Plasma lipoprotein abnormalities associated with acquired hepatic triglyceride lipase deficiency

Two enzymes, lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL), are released into human plasma after intravenous injection of heparin. LPL is the major enzyme responsible for initiating catabolism of chylomicrons and very-low-density lipoproteins (VLDL). The physiological role of HTGL is less certain. HTGL has been postulated to be an alternate enzyme to LPL in hydrolysis of triglyceride in VLDL and to be an important enzyme for removal of phospholipid from both low-density lipoproteins (LDL) and high-density lipoproteins (HDL). In this latter role, this enzyme would convert larger, lighter lipoprotein particles to smaller denser particles. HTGL deficiency has been found in severe liver disease and with a genetic deficiency of this enzyme. A unique patient is described with acquired hepatic triglyceride lipase deficiency and vitamin A intoxication. This patient developed hypercholesterolemia with an increase in both LDL and HDL. An increased proportion of lighter LDL (LDL1) and HDL (HDL2) was noted. In addition, after administration of heparin there was no shift in the distribution of apoE in plasma fractionated using a column containing 4% agarose. These findings are consistent with a postulated role of HTGL in metabolism of light LDL and HDL particles and some classes of apoE containing lipoproteins.     

Respiratory virus infections in transplant recipients after reduced-intensity conditioning with Campath-1H: high incidence but low mortality

Respiratory virus infections can cause serious morbidity and mortality after conventional allogeneic stem cell transplantation. However, the incidence and outcome of these infections after reduced intensity conditioning has not been reported. Between 1997 and 2001, 35 episodes of respiratory virus infections were noted in 25 of 83 transplant recipients conditioned with fludarabine, melphalan and Campath-1H, and 80% of them received early antiviral therapy. Parainfluenza virus (PIV) 3 was the commonest isolate (45.7%) followed by respiratory syncytial virus (37%). Patients with myeloma were more susceptible to these infections [odds ratio (OR) 4.1, P = 0.01] which were often recurrent in patients with severe acute or chronic graft-versus-host disease (GVHD) (OR 10.6, P = 0.03). Infection within the first 100 d (OR 5.0, P = 0.05) and PIV 3 (OR 9.2, P = 0.01) isolation were risk factors for developing lower respiratory infection. Although more than half of the episodes progressed to lower respiratory infection, the mortality was only 8%. This could have been due to early initiation of antiviral therapy, but the attenuation of pulmonary damage due to the reduced-intensity conditioning, low incidence of GVHD and, paradoxically, the low CD4+ T-cell subset in this setting might also have been contributory factors.     

严重急性呼吸综合征传播影响因素病例对照研究

目的探讨严重急性呼吸综合征(SARS)传播的影响因素。方法采用病例对照研究,分别对有明确流行病学接触史的SARS患者与密切接触者,无明确流行病学接触史的SARS患者与一般人群进行比较。结果工作环境不通风、去公共场所无戴口罩的习惯、和患者接触时不通风与SARS呈正相关;疫情流行期间未到过医院,外出不采用人口密度相对较大的公交车、地铁等交通工具与SARS负相关。结论应加强医院建设和管理,以应对传染病的流行;当与患者接触时应注意通风;疫情暴发期间到公共场所应戴口罩;患者尽量减少到医院的机会和使用人口密度相对较大的交通工具。     

Measurement of maximal inspiratory pressure in ventilated children

Maximal inspiratory pressure (PIMAX), the maximum negative pressure generated during temporary occlusion of the airway, is commonly used to measure inspiratory muscle strength in mechanically ventilated infants and children. There are, however, no guidelines as to how the PIMAX measurement should be made. We compared the maximum inspiratory pressure generated during airway occlusion (PIMAX(OCC)) to that when a unidirectional valve (PIMAX(UNI)), which allowed expiration, but not inspiration was used. Twenty-two mechanically ventilated children (mean (SD) age 4.8 (4.5) years) were studied. Three sets of end expiratory occlusions were performed for each method in random order. The expired volume during PIMAX(UNI) was assessed and related to the functional residual capacity (FRC) measured using a helium dilution technique.The mean (SD) PIMAX(UNI) (45.5 (15.2) cmH(2)O) was significantly greater than mean (SD) PIMAX(OCC) (30.9 (9.0) cmH(2)O) (P < 0.0001). The mean (SD) expired volume during PIMAX(UNI), was 98 ml (62.3), a mean reduction in FRC of 33.1% (SD 13.9). There were no significant differences between techniques in the baseline respiratory drive, the number of efforts required and the time to reach PIMAX. Regardless of technique, PIMAX was reached in 10 inspiratory efforts or 15 sec of airway occlusion.A unidirectional valve allowing expiration, but not inspiration yields greater PIMAX values in children. Occlusions should be maintained for 12 sec or eight breaths (99% CI of mean).     

