SARS‐CoV‐2 lgM/lgG antibody detection confirms the infection after three negative nucleic acid detection

An ongoing outbreak of viral pneumonia was caused by a novel coronavirus in China in 2019. By March 19, over 200 thousand confirmed cases of SARS‐CoV‐2 infection and over 9000 deaths have been reported throughout the world. For this infectious disease, nucleic acid detection is still the gold standard for pathogenic detection. However, nucleic acid detection takes a long time and has relatively high "false negative"; therefore, we need urgently a convenient and accurate detection method to make up for this deficiency. In this article, we will show such technical characteristics of lgM/lgG serum antibody detection, compared with nucleic acid detection.     

四种杂交组合奥尼罗非鱼及其亲本的生长对比研究

通过RFID电子标记注射、跟踪和生长性状测量,对2个奥利亚罗非鱼品系(ZZ、AA)、2个尼罗罗非鱼品系(XX、EE)自交群体及其杂交奥尼罗非鱼4个群体(XZ、XA、EZ、EA)进行生长对比研究,罗非鱼亲本来自国家罗非鱼产业技术体系研发中心。结果表明:XZ、XA、EZ、EA四个奥尼罗非鱼群体雄性率均达94%以上,全长、体长、头长、体高等性状特征值显著高于亲本品系(P<0.05),奥尼罗非鱼的生长速率相对其亲本品系具有一定的优势,同时4个奥尼群体间生长性状特征值也存在显著差异(P<0.05);生长性状相关分析显示罗非鱼各配组群体的体质量与尾柄长相关性较低(0.690—0.846),与全长、体长、体高、体厚相关性较高;对罗非鱼各配组群体的比例性状进行主成分分析,第1主成分主要代表BS、HS、CDS、BWS性状特征,第2主成分主要代表TS、HS、CLS性状特征,通过第1、第2主成分作图可将AA与其他6个罗非鱼配组群体有效区分。     

医学微生物学课程思政改革的实践与思考

专业课程是课程思政建设的基本载体,课程思政建设是课程教学改革的根本任务.医学微生物学是医学生的一门专业基础课程,教学内容涉及与人民生活息息相关的病原微生物,实用性强.紧密结合医学微生物学课程内容和人民健康需求,开展课程思政教育资源体系建设,强化学生知识学习和思想教育,达到"立德树人"的培养目标.文章介绍了围绕医学微生物...     

Aspects of the bionomics of Phlebotomus sergenti sandflies from an endemic area of anthroponotic cutaneous leishmaniasis in Aleppo Governorate, Syria

Aspects of the bionomics of phlebotomine sandflies (Diptera: Psychodidae) were studied from June to November 2005 in three foci of anthroponotic cutaneous leishmaniasis (ACL) in Aleppo Governorate, Syria, where the agent Leishmania tropica (Wright) (Kinetoplastida: Trypanosomatidae) is transmitted by Phlebotomus sergenti Parrot. Syria has been designated by the World Health Organization as one of four countries in the Old World where cutaneous leishmaniasis is hyperendemic, but little is known about the biology of local vector populations. Standard collections by sticky traps showed two peaks in density, in June and late August. In total, 1840 sandflies were caught, comprising five species: Phlebotomus papatasi (Scopoli) (68.0%); P. sergenti (25.4%); Sergentomyia minuta (Rondani) (6.4%); Phlebotomus tobbi Adler & Theodor (0.1%), and Phlebotomus mascittii canaaniticus Adler & Theodor (0.1%). Similar numbers of P. sergenti were caught indoors (246 specimens) and outdoors (222), whereas P. papatasi was significantly more abundant indoors (1096 specimens) than outdoors (156) (χ² = 241, P < 0.01). In total, 212 blood-fed females were tested for host blood determination, of which 176 (83.0%) reacted with anti-species reagent. Results from 20 P. sergenti suggest that this species is an opportunistic feeder, imbibing human, ovine, avian, bovine and feline blood, although more bloodmeals were taken from humans and cattle than expected in relation to the relative proportions of potential hosts present (the forage ratio, FR). The bionomics of P. sergenti are discussed in relation to the inefficacy of control campaigns based on indoor spraying with residual insecticides that have been implemented by the Syrian Ministry of Health to control the epidemics of ACL in the Aleppo Governorate.     

