Preparation of the first national reference standard for determination of HEK293 cell DNA content / 中国生物制品学杂志

@#Objective To prepare a national reference standard for the quantification of HEK293 cell DNA content,so as to provide a support for the determination of residual DNA in HEK293 cells in the industry.Methods HEK293 cell DNA prepared using Genomic-tip 500/G and genomic DNA purification reagents was used as source materials,and the purity and content were assessed using ultraviolet spectrophotometry and agarose gel electrophoresis.After dilution to approximately 100 ng/μL,the DNA was aliquoted at 160 μL/tube.Five different laboratories were organized for collaborative calibration by using ultraviolet spectrophotometry, and the stability and applicability were evaluated.Results The HEK293 cell DNA national reference standard exhibited A_(260)/A_(280) ratios between 1.8 and 2.0 and displayed a single band on electrophoresis,meeting the specified criteria.Collaborative calibration across five laboratories yielded 78 valid data points with an average content of 104.8 ng/μL,a relative standard deviation(RSD) of 4.2%.The 95% confidence interval for the mean was 103.8—105.8 ng/μL,and the 95% reference range for single measurements was 96.0—113.6 ng/μL.The average confidence limit rate was 1.0%,and the recommended storage condition was-80 ℃.Applicability studies were conducted using two different models of fluorescence quantitative PCR instruments.The reference standard exhibited good applicability within the range of 0.3—3 000 pg/reaction,with amplification efficiencies of 101% and 95%,and R~2 values of 0.999 2 and 0.999 5 for the standard curves,respectively.Conclusion This batch of HEK293 cell DNA national reference standard meets all required specifications and can be utilized as a national reference standard for fluorescence quantitative PCR detection,with a certified content of 104.8 ng/μL,assigned batch number 270039-202301.

Astigmatism inclusivity of regional refractive intraocular lens / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effect of residual astigmatism on visual quality after phacoemulsification combined with regional refractive intraocular lens(IOL)implantation in patients with age-related cataract, and to evaluate the astigmatism inclusivity of regional refractive IOL.METHODS: Retrospective cohort study. The clinical data of 62 cases(73 eyes)of age-related cataract patients who underwent phacoemulsification combined with regional refractive IOL(Lentis Comfort LS-313 MF15)implantation from July 2020 to March 2022 at the ophthalmology department of our hospital were collected. They were grouped according to residual astigmatism at 6 mo postoperatively, taking 35 cases(40 eyes)with residual astigmatism of 0.75 D to 1.50 D as the experimental group, and 27 cases(33 eyes)with residual astigmatism ≤0.75 D as the control group. Visual acuity, defocus curves, objective visual acuity [wavefront aberrations, Strehl ratio(SR), modulation transfer functions(MTF)], subjective visual acuity(national eye institute visual function questionnaire-25), patients' satisfaction, and spectacle independence were compared between the two groups at 6 mo postoperatively.RESULTS:There was a difference in the preoperative astigmatism and the number of postoperative 6 mo residual astigmatism between the two groups(P<0.01). At 6 mo postoperatively, there was no difference in uncorrected distance, intermediate, and near visual acuity, objective visual quality, subjective visual quality, satisfaction, and spectacle independence between the two groups(P>0.05). The defocus curves showed that there was no difference in visual acuity between the two groups at all points in the +2.00 to -4.00 D defocus range of the additional spherical equivalent(P>0.05).CONCLUSION:Lentis Comfort LS-313 MF15 IOL was able to accommodate regular astigmatism of 1.50 D.

Research progress on dental materials for preventing root caries / 口腔疾病防治

@#The high incidence and untreated rate of root caries, a common and frequently occurring oral disease with challenging treatment in elderly individuals, is the main cause of tooth loss among elderly people, as rapid development results in pulpitis and periapical periodontitis or residual crown and root, which has been regarded as one of the common chronic oral diseases seriously affecting the quality of life of elderly people. Thus, early intervention and prevention are important. Traditional dental materials for preventing root caries have been widely used in clinical practice; however, they have the disadvantages of tooth coloring, remineralization and low sterilization efficiency. A series of new dental materials for preventing root caries have gradually become a research hotspot recently, which have the advantages of promoting the mineralization of deep dental tissue, prolonging the action time and enhancing adhesion. Future caries prevention materials should be designed according to the characteristics of root surface caries and the application population and should be developed toward simplicity, high efficiency and low toxicity. This review describes current research regarding anti-caries prevention material application, serving as a theoretical underpinning for the research of root caries prevention materials, which is important for both promotion in the effective prevention of root caries and improvement in the status of oral health and the quality of life among old people.

