Shedding of infectious SARS-COV-2 in two asymptomatic children / Excreción de SARS-CoV-2 infeccioso en dos niños asin tomáticos

Abstract Asymptomatic infections with SARS-CoV-2 are associ ated with viral transmission and have a key role in the propagation of the pandemic. Understanding viral shed ding during asymptomatic infections is critical. Unfor tunately, data on asymptomatic SARS-CoV-2 infection in children is extremely limited. To determine the presence of viral viable shedding, we prospectively followed two healthy children of a family where both parents devel oped mild COVID-19 (April 2021). SARS-CoV-2 detection was made by RT-PCR and virus isolation by cell culture from saliva samples. Positive samples were sequenced to identify variants of SARS-CoV-2. Serum samples were evaluated to determine the presence of antibodies using a single enzyme-linked immunosorbent assay (ELISA, COVIDAR IgG). Both children were SARS-CoV-2 positive and asymptomatic. In addition, the virus grew in cell cul ture from saliva samples. Furthermore, one child showed viable SARS-CoV-2 for at least 17 days after the onset symptoms from his father. The recommended isolation period for asymptomatic contacts during the acquisition of data had been established for 10 days; however, this child remained with viable virus beyond that period. The positive samples from both children were consistent with B.1.1.28.1 lineage (Gamma). In both asymptomatic children, anti-Spike IgG was detected. Asymptomatic children may represent a source of infection that should not be underestimated during this pandemic.

Resumen Las infecciones asintomáticas por SARS-CoV-2 están asociadas a la transmisión viral y tienen un papel cla ve en la propagación de la pandemia. Comprender la excreción viral durante las infecciones asintomáticas es fundamental. Desafortunadamente, los datos sobre la infección asintomática por SARS-CoV-2 en niños son extremadamente limitados. Para determinar la presencia de excreción de virus viable, se siguió prospectivamente a dos niños sanos de una familia en la que ambos padres desarrollaron COVID-19 leve (abril 2021). La detección de SARS-CoV-2 se realizó por RT-PCR y el aislamiento del virus por cultivo celular a partir de muestras de saliva. Las muestras positivas se secuenciaron para identificar variantes de SARS-CoV-2. En las muestras de suero se determinó la presencia de anticuerpos utilizando un ensayo de ELISA (COVIDAR IgG). Ambos niños fueron positivos para SARS-CoV-2 y asintomáticos. Además, el virus creció en cultivos celulares a partir de muestras de saliva. Uno de los niños mantuvo SARS-CoV-2 via bles durante al menos 17 días después de la aparición de los síntomas de su padre. El período de aislamiento recomendado para contactos asintomáticos durante la adquisición de datos se había establecido en 10 días, sin embargo, este niño permaneció con virus viable más allá de ese período. Las muestras positivas de estos niños correspondieron al linaje B.1.1.28.1 (Gamma). En ambos niños asintomáticos se detectó anticuerpos IgG anti-Spike. Concluimos que los niños asintomáticos pueden representar una fuente de infección que no debe subestimarse durante esta pandemia.

Characteristics of viral shedding in people infected with SARS-CoV-2 during difference stages / 中国热带医学

@#Abstract: Viral shedding of SARS-CoV-2 is a continuous dynamic process, which can be divided into latent stage, initial stage, peak stage and decreasing stage according to the characteristics of viral shedding. After being infected with SARS-CoV-2, the infected person generally stays in the latent period for 1-3 days, which is characterized by continuous negative nucleic acid test results and no infectiousness, and the risk of infection for close contacts is very low. At the initial stage of viral shedding is characterized by a rapid decline in the Ct value of nucleic acid tests in a short time, and clinical symptoms gradually appear. The infectiousness of the infected person gradually increases during this period, and the risk of infection for close contacts also gradually increases, but it is still in the early stage of infection, the possibility of viral shedding is low, and the risk of infection of secondary close contacts is low. The peak of viral shedding is characterized by low Ct value in nucleic acid test and obvious clinical symptoms; during this period, the infected person is the most infectious, and the risk of infection of the contact is the highest, so the scope of close contacts should be expanded appropriately. The decreasing period is characterized by the gradual increase of Ct value of nucleic acid test and the gradual disappearance of clinical symptoms; during this period, the infectiousness of the infected person gradually decreases to disappear. In an outbreak, an infected person in the decreasing phase is more likely to be an early infected person in the transmission chain. If infected individuals in the decreasing phase are found in an area without a SARS-CoV-2 epidemic, it suggests that the local outbreak epidemic has been spreading for some time and may be larger in scale. According to the characteristics of viral shedding, risk personnel can be determined more scientifically and accurately, so as to minimize the risk and reduce the waste of epidemic prevention resources.

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.

