A Weaning Reaction to Microbiota Is Required for Resistance to Immunopathologies in the Adult

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Increased cyclosporine sensitivity of T cells from cord blood compared with those from the adult.

Despite the increasing numbers of paediatric transplants performed, little is known about the immune responses of T lymphocytes in human neonates. Here we have compared the effects of cyclosporine on the phytohaemagglutinin (PHA) response of immature (cord) and mature (adult) lymphocytes using the following parameters of activation: (i) proliferation, measured by 3H-thymidine uptake; (ii) expression of cell surface IL-2 receptor; (iii) release of IL-2 into the supernatant. Cyclosporine was added to cultures of PHA-stimulated lymphocytes at doses ranging from 5 to 5000 ng/ml. The proliferative response of cord lymphocytes was considerably more sensitive to cyclosporine at each dose, so that 50% inhibition was achieved by 6 ng/ml and 21.5 ng/ml doses of cyclosporine on cord and adult lymphocytes, respectively. Expression of the IL-2 receptor by PHA-activated T cells and their subsets was assessed by flow cytometry. Cyclosporine inhibited IL-2 receptor expression to a significantly greater degree in cord CD4 and CD8 cells (49.7% and 70.1%) than in adults (17.9% and 30.0%). Biologically active IL-2 release was measured using the IL-2-dependent cell line CTLL-2. Cyclosporine at doses 50-5000 ng/ml produced 80-99% inhibition of both cord and adult responses. However, at very low doses (5 ng/ml) cyclosporine produced 69.3% inhibition of cord lymphocytes, compared with 42.0% of adult lymphocytes. These results suggest that the T cells of neonates are considerably more sensitive to cyclosporine than are adult T cells.     

Identification of the membrane protein of porcine epidemic diarrhea virus

Sequence information on the genome of porcine epidemic diarrhea virus (PEDV) has only recently been determined. In contrast, very little is known about the viral proteins. In the present report we have identified the membrane glycoprotein (M) of PEDV by use of rabbit anti-peptide sera and transient expression of the cloned M gene in Vero cells and by expression in the baculovirus system. The native M protein of PEDV is incorporated into virions, is N-glycosylated, and migrates with a relative mobility (Mr) of 27 k in polyacrylamide gels. In contrast, the M protein synthesized by recombinant baculoviruses migrates with a Mr of 23 k, that is, with identical mobility as the deglycosylated product of PEDV. Thus, it appears that M protein specified by the recombinant baculovirus is poorly, if at all, glycosylated. Using monoclonal antibodies and rabbit antipeptide sera specific for the N and C termini of the M protein, we were able to show that a 19 k band detected in PEDV-infected cells but not in virions represented a fragment of M from which the C terminus had been cleaved off. Finally, by electron microscopy and immunogold labelling, the relative orientation of M within the virion envelope was determined as NexoCcyt. In conclusion, all of these data strongly support the hypothesis that PEDV should be classified with the group I coronaviruses.     

Secretin dissipates red aridine orange fluoescence from pancreatic duct epithelium

This study was undertaken to elucidate whether duct cells in the pancreas contain acidic cytoplasmic compartments regulated by secretion. Microdissected pancreatic ducts from pigs were examined by acridibe orange (AO) and 2′, 7′-biscarboxyethyl-5(6)-carboxyfluorescein/tetraacetioxymethyl ester (BCECF/AM) epifluorescence microscopy. Estimated cytoplasmic pH using BCECF fluorescence was 7.43pL0.04 and was not changed by altering CO₂ tension in the incubation mdium. The epithelium of acridine orange incbated peripheral interlobular pancreatic ducts exhibited green and fluorescence was sen in resting pancreatic ducts and was greatly accentuated by raising CO₂ in the incubation medium with chloroqyuine or NH₄Cl or the protonophores carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) or carbonyl cyanide M-chlorophenylhydrazone (CCCP), leaving uniform gren fluoresence. These findings suggest that pancreatic duct cells contain CO₂-dependent acidic compartments which vanishduring seceatin stimulation and which may be cytoplasmic tubulovesicles.     