Impacto de la optimización del tratamiento hipolipemiante en el riesgo cardiovascular residual / Impact of Optimizing Lipid-Lowering Therapy on Residual Cardiovascular Risk

RESUMEN Introducción: el modelo SMART-REACH predice el riesgo de eventos cardiovasculares recurrentes. Objetivos: los objetivos de este estudio fueron: a) evaluar el riesgo residual en una población en prevención secundaria y niveles de colesterol asociado a lipoproteínas de baja densidad (C-LDL) fuera de meta; b) mediante un modelo de simulación, determinar el impacto de optimizar las terapias hipolipemiantes en términos de reducción del riesgo residual. Material y métodos: estudio transversal, descriptivo y multicéntrico. Se incluyeron consecutivamente pacientes con antecedentes cardiovasculares y un C-LDL mayor o igual que 55 mg/dL. El riesgo de eventos recurrentes (infarto agudo de miocardio, accidente cerebrovascular o muerte vascular) a 10 años y a lo largo de la vida se estimó utilizando el modelo SMART-REACH. Mediante una simulación, se optimizó el tratamiento hipolipemiante de cada paciente (utilizando estatinas, ezetimibe o inhibidores de proproteína convertasa subtilisina kexina tipo 9 [iPCSK9]), se estimó el descenso del C-LDL, se verificó el alcance del objetivo lipídico y se calculó la reducción del riesgo cardiovascular y el número necesario a tratar (NNT) correspondiente. Resultados: se incluyeron 187 pacientes (edad media 67,9 ± 9,3 años, 72,7% hombres). Los riesgos residuales calculados a 10 años y a lo largo de la vida fueron 37,1 ± 14,7% y 60,3 ± 10,7%, respectivamente. Globalmente, se pudo optimizar una sola estrategia farmacológica con estatinas, ezetimibe o un iPCSK9 en el 38,5%, el 11,5% y el 5,5% de la población, respectivamente. La optimización basada en dos tratamientos se realizó en el 27,5% (estatinas + ezetimibe), el 7,7% (estatinas + iPCSK9) y el 1,1% (ezetimibe + iPCSK9) de los casos. En 15 pacientes se optimizó el tratamiento considerando los tres fármacos. El 53,9% y el 62,9% de las acciones para optimizar el tratamiento mostraron un NNT menor que 30 para evitar un evento a 10 años o a lo largo de la vida, respectivamente. Conclusión: en este estudio, los pacientes con antecedentes cardiovasculares que no alcanzan la meta de C-LDL mostraron un riesgo residual considerable. La simulación mostró un importante margen para optimizar el tratamiento, con un impacto notable en el riesgo residual.

ABSTRACT Background: The SMART-REACH model predicts the risk or recurrent cardiovascular events. Objectives: The objectives of this study were: a) to evaluate the residual cardiovascular risk in a secondary prevention population with LDL-C levels above the recommended goal, using a simulation model; and b) to determine the impact of optimizing lipid-lowering therapies in terms of residual cardiovascular risk reduction. Methods: We conducted a cross-sectional, descriptive and multicenter study. Patient with a history of cardiovascular disease and a LDL-C ≥55 mg/dL were consecutively included. The 10-year and lifetime risk of recurrent events (myocardial infarction, stroke, or vascular death) were estimated using the SMART-REACH model. By means of a simulation, lipid-lowering treatment was optimized for each patient [using statins, ezetimibe and/or PCSK9 (PCSK9) inhibitors], with estimation of LDL-C reduction, checking if lipid-lowering goal was achieved and calculating the reduction in cardiovascular risk and the corresponding number needed to treat (NNT). Results: The cohort was made up of 187 patients; mean age was 67.9 ± 9.3 years and 72.7% were men. The calculated 10-year and lifetime residual risks were 37.1 ± 14.7% and 60.3 ± 10.7%, respectively. Overall, treatment was optimized with a single pharmacological strategy with statins, ezetimibe or PCSK9 inhibitor in 38.5%, 11.5% and 5.5% of the population, respectively. Optimization based on two treatments was performed in 27.5% (statins + ezetimibe), 7.7% (statins + PCSK9 inhibitor) and 1.1% (ezetimibe + PCSK9 inhibitor) of the cases. In 15 patients, treatment was optimized when the three drugs (statins + ezetimibe + PCSK9 inhibitor) were considered. Overall, 53.9% and 62.9% of the actions implemented to optimize treatment showed a 10-year or lifetime NNT < 30 to prevent an event, respectively. Conclusion: In this study, patients with a history of cardiovascular disease who do not reach LDL-C goal showed significant residual cardiovascular risk. The simulation model showed a significant margin for optimizing treatment, with a marked reduction in residual cardiovascular risk.