Assessment of mycoplasma vaccine efficacy in reducing infection with Newcastle disease virus

The present work recorded the impact of using Mycoplasma gallisepticum vaccines on post-vaccinal response and protection against challenge with Newcastle disease virus. Specific pathogen-free chickens were divided into eight groups of forty chickens each. Group G1 was vaccinated with Mycoplasma gallisepticum live attenuated and Mycoplasma gallisepticum inactivated vaccines. Group G2 was vaccinated with Mycoplasma gallisepticum live attenuated, Mycoplasma gallisepticum inactivated and Newcastle disease inactivated vaccines. Group G3 was vaccinated with Mycoplasma gallisepticum live attenuated vaccine. Group G4 was vaccinated with Mycoplasma gallisepticum live attenuated and Newcastle disease inactivated vaccines. Group G5 was vaccinated with Mycoplasma gallisepticum inactivated vaccine. Group G6 was vaccinated with Mycoplasma gallisepticum inactivated and Newcastle disease inactivated vaccines. Group G7 was vaccinated with Newcastle disease inactivated vaccine. Group G8 was kept as non-vaccinated control. The Newcastle disease hemagglutination inhibition antibodies and mortality percentages were measured. Group G7 recorded the best protective Newcastle disease hemagglutination inhibition antibody titer (7 log2). Group G2 recorded a marginal satisfactory antibody titer (6 log2) after vaccination by the three tested vaccines. The remaining groups revealed unsatisfactory titers ranged from 0-5. The protection levels for G2, G4, G6 and G7 ranged from 70percent to 100percent, but only G2 and G7 were considered protected. G1, G3, G5 and G8 showed typical clinical signs of Newcastle disease. The Mycoplasma gallisepticum vaccines couldn't improve the response to Newcastle disease inactivated vaccine. The results suggest that Mycoplasma gallisepticum vaccination is immunosuppressive rather than immunomodulatory in Newcastle disease vaccination(AU)

En el presente trabajo se registró el impacto de la utilización de vacunas contra Mycoplasma gallisepticum sobre la respuesta posvacunal y la protección frente al reto con el virus de la enfermedad de Newcastle. Pollos libres de patógenos específicos se distribuyeron en ocho grupos de cuarenta pollos cada uno. El grupo G1 se vacunó con vacunas vivas atenuadas e inactivadas contra Mycoplasma gallisepticum. Al grupo G2 se le aplicaron las vacunas: viva atenuada contra Mycoplasma gallisepticum, inactivada contra Mycoplasma gallisepticum e inactivada contra la enfermedad de Newcastle. El grupo G3 se inmunizó con la vacuna viva atenuada contra Mycoplasma gallisepticum; el G4, con las vivas atenuadas contra Mycoplasma gallisepticum e inactivada contra la enfermedad de Newcastle; el G5, con la vacuna inactivada contra Mycoplasma gallisepticum; el G6 con las vacunas inactivadas contra Mycoplasma gallisepticum y la enfermedad de Newcastle; el G7, con la vacuna inactivada contra la enfermedad de Newcastle y el G8 se mantuvo como control no vacunado. Se midieron los anticuerpos de inhibición de la hemaglutinación contra el virus de la enfermedad de Newcastle y los porcentajes de mortalidad. El grupo G7 registró el mejor título de anticuerpos inhibidores de la hemaglutinación contra la enfermedad de Newcastle (7 log2). El grupo G2 registró un título de anticuerpos marginalmente satisfactorio (6 log2) tras la vacunación con las tres vacunas ensayadas. Los demás grupos revelaron títulos insatisfactorios que oscilaban entre 0 y 5. Los niveles de protección de los grupos G2, G4, G6 y G7 oscilaron entre el 70 por ciento y el 100 por ciento, pero sólo G2 y G7 se consideraron protegidos. Los grupos G1, G3, G5 y G8 mostraron signos clínicos típicos de la enfermedad de Newcastle. Las vacunas contra Mycoplasma gallisepticum no pudieron mejorar la respuesta a la vacuna inactivada contra la enfermedad de Newcastle. Los resultados revelan que la vacunación con Mycoplasma gallisepticum es más inmunosupresora que inmunomoduladora en la vacunación contra la enfermedad de Newcastle(AU)

Poor Respiratory Health Following Relapsing SARS-CoV-2 Infection in Children with Cystic Fibrosis

Children with cystic fbrosis (CF) constitute a high-risk group for COVID-19 with underlying chronic lung disease. COVID19 severity varying from mild infection to need of intensive care has been described in children with CF. Two children with signifcant underlying pulmonary morbidity are described here, who developed severe disease following SARS-CoV-2 infection. Case 1 (a 9-y-old boy) had pneumonia with respiratory failure requiring noninvasive ventilation support. He had delayed clearance of SARS-CoV-2, with recurrence of symptomatic disease with short asymptomatic period in between. He was also diagnosed with CF-related diabetes and allergic bronchopulmonary aspergillosis during the second episode. Case 2 (an 18-mo-old boy) had two episodes of SARS-CoV-2–related severe lower respiratory infection within a period of 2 mo, requiring high-fow nasal oxygen support. Both children had 3rd pulmonary exacerbation but SARS-CoV-2 was not detected in respiratory secretions. To conclude, children with CF with underlying pulmonary morbidity, can develop severe COVID-19 and prolonged SARS-CoV-2 shedding.