早期新生儿死亡病因学研究进展

早期新生儿死亡属于围产儿死亡的一部分,其定义为新生儿出生后0~6天死亡。通常认为男性新生儿、先天异常、早产、低出生体重和5分钟Apgar评分低于7分等是早期新生儿死亡最常见的相关因素。但是仍有相当多的早期新生儿死亡病因不明,其为产科及儿科医务人员比较棘手的问题,也容易引发医患矛盾。近年来发现,除上述常见的病因外,基因缺陷和代谢性疾病在早期新生儿死亡中亦占有相当的比例,而通过全基因测序和串联质谱检测技术,可能对寻找部分既往被归于不明原因早期新生儿死亡病例的病因有一定的帮助。该文就早期新生儿死亡病因及可能机制、病因评估方法等进行综述。     

胰腺电子计算机体层扫描增强扫描参数研究

目的 :研究不同扫描参数对胰腺电子计算机体层扫描 (CT)增强的影响 ,以得出合适的扫描方案。方法 :1预试验 10例 ,按 1.5 ml/ kg、3ml/ s注射造影剂 (Omnipaque 30 0 mg I/ m l)行胰腺薄层三期扫描 ,动脉期、胰腺期及门脉期的延迟时间各为 18s、40 s、70 s,分别测量平均胰腺 CT增强值并作比较。2将 40例患者按不同剂量和注射速度随机分成 4组 , 组 (1.5 ml/ kg、3.0ml/ s) , 组 (1.5 ml/ kg、2 .5 m l/ s) , 组 (1.0 ml/ kg、3.0 m l/ s) , 组 (1.0 ml/ kg、2 .5 ml/ s)每组各 10例 ,分别行胰腺期、门脉期扫描 ,分别测量平均胰腺 CT增强值并作比较。结果 :预试验中发现平均胰腺 CT增强值 ,胰腺期 [(6 9.5 6± 10 .6 ) Hu]比动脉期[(2 4.81± 14.98) Hu]高 (P<0 .0 5 ) ,胰腺期 [(6 9.5 6± 10 .6 ) Hu]比门脉期 [(5 4.38± 10 .34 ) Hu]高 (P<0 .0 5 )。40例对照研究中 ,胰腺期平均胰腺 CT增强值 : 组为 (71.0 5± 9.6 4) Hu, 组为 (6 2 .2 7± 12 .2 9) Hu, 组为 (42 .3± 11.75 ) Hu, 组为(44 .16± 11.2 7) Hu、 组与 组相比 (P<0 .0 5 )、 组与 组相比 (P<0 .0 5 )。 组与 组、 组与 组相比无明显差异。结论 :平均胰腺实质增强胰腺期比动脉期、门脉期好 ,以 1.5 ml/ kg剂量 ,2 .5～ 3.0 m l/ s     

大鼠全胰十二指肠移植术并发症的分析及预防

目的 :探讨建立稳定的大鼠全胰十二指肠移植模型。方法 :采用大鼠全胰十二指肠移植肠道引流术式进行移植手术 50例 ,对术中及术后发生并发症及死亡的 12只大鼠进行解剖 ,分析其死亡原因。结果 :在前 2 5例中 ,由于并发症在 1周内死亡的大鼠 10只 ,存活率为 60 % ;在后 2 5例中 ,对手术操作加以改进 ,有效地防止了并发症的发生 ,1周内死亡 2只 ,存活率达 92 %。结论 :术中及术后发生的并发症多与手术操作有关     

A novel approach to delivery of extracorporeal support using a modified continuous flow ventricular assist device in a mid‐volume congenital heart program

Extracorporeal life support (ECLS) is an essential component of a modern congenital cardiac surgery program. The circuit components and bedside management team may, however, vary among institutions. Here, we evaluate our initial experience with a modified ventricular assist device—based ECLS circuit primarily managed by the bedside nurse. We hypothesize that our outcomes are comparable to Extracorporeal Life Support Organization (ELSO) registry data. All patients who received ECLS from January 1, 2016 to December 31, 2019 at a single institution were included. Primary outcomes were survival to ECLS decannulation and discharge or transfer. Secondary outcomes included complications from ECLS. Data were compared to available ELSO registry data. Thirty‐seven patients underwent 44 ECLS runs during the study period. Forty percent of patients had single ventricle physiology. Nearly 46% of patients received ECLS as part of extracorporeal cardiopulmonary resuscitation (eCPR). Survival to ECLS decannulation (68.2%) and survival to discharge or transfer (61.4%) did not differ from overall ELSO outcomes (69.7%, P = .870 and 50.7%, P = .136), as well as survival to discharge or transfer in a comparable cohort of ELSO centers (53.1%, P = .081). Patients with complications had a lower rate of survival to discharge or transfer but this did not reach statistical significance (47.7% vs. 75.0%, P = .455). Neurologic (50.0%), hemorrhagic (45.5%), and renal complications (31.8%) were most common in this cohort. A modified ventricular assist device‐based ECLS circuit with primary management by the bedside nurse can provide comparable support in a neonatal and pediatric cardiac surgery population. Cost analyses and further delineation of the complication profile are necessary for a complete characterization of this system.