sensibilidad, especificidad y rapidez. La frecuencia global de P. jirovecii en pacientes inmunocomprometidos de nuestro hospital, durante el período evaluado fue de 4,8%, con una mortalidad global del 20%. Como factores de mal pronóstico se reportan la presencia de coinfecciones y la necesidad de asistencia respiratoria mecánica. Es importante la sospecha precoz en pacientes de riesgo, confirmada con un diagnóstico preciso mediante métodos moleculares para una intervención adecuada y oportuna (AU)

Pneumocystis jirovecii is an opportunistic fungus, causing pneumonia in immunocompromised hosts. It is a severe infection with a high mortality rate in oncology/hematology patients and hematopoietic stem cell transplant recipients. The administration of corticosteroids is the main risk factor for acquiring this infection. Currently infections occur in patients who do not receive adequate prophylaxis. Molecular diagnostic techniques are recommended because of their high sensitivity, specificity, and speed. In the study period, the overall incidence of P. jirovecii in immunocompromised patients at our hospital was 4.8%, with an overall mortality rate of 20%. Factors of a poor prognosis are the presence of coinfections and the need for mechanical respiratory assistance. Early suspicion in high-risk patients is important to confirm the diagnosis through molecular studies and start adequate and early treatment (AU)