Prolonged SARS-CoV-2 RNA shedding in a young man recovering from traumatic pneumothorax

We describe a case of prolonged SARS-CoV-2 RNA shedding in an HIV-negative 21-year-old man recovering from abdominal and thoracic trauma. Nasopharyngeal (NP) swabs collected at 12 time points over a 95-day span all tested positive for SARS-CoV-2 by reverse transcription polymerase chain reaction (RT-PCR). Genotyping revealed canonical beta-variant E484K and N501Y mutations at earlier time points. Human rhinovirus, coronavirus NL63 and respiratory syncytial virus B were detected at different time points by RT-PCR. Full blood analysis at time point 9 (day 82) showed leukopenia with lymphocytosis. The patient's NP swab tested negative for SARS-CoV-2 by RT-PCR 101 days after the first positive test. The prolonged duration of SARS-CoV-2 RNA shedding in the context of trauma presented here is unique and has important implications for COVID-19 diagnosis, management and policy guidelines

Tiempo de excreción fecal de Escherichia coliproductora de toxina Shiga en niños con síndrome urémico hemolítico / Duration of fecal shedding of Shiga toxin-producing Escherichia coli among children with hemolytic uremic syndrome

Introducción. Conocer el tiempo de excreción fecal de Escherichia coli productora de toxina Shiga (Shiga toxin-producing Escherichia coli; STEC, por sus siglas en inglés) en pacientes con síndrome urémico hemolítico sería útil para controlar la transmisión de la enfermedad.Objetivos. 1) Analizar las características del tiempo de excreción de STEC. 2) Evaluar la asociación con las variables sexo, edad, necesidad de diálisis, antibióticos y serotipos de STEC.Población y métodos. Estudio prospectivo, observacional, longitudinal y analítico. Período 2013-2019. Se realizaron coprocultivos al ingresar y cada 5-7 días hasta obtener 2 negativos. Se definió tiempo de excreción desde el inicio de la diarrea hasta el primer negativo. Se confirmó STEC por detección de los genes stx1, stx2 y rfbO157 por reacción en cadena de la polimerasa. Se calculó la media (IC 95 %) y percentilos del tiempo de excreción de STEC, y se compararon las variables estudiadas mediante el test de t.Resultados. Se incluyeron 43 pacientes. La media de tiempo de excreción fue 10,2 días (IC 95 %: 8,92-11,59), rango: 3-22 días. El 90 % de los pacientes negativizaron el coprocultivo a los 15 días. No hubo diferencias según sexo (p = 0,419), edad (p = 0,937), necesidad de diálisis (p = 0,917), antibióticos (p = 0,147) ni serotipos (p = 0,231).Conclusión. El 90 % de los pacientes negativizó el coprocultivo a los 15 días del inicio de la diarrea, y todos, al día 22. No se encontró asociación entre el tiempo de excreción y las variables estudiadas.

Introduction. Knowing the duration of fecal shedding of Shiga toxin-producing Escherichia coli(STEC) among patients with hemolytic uremic syndrome would be useful to control disease transmission.Objectives. 1) To analyze the characteristics of STEC shedding duration. 2) To assess the association with sex, age, need of dialysis, antibiotics, and STEC serotypes.Population and methods. Prospective, observational, longitudinal, and analytical study in the 2013-2019 period. Stool cultures were done upon admission and every 5-7 days until 2 negative results were obtained. Shedding duration was defined as the period from diarrhea onset to the first negative result. STEC was confirmed with polymerase chain reaction detection of stx1, stx2, and rfbO157 genes. The mean (95 % CI) and percentile values of the STEC shedding duration were estimated, and the studied outcome measures were compared using the t test.Results. A total of 43 patients were included. The mean duration of shedding was 10.2 days (95 % CI: 8.92-11.59), range: 3-22 days. After 15 days, 90 % of patients had a negative stool culture. There were no differences in terms of sex (p = 0.419), age (p = 0.937), need of dialysis (p = 0.917), antibiotics (p = 0.147) or serotype (p = 0.231).Conclusion. Fifteen days after the onset of diarrhea, 90 % of patients had a negative stool culture, and all patients had one after 22 days. No association was observed between the duration of shedding and studied outcome measures.