Silage quality and bacterial diversity of silages inoculated with Listeria monocytogenes and Lacticaseibacillus paracasei_6714

Introduction: King grass (Cenchrus purpureus (Schumach.) Morrone, syn. Pennisetum purpuphoides) and pineapple peel (Ananas comosus) silages are food alternatives for livestock in conditions of feed shortage. Objective: To describe the dynamics of the microbiota present in king grass and pineapple silage during the fermentation process using next generation sequencing (NGS) and to evaluate the protective effect of Lacticaseibacillus paracasei_6714 as a silage inoculum against Listeria monocytogenes. Methods: We used an unrestricted randomized design to characterize the microbiota present in silages made from king grass harvested 70 days after regrowth and pineapple peel. We inoculated mixtures of grass and peel with L. paracasei_6714 or L. monocytogenes, or both, with a non-inoculated treatment as control. The nutritional and fermentative profile was evaluated after 30 days. After 15 and 30 days of fermentation, we used 16S rRNA analysis to determine the dynamics and diversity of the microbiota in the inoculated and control silages. Result: Dry matter content and digestibility did not differ significantly; however, there were differences in crude protein, pH and organic acids. We obtained 4432 amplicon sequence variants of Proteobacteria, Firmicutes, Bacterioidetes, Actinobacteria, Verrucomicrobia, Planctomycetes and Patescibacteria. The relative abundance of each phylum varied depending on the material and fermentation period. Phylum similarity was over 70 % (but not greater than 50 % with Bray-Curtis at the species level). Conclusion: These bacterial communities seem to have an important role during silage fermentation. Proper management of silage processing can reduce or eliminate pathogenic bacteria.

Introducción: Los ensilajes del pasto king grass (Cenchrus purpureus (Schumach.) Morrone, syn. Pennisetum purpuphoides) y cáscaras de piña (Ananas comosus) son alternativas de alimento para ganado en condiciones de escasez alimentaria. Objetivo: Describir las dinámicas de la microbiota presente en los ensilajes de king grass y piña durante el proceso de fermentación usando secuenciación de próxima generación (NGS) y evaluar el efecto de protección de Lacticaseibacillus paracasei_6714 como inoculante de ensilaje ante Listeria monocytogenes. Métodos: Usamos un diseño aleatorio no restringido para caracterizar la microbiota presente en ensilajes de king Grass cosechados 70 días después de rebrote y de cáscaras de piña. Inoculamos mezclas de pasto y cáscara con L. paracasei_6714 o L. monocytogenes, o ambos, con un tratamiento control sin inocular. El perfil nutricional y de fermentación fue evaluado luego de 30 días. Después de 15 y 30 días de fermentación, usamos un análisis de para determinar la dinámicas y diversidad de la microbiota en los ensilajes inoculados y control. Resultados: Los contenidos de materia seca y digestibilidad, no difirieron significativamente; sin embargo, hubo diferencias en proteína cruda, pH y ácidos orgánicos. Obtuvimos 4 432 secuencias variantes de amplicon de Proteobacteria, Firmicutes, Bacterioidetes, Actinobacteria, Verrucomicrobia, Planctomycetes y de Patescibacteria. La abundancia relativa de cada filo vario dependiendo del material y periodo de fermentación. Similitudes de filo fueron mayores al 70 % (pero no mayor que 50 % con Bray-Curtis a nivel de especie). Conclusión: Estas comunidades bacterianas parecen cumplir un papel importante durante la fermentación del ensilaje. Un manejo apropiado del proceso de ensilaje puede reducir o eliminar baterías patogénicas.

Comparative study of small incision refractive lenticule extraction with 5 mm versus 6.5 mm optic zone for myopia

Purpose: To compare residual stromal thickness (RST) in eyes undergoing small incision refractive lenticule extraction (SMILE) using a lenticular diameter of 6.5 mm versus those with a diameter of 5 mm. Methods: In this retrospective comparative case series, consecutive patients who underwent SMILE between 2016 and 2021 with at least 6 months of follow?up were included. Preoperative best?corrected distance visual acuity (BCDVA), refractive error, contrast sensitivity, central corneal thickness, keratometry, higher order aberrations, and scotopic pupil size were recorded using a Placido disk topography with Sheimpflug tomography?based system. Patients underwent SMILE with a lenticular diameter of 6.5 mm until 2018 (n = 372 eyes). Thereafter, the lenticular diameter was reduced to 5 mm (n = 318). The RST, postoperative refraction, aberrations, subjective glare, and halos were compared across groups at 1 and 6 months. Results: The mean age of participants was 26.8 ± 5.8 years with a mean preoperative spherical equivalent of ?4.48 D ± 2.16 D (range: ?0.75 to ?12.25 D) and mean scotopic pupil of 3.7 ± 0.75 mm. Eyes in the 5 mm group had 30.6 m (95% confidence interval [CI] = 28 to 33 m, P < 0.001) greater RST compared to the 6.5 mm group after adjusting for spherical equivalent and preoperative pachymetry. There were no differences in vision, contrast sensitivity, aberrations (wavefront error of 0.19 ± 0.2 vs. 0.25 ± 0.2, P = 0.19) or glare between the two groups. Conclusion: SMILE performed with a lenticular diameter of 5 mm leads to greater RST across the myopic range, but without inducing significant higher?order aberrations.