Expiratory-Synchronized Sleep in a Quadriplegic Patient Using Inspiratory Neck Muscles To Breathe

In a patient with C3 quadriplegia causing complete diaphragm paralysis who developed inspiratory neck muscles (INM) hypertrophy to sustain ventilation, spontaneous breathing deeply altered sleep architecture, relegating sleep to the expiratory phase of the ventilatory cycle. A polysomnographic recording performed during mechanical ventilation (without INM activity), showed that sleep was abnormal but unaffected by the respiratory cycle. During spontaneous breathing, the polygraphic recordings showed expiratory microsleep episodes, with inspiratory arousals synchronous to bursts of INM activity. This case report illustrates the powerful adaptability of the respiratory and sleep control systems to maintain each vital function.     

益生菌制剂对儿童反复呼吸道感染的疗效和免疫功能影响的系统评价

目的 系统评价益生菌制剂防治儿童反复呼吸道感染（RRTIs）的有效性和安全性,为临床提供循证参考。方法计算机检索PubMed、EMBase、Cochrane图书馆、中国生物医学文献数据库（CBM）、中国学术期刊全文数据库（CNKI）、维普中文期刊全文数据库（VIP）和万方数据库,收集益生菌制剂（试验组）防治儿童RRTIs的随机对照试验（RCT）,检索时限均为建库起至2019年3月。提取资料,用Rev Man 5.3软件进行Meta-分析。结果 共纳入12项研究,878例患者。Meta-分析结果显示,试验组在总有效率［RR=1.31,95%CI（1.22,1.41）,P<0.001］、抗菌药用药时间［MD=-4.42,95%CI（-5.92,-2.91）,P<0.001］、年呼吸道感染次数［MD=-2.30,95%CI（-2.70,-1.89）,P<0.001］、临床体征改善时间均优于对照组（P<0.05）;免疫球蛋白IgG ［MD=1.80,95%CI （1.60,2.01）,P<0.001］、IgA ［MD=0.37,95%CI（0.23,0.51）,P<0.001］、IgM［MD=0.06,95%CI（0.02,0.09）,P=0.002］,T淋巴细胞亚群CD3+［MD=4.48,95%CI（1.48,7.49）,P=0.03］、CD4⁺［MD=3.17,95%CI（1.01,5.55）,P=0.009］和CD8⁺［MD=-4.44,95%CI（-6.52,-2.36）,P<0.05］改善情况均显著优于对照组,差异均有统计学意义（P<0.05）。结论 益生菌可有效治疗儿童反复呼吸道感染,安全性较好。但由于纳入研究数量少,研究质量不统一,尚需要大样本、高质量的临床随机对照研究予以证实。     

Recent findings on the Coronavirus disease 2019 (COVID-19); immunopathogenesis and immunotherapeutics

Severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) is responsible for recent ongoing public health emergency in the world. Sharing structural and behavioral similarities with its ancestors [SARS and Middle East Respiratory Syndrome (MERS)], SARS-CoV-2 has lower fatality but faster transmission. We have gone through a long path to recognize SARS and MERS, therefore our knowledge regarding SARS-CoV-2 is not raw. Various responses of the immune system account for the wide spectrum of clinical manifestations in Coronavirus disease-2019 (COVID-19). Given the innate immune response as the front line of defense, it is immediately activated after the virus entry. Consequently, adaptive immune response is activated to eradicate the virus. However, this does not occur in every case and immune response is the main culprit causing the pathological manifestations of COVID-19. Lethal forms of the disease are correlated with inefficient and/or insufficient immune responses associated with cytokine storm. Current therapeutic approach for COVID-19 is in favor of suppressing extreme inflammatory responses, while maintaining the immune system alert and responsive against the virus. This could be contributing along with administration of antiviral drugs in such patients. Furthermore, supplementation with different compounds, such as vitamin D, has been tested to modulate the immune system responses. A thorough understanding of chronological events in COVID-19 contributing to the development of a highly efficient treatment has not figured out yet. This review focuses on the virus-immune system interaction as well as currently available and potential therapeutic approaches targeting immune system in the treatment of COVID-19 patients.     

新型冠状病毒肺炎病原体分离与鉴定

重症急性呼吸综合征冠状病毒2（severe acute respiratory syndrome coronavirus 2,SARS-CoV-2）是新近分离鉴定的第7种可以感染人类的冠状病毒,已确认为目前正在暴发流行的COVID-19的病原体。SARS-CoV-2可在COVID-19患者的支气管肺泡灌洗液、鼻咽拭子、血液等样本中检出,细胞分离培养相对容易。鉴于病毒培养分离和病原学鉴定对病毒复制增殖、致病免疫、检测诊断和特异防治等都具有重要意义,此文就SARS-CoV-2分离、病原学鉴定以及根据宏基因组测序的反向病原学研究现状与进展做一综述。     

中药抗呼吸道合胞病毒实验研究进展

中药具有高效低毒的特点,分别从抗呼吸道合胞病毒(RSV)复方和单味中药提取物2个方面,总结中药对RSV的实验抑菌作用及其作用机制,期待为临床治疗提供理论依据,并为进一步挖掘和深入研究中药抗病毒成分提供新的思路。同时指出了单味中药提取物虽然可以较为清晰地说明治疗机制和作用靶点,但目前多数尚停留在物质分析、鉴定和少数动物细胞实验阶段。