Viral shedding in day-care children and students infected with norovirus in outbreaks / 上海预防医学

Objective:This study aimed to investigate the time duration of norovirus shedding among day-care children and students during norovirus outbreaks， as well as influencing factors affecting the viral shedding. Methods:Suspected cases of norovirus infection and their close contacts were collected from child care and school settings during norovirus outbreaks in Xuhui District， Shanghai， from 2017 through 2019. Specimens were detected using real-time RT-PCR to determine whether children had been infected with norovirus. Subsequently， further specimens were collected every 3-7 days from infected children until specimens tested negative for norovirus. Results:A total of 76 outbreaks were reported involving 1 014 suspected cases. In the 421 suspected cases， 311 confirmed cases were diagnosed after examination. Furthermore， a total of 58 confirmed cases participated in this study with informed consent， with a participation rate of 18.65%. The average time duration of norovirus shedding was （16.24±13.80） days， in which 79.31% had viral shedding more than 7 days， 37.93% more than 14 days and 17.24% more than 21 days. A Cox proportional-hazards model showed that children with more severe symptoms （HR=2.06，P=0.040）， day-care children （HR=4.13，P=0.012）， and confirmed cases in 2019 （HR=0.11，P<0.001） had longer duration of viral shedding. Conclusion:Children may remain shedding norovirus after their recovery and back to class. Improvement in sanitation for these recovered children in child care and schools is especially necessary， which may avert secondary transmission.

Development and validation of an individualized nomogram for early prediction of the duration of SARS-CoV-2 shedding in COVID-19 patients with non-severe disease / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

With the number of cases of coronavirus disease-2019 (COVID-19) increasing rapidly, the World Health Organization (WHO) has recommended that patients with mild or moderate symptoms could be released from quarantine without nucleic acid retesting, and self-isolate in the community. This may pose a potential virus transmission risk. We aimed to develop a nomogram to predict the duration of viral shedding for individual COVID-19 patients. This retrospective multicentric study enrolled 135 patients as a training cohort and 102 patients as a validation cohort. Significant factors associated with the duration of viral shedding were identified by multivariate Cox modeling in the training cohort and combined to develop a nomogram to predict the probability of viral shedding at 9, 13, 17, and 21 d after admission. The nomogram was validated in the validation cohort and evaluated by concordance index (C-index), area under the curve (AUC), and calibration curve. A higher absolute lymphocyte count (

Factors associated with prolonged duration of viral clearance in non-severe SARS-CoV-2 patients in Osaka, Japan

BACKGROUND@#We investigated factors associated with prolonged viral clearance of SARS-CoV-2 among non-severe adult patients in Osaka, Japan. A total of 706 laboratory-confirmed COVID-19 patients were enrolled in this longitudinal observational study between 29 January 2020 and 31 May 2020, across 62 hospitals and three non-hospital recuperation facilities.@*METHODS@#Logistic regression analysis was performed to investigate the factors associated with prolonged (29 days: upper 25% in duration) viral clearance of SARS-CoV-2. Linear regression analysis was conducted to assess these factors 14 days after symptom onset.@*RESULTS@#The median duration of viral clearance was 22 days from symptom onset. After adjustment for sex, age, symptoms, comorbidity, and location of recuperation, comorbidities were associated with prolonged duration: (OR, 1.77 [95% CI, 1.11-2.82]) for one, (OR, 2.47 [95% CI, 1.32-4.61]) for two or more comorbidities. Viral clearance 14 days after symptom onset was 3 days longer for one comorbidity and 4 days longer for two or more comorbidities compared to clearance when there was no comorbidity.@*CONCLUSION@#The presence of comorbidity was a robust factor associated with a longer duration of viral clearance, extending by 3 to 4 days compared to patients with no comorbidity.

SARS-CoV-2 nucleic acid shedding is variable for every person

Abstract INTRODUCTION: Considering the persistent positivity on RT-qPCR tests, the results of SARS-CoV-2 were monitored to evaluate the viral RNA shedding period. METHODS: Between March and June 2020, the sequential results of 29 healthcare workers' were monitored using RT-qPCR. RESULTS: More than 50% of the individuals remained RT-qPCR positive after 14 days. Furthermore, this is the first study to describe positive RT-qPCR for SARS-CoV-2 in a healthcare worker with mild symptoms 95 days after the first positive test. CONCLUSIONS: Sequential RT-qPCR results were heterogeneous, and the viral RNA shedding period is unique for each person.

A controlled study of the effects of laparoscopic radical resection of colon cancer on the shedding of peritoneal and intestinal cancer cells and peritoneal fibrinolysis in patients with locally advanced colon cancer / 中国医师进修杂志