Enfermedad mínima residual en leucemia mieloide aguda no promielocítica: Resultados preliminares de un estudio colaborativo internacional / Minimal residual disease in non-myelocytic acute myeloid leukemia: preliminary results of an international collaborative study

A pesar de los avances en los protocolos de tratamiento y en las medidas de soporte en pacientes con Leucemia Mieloide Aguda (LMA), 27% presentan recaídas de la enfermedad. Esto se debe, entre otras causas, a la persistencia de pequeñas cantidades de células malignas (blastos) resistentes a la terapia. Estas pequeñas cantidades de blastos remanentes se denominan Enfermedad Mínima Residual (EMR). La determinación de EMR requiere de técnicas no solo muy sensibles, sino también específicas, y permite evaluar la respuesta individual a la terapia. La introducción de la EMR como parámetro de respuesta y estratificación está bien definida en Leucemia Linfoblástica Aguda (LLA). Por el contrario, aunque existen publicaciones sobre el impacto pronóstico de la EMR en LMA, aún no se encuentra incluida en forma sistemática en los protocolos nacionales actuales, entre otros motivos, por lo laborioso de la determinación y por la necesidad de validación de la misma. Debe tenerse en cuenta que el inmunofenotipo de los blastos mieloides suele ser más heterogéneo que el de los blastos en LLA, presentando, en muchos casos, subpoblaciones diferentes entre sí, lo cual dificulta su detección certera y no hay consenso definido en cuanto a la metodología más eficaz. En este trabajo describimos una nueva estrategia de marcación y análisis estandarizada en un estudio multicéntrico internacional para LMA y la utilidad de la EMR como parámetro de respuesta y de estratificación. Asimismo, detallamos los resultados preliminares de nuestra cohorte de pacientes (AU)

Despite the improvement in treatment and supportive care of patients with Acute Myeloid Leukemia (AML), 27% of them relapse. This is due to the persistence of small amounts of malignant cells (blasts) resistant to therapy, among other causes. These small amounts of blasts are called Minimal Residual Disease (MRD). The determination of MRD requires not only techniques with high sensitivity but also with high specificity, and allows to evaluate the individual response to treatment. The introduction of MRD as a response parameter is well established in Acute Lymphoblastic Leukemia (ALL), and it is used in current stratification protocols. On the other hand, even though there are some reports regarding the prognostic impact of MRD in AML, it is still not included in the current national protocols due to the lack of validation of the determination, among other causes. This is due to the fact that the immunophenotype of myeloid blasts is more heterogeneous than in ALL, presenting different subpopulations, which difficults their accurate detection. Thus, there is still no consensus regarding the most effective approach. In this article, we describe a new staining and analysis strategy standardized by an international multicentric study, and the utility of EMR as a response and stratification parameter. Additionally, we show the preliminary results of our patient cohort. (AU)

Novel custom designed toric piggyback intraocular lens for the correction of residual postoperative astigmatism

We report the outcomes of a custom-designed toric piggyback intraocular lens in a patient with high postoperative residual astigmatism. A 60-year-old male patient underwent customized toric piggyback IOL for postoperative residual astigmatism of 13 D, with follow-up examinations for IOL stability and refractive outcomes. The refractive error stabilized at two months and remained stable at one year, with a correction of nearly 9 D of astigmatism. The IOP remained within normal limits, and there were no postoperative complications. The IOL remained stable in the horizontal position. To our knowledge, this is the first case report of correction of unusually high astigmatism by a novel smart toric design of piggyback IOL.