Processing of newly synthesized cachectin/tumor necrosis factor in endotoxin-stimulated macrophages

The biosynthesis and processing of cachetin/tumor necrosis-factor (TNF) were examined in the murine macrophage-like cell line RAW 264.7. Lipopolysaccharide-stimulated cells secreted both glycosylated and nonglycosylated 17-kilodalton (kDa) mature cachectin/TNF into the culture medium. Secreted cachectin/TNF was derived from membrane-associated precursors that were precipitated by polyclonal antisera raised against either the mature protein or synthetic peptide fragments of the 79 amino acid cachectin/TNF prohormone sequence. About half of the precursors were N-glycosylated, apparently cotranslationally. The cachectin/TNF precursors were then proteolytically cleaved to release soluble mature cytokine into the medium, while the membrane-bound 14-kDa presequence remained cell associated. During the period of LPS stimulation, the amount of macrophage cell surface cachectin/TNF remained at a low level, suggesting that both nonglycosylated and glycosylated precursors of cachectin/TNF are efficiently cleaved by these cells. These findings suggest the presence of a unique mechanism for the secretion of cachectin/TNF.     

Risk prediction with imperfect survival outcome information from electronic health records

Readily available proxies for the time of disease onset such as the time of the first diagnostic code can lead to substantial risk prediction error if performing analyses based on poor proxies. Due to the lack of detailed documentation and labor intensiveness of manual annotation, it is often only feasible to ascertain for a small subset the current status of the disease by a follow-up time rather than the exact time. In this paper, we aim to develop risk prediction models for the onset time efficiently leveraging both a small number of labels on the current status and a large number of unlabeled observations on imperfect proxies. Under a semiparametric transformation model for onset and a highly flexible measurement error model for proxy onset time, we propose the semisupervised risk prediction method by combining information from proxies and limited labels efficiently. From an initially estimator solely based on the labeled subset, we perform a one-step correction with the full data augmenting against a mean zero rank correlation score derived from the proxies. We establish the consistency and asymptotic normality of the proposed semisupervised estimator and provide a resampling procedure for interval estimation. Simulation studies demonstrate that the proposed estimator performs well in a finite sample. We illustrate the proposed estimator by developing a genetic risk prediction model for obesity using data from Mass General Brigham Healthcare Biobank.     

Performance of polyvoltine silkworm Bombyx mori L. on different mulberry plant varieties

Five cultivated mulberry plant varieties, BSRM‐34, BSRM‐56, BSRM‐57, BSRM‐58 and BSRM‐59, were used to evaluate the effects of plant variety on larval and cocoon characteristics of mulberry silkworm Bombyx mori L. Silkworm larvae undergo their entire larval periods on leaves of mulberry varieties. Different larval characteristics of larval weight, larval length and larval breadth were measured in different growth stages. After rearing, the fifth instar larvae were transferred into a mountage (Chandraki) structure for cocoon rearing for spinning and cocoon production. The cocoons were then harvested and different cocoon characteristics like cocoon weight, shell weight and shell percentage; and other characters like pupal weight and effective rate of rearing were measured. The results showed statistically significant differences among different varieties on larval and cocoon characteristics. The highest performance was observed by feeding the variety BSRM‐34 in respect of the average weight of 10 mature larvae (40.5 g), single mature larval length (7.6 cm) and breadth (1.0 cm), single cocoon weight (1.4 g), shell weight (0.2 g) and pupal weight (1.2 g) while the average performance was recorded by feeding varieties BSRM‐57 and BSRM‐59. The poorest performance was showed by feeding the variety BSRM‐56 (in case of larval characters) and BSRM‐58 (in case of cocoon characteristics). These two varieties also showed the poorest performance for silk yield. Through comparing all the above parameters it was concluded that BSRM‐34 is the best mulberry variety and it is recommended that Bangladeshi farmers adopt that variety for better yield of silk.     

In vitro development of the strobilar stage of Mesocestoides corti

Thompson R. C. A., Jue Sue L. P. and Buckley S. J. 1982. In vitro development of the strobilar stage of Mesocestoides corti. International Journal for Parasitology12: 303–314. Sexually mature strobilated adults of Mesocestoides corti were grown consistently from undifferentiated tetrathyridia in vitro using a conventional diphasic culture system. Development (growth, strobilisation and maturation) was compared in vitro and in vivo. Although growth and strobilisation were comparable in vitro and in vivo, during the first 18 days, total length and numbers of proglottids decreased in vivo but continued to increase in vitro after day 18. Both male and female reproductive systems appeared to develop normally in vitro and self copulation was frequently observed in cultured worms. However, fully developed oncospheres were not produced in vitro.