Objective:To investigate the effect of laparoscopic radical resection of colon cancer on the shedding of cancer cells in the abdominal cavity and intestinal cavity and peritoneal fibrinolysis in patients with locally advanced colon cancer, to provide a reference for treatment.Methods:From March 2018 to May 2020, 76 patients with locally advanced colon cancer in Wanbei Coal and Electricity Group General Hospital were selected and divided into group A (33 patients) and group B (43 patients) according to different treatment procedures. Group A underwent laparoscopic radical resection of colon cancer, group B underwent open radical resection of colon cancer. The related indexes, complications, and serum immune function indexes (CD 4+, CD 8+, CD 4+/CD 8+) before operation and 1 d and 3 d after operation, peritoneal fibrinolytic function indexes of the peritoneal tissue: peritoneal tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), the positive rate of peritoneal cancer cell shedding at the beginning of the operation and immediately after the operation, the positive rates of intestinal cancer cell shedding before and immediately after surgery were compared between the two groups. Results:Although the operation time of group A was longer than that of group B: (186.21 ± 24.07) min vs. (149.49 ± 17.82) min, the postoperative anal exhaust time and hospital stay were shorter than those of group B: (3.32 ± 0.75) d vs. (3.84 ± 1.02) d, (10.62 ± 1.74) d vs. (12.85 ± 2.26) d, and the amount of intraoperative blood loss was less than that of group B: (102.08 ± 16.39) ml vs. (159.50 ± 23.14) ml, the differences were statistically significant ( P<0.05). The complication rate of group A was lower than that of group B: 9.09% (3/33) vs. 27.91%(12/43)( P<0.05). Serum CD 4+, CD 8+, CD 4+/CD 8+ levels in the two groups at 1 and 3 days after operation were lower than those before the operation, but those in group A were higher than those in group B ( P<0.05). The t-PA level of the peritoneal tissue immediately after the operation in the two groups was lower than that at the beginning of the operation, but that in group A was higher than that in group B. The level of PAI-1 was higher than that at the beginning of the operation, but the level of PAI-1 in group A was lower than group B ( P<0.05). There was no significant difference in the positive rate of cancer cells in the abdominal cavity and intestinal cavity at each time point in the two groups ( P>0.05). Conclusions:Application of laparoscopic radical resection of colon cancer for locally advanced colon cancer can reduce surgical trauma, promote postoperative recovery, reduce complications, reduce the impact on the body′s immune function and peritoneal fibrinolytic function, and does not increase the risk of shedding cancer cells in the abdominal cavity and intestinal cavity after surgery.

Eliminación de huevos de los pequeños estróngilos en la materia fecal de los equinos y su importancia práctica en la posibilidad de tratamientos selectivos / Fecal shedding of equine small strongyle eggs and its practical importance for selective treatment

Resumen Los pequeños estróngilos son los parásitos de mayor prevalencia e importancia en los equinos de todo el mundo, y el desarrollo generalizado de la resistencia de estos nematodos a los antihelmínticos está impulsando la aplicación de tratamientos selectivos (TS) para disminuir o demorar el desarrollo de estos fenómenos. Esta estrategia se basa en conteos de huevos de nematodos en la materia fecal de todos los integrantes del grupo animal para tratar solamente aquellos que sobrepasan un determinado umbral o cut off. Este principio de TS se ve favorecido por la consistencia de los conteos de huevos por gramo de heces (hpg) en los equinos y está siendo empleada en algunos países del hemisferio norte, especialmente en los animales adultos. En la Argentina, existe una ausencia de información básica en relación a las condiciones climáticas, de pastoreo y manejo que podrían resultar en cargas parasitarias y transmisión de nematodos diferentes a las observadas en el hemisferio norte. En este contexto, el objetivo de este estudio fue caracterizar la eliminación de huevos de pequeños estróngilos en 436 equinos de diferentes edades pertenecientes a 19 establecimientos del área central de la Argentina. El 90% de los equinos mostró huevos de estróngilos en las heces y los valores de hpg fueron menores a 200 y mayores a 1.000 en el 32% y 22% de los equinos respectivamente. La distribución de los huevos de estróngilos entre individuos de todas las edades fue sobre-dispersa o agregada, con una media aritmética general de 671,59 ± 789,76 y un valor de k o parámetro de agregación inversa de 0,72 (distribución de la binomial negativa). La edad de los animales (potrillos vs adultos) y los biotipos (deportivo vs trabajo) en la categoría adultos influenciaron la magnitud de los valores del hpg (p<0,001). En esta última categoría el 35% de los animales fue responsable de la excreción de aproximadamente el 80% de los huevos eliminados en las pasturas. Si bien existen algunas diferencias con lo observado en países del hemisferio norte con poblaciones parasitarias más agregadas o sobre-dispersas, los TS para el control de los pequeños estróngilos en equinos adultos podrían también ser una estrategia válida bajo nuestras condiciones para disminuir la presión de selección sobre el genoma parasitario y permitir el desarrollo de poblaciones en refugio.