Analysis of drying kinetic of brewer ́s spent grains: effect of the temperature on the physical properties and the content of bioactive compounds / Análisis de la cinética de secado del bagazo residual de malta: efecto de la temperatura sobre las propiedades físicas y el contenido de compuestos bioactivos

Background: Brewer ́s spent grain (BSG) is a biomass by-product generated in large volumes during industrial beer production. BSG has become a growing environmental problem, as most breweries discard it inappropriately, negatively impacting the environment. Alternatives for the exploitation of this by-product have consisted of elaborating food supplements for farm animals, obtaining biofuels, developing adsorbents, and obtaining substances for the food industry. However, the high moisture content in BSG (approximately 70%), poses a significant challenge in exploring various reuse alternatives. Therefore, the implementation of a pre-drying process becomes essential. Objective: This study aimed to analyze the BSG drying kinetics at different temperatures and the effect of the drying temperature on the physical properties and the content of bioactive compounds. Methods: BSG samples were dried at different temperatures (50, 60, 70, 80, 90, and 105°C) and analyzed for their moisture ratio, water activity, total polyphenol content (TPC), and DPPH (1,1-diphenyl-2-picrylhydrazil) radical scavenging activity. Also, four kinetics models were fitted to the drying data. Results:It was determined that the effective diffusivity was between 5.23x10

Antecedentes: El Bagazo residual de malta (BSG por sus siglas en inglés) es un subproducto biomásico generado en grandes volúmenes durante la producción industrial de cerveza. El BSG se ha convertido en un creciente problema para el medio ambiente, debido a que la mayoría de las cervecerías descartan inapropiadamente este residuo generando un impacto negativo al ambiente. Las alternativas para el aprovechamiento de este subproducto han consistido especialmente en la elaboración de suplementos alimenticios para animales de granja, obtención de biocombustibles, desarrollo de adsorbentes y obtención de productos para la industria alimentaria. Sin embargo, el alto contenido de humedad (~70%) del BSG representa un reto para el desarrollo de diferentes alternativas de reutilización, por lo que se hace necesario un proceso de secado previo. Objetivos: En este estudio se analizó la cinética de secado del BSG a diferentes temperaturas y el efecto de la temperatura de secado sobre sus propiedades físicas y contenido de compuestos bioactivos. Métodos: Las muestras de BSG fueron secadas a diferentes temperaturas (50, 60, 70, 80, 90 y 105°C) y analizadas en términos de razón de humedad, actividad acuosa, contenido de polifenoles totales (TPC) y actividad secuestradora del radical DPPH. Además, se ajustaron 4 modelos cinéticos a los datos de secado. Resultados: Se determinó que la difusividad efectiva del BSG varió entre 5.23x10

Diagnóstico por imagen de abscesos hepáticos y pulmonares por estreptococos del grupo viridans. Presentación de caso / Imaging diagnosis of liver and lung abscesses due to viridans streptococci. Case presentation

Resumen El Streptococcus viridans es conocido más comúnmente como agente infeccioso en las endocarditis, sin embargo, poco se conoce sobre su potencial infeccioso en otros órganos o sistemas, donde ha demostrado una elevada mortalidad. El reconocimiento del Streptococcus viridans como agente productor de abscesos en otras localizaciones como a nivel hepático o pulmonar, permitirá un diagnóstico oportuno mediante los distintos métodos de imagen, reduciendo las graves consecuencias para el paciente y los tiempos de hospitalización. Se presenta el caso de un paciente del sexo masculino de 33 años de edad sin antecedentes crónico degenerativos, que inició con sintomatología 7 meses previos a su ingreso, con fiebre intermitente, fatiga, astenia, anorexia y pérdida de peso. A la exploración física presentó dolor a la palpación media y profunda en hipocondrio derecho, en el panel de laboratorios presentó llamativa neutrofilia, en la tomografía de tórax y abdomen se mostró lesión cavernomatosa en pulmón y quistes complicados hepáticos, a los cuales se les realizó drenaje percutáneo guiado por ultrasonido, con envío de muestras a cultivo con resultado positivo para Streptococcus viridans, lo que permitió brindar el tratamiento dirigido al paciente, y que remitiera la enfermedad.

Abstract Streptococcus viridans is more commonly known as an infectious agent in endocarditis, however, little is known about its infectious potential in other organs or systems, where it has shown high mortality. The recognition of Streptococcus viridans as an abscess-producing agent in other locations, such as the liver or lungs, will allow timely diagnosis using different imaging methods, reducing serious consequences for the patient and hospitalization times. We present the case of a 33-year-old male patient with no chronic degenerative history, who started symptoms 7 months prior to admission, with intermittent fever, fatigue, asthenia, anorexia and weight loss, on physical examination he presented pain at the medium and deep palpation in the right hypochondrium, in the laboratory panel I present striking neutrophilia, in the tomography of the thorax and abdomen a cavernous lesion in the lung and complicated hepatic cysts are shown, to which percutaneous drainage guided by ultrasound is performed, with sending of cultured samples with a positive result for Streptococcus viridans. Thus, allowing treatment to be provided to the patient, thereby achieving remission of the disease.