Abstract Small strongyles are the most prevalent and important parasites in grazing horses throughout the world and the widespread development of antihelminthic resistance has prompted in some countries of the northern hemisphere the application of selective treatments (ST) to reduce or delay the development of these phenomena. This strategy is based on determining strongyle fecal egg counts of all herd members and treating only those exceeding a certain threshold or cut off. However, there is an absence of basic information on horses maintained under climatic, grazing or management conditions different from those observed in the northern hemisphere. In this context, the aim of this study was to characterize the elimination of eggs of small strongyles in horses of different ages from 19 farms in the central area of Argentina. Out of a total of 436 horses, 90% showed positive strongyles egg counts and in these animals the count of eggs per gram of feces (epg) was under 200 and over 1,000 in 32% and 22% of the horses respectively. The distribution of strongyle eggs among individuals of all categories was over-dispersed or aggregated with a general epg arithmetic mean of 671.59 ± 789.76 and a value of the inverse aggregation parameter of 0.72 (negative binomial distribution). The age of the animals (foals vs. adults) and the biotypes in the adult category (sports vs. work) influenced the magnitude of the epg values (P <0.001). In the latter category, approximately 35% of the animals were responsible for the excretion of approximately 80% of the eggs in the pastures. Although some differences on magnitude and distribution of strongyle fecal egg counts were observed in countries of the northern hemisphere, ST of small strongyles in adult equines could also be a valid strategy under Argentinian conditions to reduce the selection pressure on the parasitic genome and allow the development of refugia populations.

Clinical observation on monitoring different body parts of neonatal intensive care unit critically ill newborns by percutaneous oxygen partial pressure and carbon dioxide partial pressure / 中国实用护理杂志

Objectives@#Study on the accuracy and influencing factors of neonatal intensive care unit (NICU) critically ill newborns different body parts monitoring by percutaneous oxygen partial pressure (TcpO2) and carbon dioxide partial pressure (TcpCO2), in order to provide a basis for non-invasive monitoring of critically ill newborns in ICU.@*Methods@#60 cases of critically ill newborns requiring blood gas analysis were selected as research cases during July 2017 to March 2018 in Wuxi City Maternity and Child Hospital Neonatology. According to the randomized control principle, three groups were divided, chest group (20 cases), abdomen group (20 cases), leg group (20 cases). The chest group placed the electrodes of the transcutaneous gas analyzer on newborns′ anterior chest. The abdomen group placed the electrodes on newborns′ abdomen. And the leg group placed the electrodes on the inner thigh. PaO2 and PaCO2 values were collected from the blood gas results of critically ill newborns. TcpO2 and TcpCO2 values were recorded. And at the same time, the electrode shedding situation was observed as well. Compare transcutaneous data and arterial blood data, and do analysis.@*Result@#The chest group TcpO2 (69.05±9.17) mmHg(1 mmHg=0.133 kPa), TcpCO2 (46.9±10.57) mmHg, PaO2 (76.4±8.64) mmHg, PaCO2 (40.65±4.74) mmHg, the PaO2 and PaCO2 values were obviously different from the blood gas analysis results (t=-2.608, 2.413, P<0.05). The abdomen group and the leg group had no significant differences (P>0.05) . And the electrode sheet shedding rate was 30% in the chest group, 25% in the abdomen group, and 10% in the leg group, the three groups had no significant differences (χ2=2.553, P>0.05) .@*Conclusion@#NICU critically ill newborns thigh skin monitoring by percutaneous oxygen partial pressure and carbon dioxide partial pressure has high accuracy, and the electrode sheet shedding rate is relatively low. Therefore, it is a safe and effective clinical monitoring method, of great significance for monitoring changes in the condition of critically ill newborns.

A Study on Factors Associated with Duration of Influenza Virus Shedding in Children / 계명의대학술지

To prevent the spread of influenza among infants and adolescents attending kindergartens and schools, proper quarantining of those who are ill is necessary. In this study, the rapid antigen test (RAT) was performed in patients to investigate the factors affecting the duration of virus shedding. The study included pediatric patients who were diagnosed with influenza by RAT at Daedong Hospital between November 2016 and April 2019. We identified the influenza subtype, age, gender, fever duration, oseltamivir medications, and time gap between fever subsided and RAT examination through chart review. A total of 330 patients were examined at discharge. The average age for RAT positive and negative patients was 6.32 ± 4.26 years and 8.47 ± 4.54 years, respectively. The average duration of fever for the RAT positive patients was 3.84 ± 1.09 days, and for those who were RAT negative was 4.191 ± 1.39. The average number of doses oseltamivir for RAT positive and negative patients was 7.68 ± 1.57 and 8.72 ± 1.37, respectively. The RAT was performed 24 to 48 hours after fever subsided (TG 24–48H group). At this time, 60 patients were positive and the rate of positive expression was 55.56%. Of the TG 48–72H group, 36 patients (26.09%) were positive. Of the TG 72–96H group, 18 patients (21.43%) were positive. Age, fever duration, number of doses oseltamivir and time gap after fever subsided were the factors that influenced the duration of influenza virus shedding. These factors should be considered during the quarantining influenza patients.