Study on the influence of Barbecure combined with Epley on residual dizziness of horizontal canal benign paroxysmal positional vertigo by SRM-vertigo diagnosis system / 临床耳鼻咽喉头颈外科杂志

Objective:To investigate the influence of Barbecure combined with Epley on residual dizziness of horizontal canal benign paroxysmal positional vertigo（HC-BPPV） by SRM-vertigo diagnosis system. Methods:A total of 406 patients diagnosed with HC-BPPV from Nov 2021 to Nov 2022 were enrolled by rapid axial roll test and Dix-Hallpike in the department of Otorhinolaryngology Head and Neck Surgery, the First Affiliated Hospital of Xi'an Jiaotong University. The patients were divided into two groups by hospital card numbers, in which the numbers that were odd were considered as group A, and the numbers that were even were considered as group B. The group A underwent two circles of Barbecure repositioning procedure by SRM-vertigo diagnosis system, while the group B underwent two circles Barbecure combined with Epley repositioning procedure by SRM-vertigo diagnosis system. The treatment was stopped on the next day when two groups of patients were cured, and those who were not cured will continue treatment with the same method. Results:The cure rate of group A was 83.41%, and the cure rate of group B was 80.51%, the difference between the two groups was not-statistically significant difference（P>0.05）. The rate of residual dizziness of group A was 23.30%, the rate of residual dizziness of group B was 11.46%, the difference between the two groups was statistically significant（P<0.05）. Conclusion:The Barbecure combined with Epley otoliths repositioning maneuver by SRM-vertigo diagnosis system can significantly reduce the rate of residual dizziness after the treatment of HC-BPPV, and improve the quality of life of patients.

Optimization and application of caprylic acid precipitation in the purification of monoclonal antibody / 生物工程学报

In response to the market demand for therapeutic antibodies, the upstream cell culture scale and expression titer of antibodies have been significantly improved, while the production efficiency of downstream purification process is relatively fall behind, and the downstream processing capacity has become a bottleneck limiting antibody production throughput. Using monoclonal antibody mab-X as experimental material, we optimized the caprylic acid (CA) precipitation process conditions of cell culture fluid and low pH virus inactivation pool, and studied two applications of using CA treatment to remove aggregates and to inactivate virus. Based on the lab scale study, we carried out a 500 L scale-up study, where CA was added to the low pH virus inactivation pool for precipitation, and the product quality and yield before and after precipitation were detected and compared. We found that CA precipitation significantly reduced HCP residuals and aggregates both before and after protein A affinity chromatography. In the aggregate spike study, CA precipitation removed about 15% of the aggregates. A virus reduction study showed complete clearance of a model retrovirus during CA precipitation of protein A purified antibody. In the scale-up study, the depth filtration harvesting, affinity chromatography, low pH virus inactivation, CA precipitation and depth filtration, and cation exchange chromatography successively carried out. The mixing time and stirring speed in the CA precipitation process significantly affected the CA precipitation effect. After CA precipitation, the HCP residue in the low pH virus inactivation solution decreased 895 times. After precipitation, the product purity and HCP residual meet the quality criteria of monoclonal antibodies. CA precipitation can reduce the chromatography step in the conventional purification process. In conclusion, CA precipitation in the downstream process can simplify the conventional purification process, fully meet the purification quality criterion of mab-X, and improve production efficiency and reduce production costs. The results of this study may promote the application of CA precipitation in the purification of monoclonal antibodies, and provide a reference for solving the bottleneck of the current purification process.

Clinical application of normalized residual activity as a semiquantitative adjunct in assessing renal emptying in pediatric diuretic scans

Background@#The most recent pediatric diuretic imaging guidelines recommend the use of normalized residual activity (NORA) as a semiquantitative index of renal tracer drainage. It is defined as the ratio of post-void renal counts to 1-2 minute post-injection renal counts, with values less than 1 indicative of good drainage. We present two instances where NORA calculation was adjunctive in the evaluation of obstructive uropathy. @*Case Presentation@#The first patient was a 3-month-old male with left-sided congenital hydronephrosis. On dynamic imaging, the diseased kidney showed adequate perfusion and parenchymal extraction; moderate to severe pelvicalyceal tracer retention exhibited good response to diuretic. The pre-diuretic NORA of 1.62 declined to 0.28 after furosemide challenge, concordant with imaging findings that were negative for obstruction. The second patient was a 7-week-old male, also with congenital hydronephrosis of the left kidney. Dynamic images showed the diseased kidney with diminished perfusion and function, as well as pelvicalyceal tracer retention which became more severe after the diuretic was given. The pre-diuretic NORA was 1.81, which became 1.18 post-diuretic. This inadequate decline supplemented imaging findings pointing to significant obstruction. Other semiquantitative parameters have preceded NORA; however, clearance half-time is not validated as a marker of obstructive uropathy in infants and children, and output efficiency requires specialized software to calculate. Standardization of NORA determination is largely provided for by the guidelines recommending a perirenal background region of interest, as well as minimizing the interval between starting camera acquisition and injecting the tracer. @*Conclusion@#Semiquantitative analysis through NORA calculation gives relevant supporting information in the reporting of renal tracer drainage among pediatric patients. Further studies are needed to ascertain its applicability among adults and its diagnostic value in a larger sample of affected Filipino children.