Study on shedding particles from Chuanping Sustained-release Tablets based on multi-marker components balanced release / 中草药

Objective: To study on the changes of shedding particles, drug loading and release of Chuanping Sustained-release Tablets (CST) which were made by the different sustained-release excipients in vitro, so as to elucidate the mechanism about balanced release of multi-marker components on Chinese materia medica compound sustained-release preparation. Methods: Using Chuanping Prescription (Ephedra Herba and Datura Flos) as model drug, improved Peach Gum and HPMC was used as sustained release materials, the release test combinied with underwater video observation were applied to shot external forms at different time point, and the laser particle sizer was applied to determinate particle size, and HPLC was applied to determine the accumulated release rate of the index components (ephedrine, pseudoephedrine, and scopolamine) to calculate the cumulative release curve slope K value, and to evaluate the balance release of the different components. Results: CST which were made by the improved peach gum and HPMC sustained-release excipient, which particles were dropped at 0.5 h after contacting the dissolution medium. At the same time, the particles were obviously shedding with the passage of time. In contrast, CST that was made by the improved peach gum, its balanced release of multi-marker components was better (K of ephedrine was 12.18, K of pseudoephedrine was 12.30, and K of scopolamine was 12.40), and particles dropped faster (it was significantly at 1 h), and particle size was bigger (D50 was 53.37—70.33 μm and D90 was 100.3—196.5 μm), and drug loading was more (ephedrine 30.63%, pseudoephedrine 32.97%, and scopolamine 31.67%), and release time of drug was longer (60—120 min). Conclusion: The shedding particles were important part of balance release of multi-marker components about CST which was made by the improved peach gum sustained-release excipient, and also was the embodiment of the drug release mode of “corrosion-dissolution”.

Clinical observation on monitoring different body parts of neonatal intensive care unit critically ill newborns by percutaneous oxygen partial pressure and carbon dioxide partial pressure / 中国实用护理杂志

Objectives Study on the accuracy and influencing factors of neonatal intensive care unit (NICU) critically ill newborns different body parts monitoring by percutaneous oxygen partial pressure (TcpO2) and carbon dioxide partial pressure (TcpCO2), in order to provide a basis for non-invasive monitoring of critically ill newborns in ICU. Methods 60 cases of critically ill newborns requiring blood gas analysis were selected as research cases during July 2017 to March 2018 in Wuxi City Maternity and Child Hospital Neonatology. According to the randomized control principle, three groups were divided, chest group (20 cases), abdomen group (20 cases), leg group (20 cases). The chest group placed the electrodes of the transcutaneous gas analyzer on newborns′anterior chest. The abdomen group placed the electrodes on newborns′ abdomen. And the leg group placed the electrodes on the inner thigh. PaO2 and PaCO2 values were collected from the blood gas results of critically ill newborns. TcpO2 and TcpCO2 values were recorded. And at the same time, the electrode shedding situation was observed as well. Compare transcutaneous data and arterial blood data, and do analysis. Result The chest group TcpO2(69.05 ± 9.17)mmHg(1 mmHg=0.133 kPa), TcpCO2( 46.9±10.57)mmHg, PaO(276.4±8.64)mmHg, PaCO(240.65± 4.74)mmHg, the PaO2 and PaCO2 values were obviously different from the blood gas analysis results (t=-2.608, 2.413, P<0.05). The abdomen group and the leg group had no significant differences(P>0.05). And the electrode sheet shedding rate was 30% in the chest group, 25% in the abdomen group, and 10% in the leg group, the three groups had no significant differences(χ2=2.553,P>0.05). Conclusion NICU critically ill newborns thigh skin monitoring by percutaneous oxygen partial pressure and carbon dioxide partial pressure has high accuracy, and the electrode sheet shedding rate is relatively low. Therefore, it is a safe and effective clinical monitoring method, of great significance for monitoring changes in the condition of critically ill newborns.

Detection of Listeria spp. in cattle and environment of pasture-based dairy farms / Detecção de Listeria spp. em gados leiteiros no meio ambiente com base na pastagem

The aim of the study was to detect Listeria spp., particularly Listeria monocytogenes, in cattle and environment of pasture based dairy farms in Paysandú, Uruguay. A two-stage sampling was conducted, 10 farms were selected by probability proportional to size. A single visit was made to each farm. Samples from bovine faeces, feedstuffs, bulk tank milk, drinking water and soil from the entry and exit pens of the milking parlour were collected for bacteriological studies. PCR assays were used to confirm species and determine the serotype profile of L. monocytogenes isolates. AscI-pulsed-field gel electrophoresis was done to genetically compare them. Listeria spp. were isolated from eight of ten dairy farms, whereas L. monocytogenes in three of them. Serotype distribution in L. monocytogenes was as follows: 1/2a, three isolates; 4b, one isolate. L. monocytogenes or L. innocua excreted from clinically healthy milking cows was detected via faeces. In feedstuffs, only one L. monocytogenes 1/2a isolate from a pasture was obtained. The strain was identical by PFGE to an isolate 1/2a obtained from a pool of milking cow feces that grazed on this farm. No isolation of Listeria spp. was retrieved from the bulk tank milk or drinking water from any of the farms. Listeria innocua was detected in 13 feedstuffs and seven samples of soil from the entry and exit pens of the milking parlour. This is a first local study that confirms the presence of Listeria spp. including L. monocytogenes in healthy cattle and environment of pasture-based dairy farms. These results suggest the potential role that healthy cattle and their sub-products would play as a source of these agents for humans and/or others animals. More detailed studies that include genetic comparison of human and animal isolates are required in order to clearly establish the epidemiological relationship.(AU)