Association between residual cholesterol and the risk of subclinical renal damage / 西安交通大学学报(医学版)

【Objective】 Dyslipidemia has shown to be associated with cardiovascular, metabolic and renal diseases. This study aimed to investigate the association between residual cholesterol and the risk of subclinical renal damage (SRD). 【Methods】 A total of 2 342 participants were recruited from the previously established Hanzhong Adolescent Hypertension Study cohort. According to estimated glomerular filtration rate(eGFR) and urinary albumin-to-creatine ratio(uACR), the subjects were divided into SRD group and non-SRD group. The associations of residual cholesterol with eGFR, uACR, and the risk of SRD were analyzed by multiple linear and Logistic regression analyses. 【Results】 Residual cholesterol was positively correlated with uACR(r=0.081, P<0.001) but negatively correlated with eGFR (r=-0.091, P<0.001). Multiple linear regression analysis revealed that residual cholesterol was an influencing factor of uACR (β=0.075, P<0.001) and eGFR (β=-0.027, P<0.001) after adjustment for gender, age, smoke, alcohol, exercise, BMI, hypertension, diabetes and serum uric acid. In addition, Logistic regression analysis revealed that residual cholesterol was significantly associated with the risk of SRD independently of potential confounders [OR(95% CI)=1.387 (1.113-1.728), P<0.001]. Further subgroup analysis showed that residual cholesterol was significantly associated with the risk of SRD in women but not in men. 【Conclusion】 Residual cholesterol is a contributing factor in the risk of subclinical renal damage with gender-specific association.

Study on Analytical Method of Leachable Substances of Allogeneic Products / 中国医疗器械杂志

Products made from allogeneic tissue are largely used in clinical treatment due to its wide source compared with autologous tissue, causing less secondary trauma of patients and the good biocompatibility. Various organic solvents and other substances introduced in the production process of allogeneic products will leach down into the human through clinical treatment, thus bringing varying degrees of harm to patients. Therefore, it is very necessary to detect and control the leachables in such products. Based on the classification and summary of leachable substances existing in the allogeneic products, the preparation of extract and the establishment of the detection techniques for known and unknown leachable are briefly introduced in this study, in order to provide research method for the study of leachable substances of allogeneic products.

Correlation Analysis between Cerebrospinal Fluid Status and Prognosis in Childhood with Acute Lymphoblastic Leukemia by Flow Cytometry / 中国实验血液学杂志

OBJECTIVE@#To study the cerebrospinal fluid (CSF) status and prognosis value in patients with newly diagnosed acute lymphoblastic leukemia (ALL) by flow cytometry (FCM).@*METHODS@#The clinical features of the 75 newly diagnosed ALL patients from September 2020 to December 2021 in our centre were retrospective analyzed, as well as the bone marrow (BM) and CSF minimal residual disease (MRD) data, and the CSF conventional cytology data. Central nervous system infiltration(CNSI) positive was as CSF MRD positive by FCM or leukemia cells detected by conventional cytology. The status of CSF were compared and analyzed by FCM and conventional cytology, the clinical features and the prognosis value of different CNSI status in these patients were analyzed.@*RESULTS@#Among 75 newly diagnosed ALL, 16 cases (21%) with CNSI positive (CNSI+) were detected by FCM, while only 2 positive cases (3%) were detected by conventional cytology. The CNSI+ rate detected by FCM was significantly higher than conventional cytology(P<0.05). Compared with CNSI- ALL patients, the median age of CNSI+ ALL patients was significantly younger, and the median platelet count was significantly lower, the difference was statistically significant (P<0.05). Up to follow-up time (August 31, 2022), four ALL patients were died, including 3 patients were CNSI- and 1 patient was CNSI+. Furthermore, three cases were primary disease relapse, including 1 case was CNSI+. There was no significant difference in overall survival (OS) rate and relapse-free survival (RFS) rate of the patients with different CNSI status.@*CONCLUSION@#Compared with conventional cytology, FCM is a more sensitive assay to evaluate the central nervous system status in ALL patients. After active treatment, there was no significant difference in OS and RFS between patients with different CNSI status at diagnosis.