O objetivo deste trabalho foi detectar a presença de bactérias do gênero Listeria e particularmente Listeria monocytogenes, em bovinos leiteiros no ambiente de Paysandú, Uruguai. Foi realizada uma amostragem em duas etapas, dez estabelecimentos foram selecionados por probabilidade proporcional ao tamanho. Foi realizada uma única visita a cada propriedade. Foram coletadas amostras para cultura bacteriológica de matéria fecal bovina, além de alimentos, leite do tanque de resfriamento, água e solo na entrada e saída da sala de ordenha. Com os isolados de L. monocytogenes foi realizado PCR para a confirmação da espécie e determinação do perfil do serotipo. AscI-elctroforese em gel de campo pulsado foi realizado para compará-los geneticamente. Listeria spp. foram isoladas de oito de dez estabelecimentos, enquanto L. monocytogenes foram detectadas em três deles. A distribuição dos serotipos nos isolados de L. monocytogenes recuperados foi: 1/2a três isolados, 4b um isolado. Foram detectadas vacas leiteras clinicamente sadias ​​que excretaram L. monocytogenes ou L. innocua nas fezes. Dos alimentos do gado houve só um isolamento de L. monocytogenes 1/2a em uma pastagem. Esta estirpe foi idêntica no PFGE a um isolado 1/2a obtido de uma "piscina" de fezes de vacas leiteiras do mesmo estabelecimento. Não houve isolamento de Listeria no leite do tanque de resfriamento ou na água de nenhum dos estabelecimentos. Listeria innocua foi detectada em 13 alimentos para o gado e sete amostras de solo na entrada e saída da sala de ordenha. Este parece ser o primeiro estudo local que confirma a presença de Listeria spp. incluindo L. monocytogenes em vacas leiteiras sadias e no meio ambiente de propriedades leiteiras com base alimentícia na pastagem. Esses resultados sugerem o potencial de vacas sadias e seus subprodutos como possível fonte desses agentes para humanos e/ou outros animais. São necessários estudos mais detalhados que incluem a comparação genética de isolados humanos e de animais para estabelecer claramente seu relacionamento epidemiológico.(AU)

Study on biocompatibility of carbon-based composites / 生物医学工程学杂志

Silicon carbide (SiC) film and silicon dioxide (SiO ) film were deposited on the surface of carbon/carbon composite (C/C) by low pressure chemical vapor deposition (LPCVD). The biocompatibility of the three carbon-based composites, e. g. C/C, C/C-SiC, C/C-SiO were investigated by cytotoxicity test, cell direct contact and cell adhesion experiments. Cytotoxicity, cell direct contact and cell adhesion showed that the three materials had no toxic effect on mouse fibroblasts (L929 cells). However, the particles dropped off from the three materials had a great impact on evaluation accuracy of the thiazolyl blue (MTT) test. More the particles were lost, more growth inhibition to L929 cells. The evaluation accuracy of MTT method can be kept with the filtered extract of materials. Furthermore, the results of surface particles shedding experiment showed that the amount of surface particles shed from C/C-SiO was the most, followed by C/C and C/C-SiC in 72 hours. Particles shedding curves showed there was a peak reached at eighth hour and then declined to the thirty-sixth hour. The filtrate analysis showed that there was no ion exchange between the three materials and simulated body fluid (SBF) solution. The results of this study on biocompatibility of carbon-based composites have certain guiding significance for their future application in clinical filed.

Environmental drivers on leaf phenology of ironstone outcrops species under seasonal climate

ABSTRACT Banded iron formations (BIF) have a particular vegetation type and provide a good model system for testing theories related to leaf phenology, due to unique stressful environmental conditions. As a consequence of the stressful conditions of BIF environment, we hypothesize that most species would retain at least some significant canopy cover, even at the end of the dry season, independently of growth form - trees, shrubs, and sub-shrubs. Considering the strong seasonality, we also hypothesize that photoperiod and rainfall act as triggers for leaf fall and leaf flushing in these environments. The majority of the fifteen studied species had a semi-deciduous behavior and shed their leaves mainly during the dry season, with a recovery at the end of this season. In general, leaf flushing increased around the spring equinox (end of the dry season and start of the rainy season). A trade-off between leaf loss and leaf maintenance is expected in a community in which most plants are naturally selected to be semi-deciduous. Our results suggest photoperiod as a dominant factor in predicting leaf phenology.