Research Progress of Next Generation Sequencing in Acute Leukemia --Review / 中国实验血液学杂志

With the advent of precision medicine, next-generation sequencing (NGS) is playing an increasingly important role in clinical oncology diagnosis and treatment with its advantages of high sensitivity, high accuracy, high efficiency and operability. NGS reveals the genetic characteristics of acute leukemia(AL) patients by screening for specific disease-causing genes to identify occult as well as complex genetic mutations in patients with AL, leading to early diagnosis and targeted drug therapy for AL patients, as well as to predict disease recurrence by detecting mnimal residual disease (MRD) and analyzing mutated genes to determine patient prognosis. NGS plays an increasingly important role in the diagnosis, treatment and prognosis assessment in AL, providing a direction for the pursuit of precision medicine. This paper reviews the research progress of NGS in AL.

Electrocardiogram signal classification based on fusion method of residual network and self-attention mechanism / 生物医学工程学杂志

In the diagnosis of cardiovascular diseases, the analysis of electrocardiogram (ECG) signals has always played a crucial role. At present, how to effectively identify abnormal heart beats by algorithms is still a difficult task in the field of ECG signal analysis. Based on this, a classification model that automatically identifies abnormal heartbeats based on deep residual network (ResNet) and self-attention mechanism was proposed. Firstly, this paper designed an 18-layer convolutional neural network (CNN) based on the residual structure, which helped model fully extract the local features. Then, the bi-directional gated recurrent unit (BiGRU) was used to explore the temporal correlation for further obtaining the temporal features. Finally, the self-attention mechanism was built to weight important information and enhance model's ability to extract important features, which helped model achieve higher classification accuracy. In addition, in order to mitigate the interference on classification performance due to data imbalance, the study utilized multiple approaches for data augmentation. The experimental data in this study came from the arrhythmia database constructed by MIT and Beth Israel Hospital (MIT-BIH), and the final results showed that the proposed model achieved an overall accuracy of 98.33% on the original dataset and 99.12% on the optimized dataset, which demonstrated that the proposed model can achieve good performance in ECG signal classification, and possessed potential value for application to portable ECG detection devices.

MinerVa: A high performance bioinformatic algorithm for the detection of minimal residual disease in solid tumors / 生物医学工程学杂志

How to improve the performance of circulating tumor DNA (ctDNA) signal acquisition and the accuracy to authenticate ultra low-frequency mutation are major challenges of minimal residual disease (MRD) detection in solid tumors. In this study, we developed a new MRD bioinformatics algorithm, namely multi-variant joint confidence analysis (MinerVa), and tested this algorithm both in contrived ctDNA standards and plasma DNA samples of patients with early non-small cell lung cancer (NSCLC). Our results showed that the specificity of multi-variant tracking of MinerVa algorithm ranged from 99.62% to 99.70%, and when tracking 30 variants, variant signals could be detected as low as 6.3 × 10 -5 variant abundance. Furthermore, in a cohort of 27 NSCLC patients, the specificity of ctDNA-MRD for recurrence monitoring was 100%, and the sensitivity was 78.6%. These findings indicate that the MinerVa algorithm can efficiently capture ctDNA signals in blood samples and exhibit high accuracy in MRD detection.

Automatic sleep staging algorithm for stochastic depth residual networks based on transfer learning / 生物医学工程学杂志

The existing automatic sleep staging algorithms have the problems of too many model parameters and long training time, which in turn results in poor sleep staging efficiency. Using a single channel electroencephalogram (EEG) signal, this paper proposed an automatic sleep staging algorithm for stochastic depth residual networks based on transfer learning (TL-SDResNet). Firstly, a total of 30 single-channel (Fpz-Cz) EEG signals from 16 individuals were selected, and after preserving the effective sleep segments, the raw EEG signals were pre-processed using Butterworth filter and continuous wavelet transform to obtain two-dimensional images containing its time-frequency joint features as the input data for the staging model. Then, a ResNet50 pre-trained model trained on a publicly available dataset, the sleep database extension stored in European data format (Sleep-EDFx) was constructed, using a stochastic depth strategy and modifying the output layer to optimize the model structure. Finally, transfer learning was applied to the human sleep process throughout the night. The algorithm in this paper achieved a model staging accuracy of 87.95% after conducting several experiments. Experiments show that TL-SDResNet50 can accomplish fast training of a small amount of EEG data, and the overall effect is better than other staging algorithms and classical algorithms in recent years, which has certain practical value.