炎症性肠病及其干细胞移植再生修复

炎症性肠病(IBD)在我国发病率逐步升高,其相关病理学研究和再生修复成为研究的热点.炎症性肠病存在易感基因NOD2,发病与感染、饮食、药物、肠道菌群变化及免疫因素有关.肠道干细胞,具有自我更新与增殖能力.肠黏膜被破坏时,陷窝残存的干细胞向外生长并移行,重建绒毛直至肠黏膜恢复正常.肠道干细胞的增殖和分化与多种细胞因子作用有关.造血干细胞移植治疗IBD是最近出现的一种新型治疗方法,自体与异体移植均有较好临床疗效,基础研究已经证实移植的造血干细胞可以定居于肠道上皮,但移植修复损伤肠道黏膜的详细机制则有待于深入研究.     

Neural respiratory drive in healthy subjects and in COPD

The aim of the present study was to use the diaphragm electromyogram (EMG(di)) to compare levels of neural respiratory drive (NRD) in a cohort of healthy subjects and chronic obstructive pulmonary disease (COPD) patients, and to investigate the relationship between NRD and pulmonary function in COPD. EMG(di) was recorded at rest and normalised to peak EMG(di) recorded during maximum inspiratory manoeuvres (EMG(di) % max) in 100 healthy subjects and 30 patients with COPD, using a multipair oesophageal electrode. EMG(di) was normalised to the amplitude of the diaphragm compound muscle action potential (CMAP(di,MS)) in 64 healthy subjects. The mean+/-sd EMG(di) % max was 9.0+/-3.4% in healthy subjects and 27.9+/-9.9% in COPD patients, and correlated with percentage predicted forced expiratory volume in one second, vital capacity and inspiratory capacity in patients. EMG(di) % max was higher in healthy subjects aged 51-80 yrs than in those aged 18-50 yrs (11.4+/-3.4 versus 8.2+/-2.9%, respectively). Observations in the healthy group were similar when peak EMG(di) or CMAP(di,MS) were used to normalise EMG(di). Levels of neural respiratory drive were higher in chronic obstructive pulmonary disease patients than healthy subjects, and related to disease severity. Diaphragm compound muscle action potential could be used to normalise diaphragm electromyogram if volitional inspiratory manoeuvres could not be performed, allowing translation of the technique to critically ill and ventilated patients.     

A prospective multicenter evaluation of a new side‐port endoscopic ultrasound‐fine‐needle aspiration in solid upper gastrointestinal lesions

Background and Study Aims: Diagnostic yield of endoscopic ultrasound (EUS)‐fine‐needle aspiration (FNA) varies depending on the equipment used and the site targeted. Multiple needle passes are usually required to obtain a diagnosis. A new needle incorporating a side‐port carries a theoretical advantage regarding acquisition of cytological material. The aim of the study was to demonstrate the safety and efficacy of the Olympus side‐port needle in solid upper gastrointestinal indications. Patients and Methods: A prospective multicenter evaluation of patients referred for EUS‐FNA for solid lesions was performed across six tertiary gastroenterology referral centers in four capital cities in Australia. The main outcome measures include cytological diagnosis, number of needle passes required for diagnosis and complication rates. Results: Thirty patients (17 men; 13 women) with a mean age of 67.5 years were studied. Indications included pancreatic or biliary mass in 24 patients, retroperitoneal or periduodenal mass in 2, enlarged lymph node in 2, a gastric submucosal tumor in 1 and a subcarinal mass in 1. The mean size of the lesions was 3.47 cm (range, 0.5–8 cm). All but one case had a diagnosis made (96.7%). The mean number of passes required to reach a diagnosis was 1.7. In neoplastic lesions the diagnosis was made with a mean of 1.6 passes. No complications were encountered. Conclusions: The new EUS‐FNA needle with side port appears effective and safe in solid upper gastrointestinal EUS‐FNA indications.     

Photochemical inactivation of viruses and bacteria in platelet concentrates by use of a novel psoralen and long-wavelength ultraviolet light

BACKGROUND: A photochemical treatment process has been developed for the inactivation of viruses and bacteria in platelet concentrates. This process is based on the photochemical reaction of a novel psoralen, S- 59, with nucleic acids upon illumination with long-wavelength ultraviolet light (UVA, 320–400 nm). STUDY DESIGN AND METHODS: High levels of pathogens were added to single-donor platelet concentrates containing 3 to 5 × 10(11) platelets in 300 mL of 35-percent autologous plasma and 65-percent platelet additive solution. After treatment with S-59 (150 microM) and UVA (0-3 J/cm2), the infectivity of each pathogen was measured with established biologic assays. In vitro platelet function after photochemical treatment was evaluated during 7 days of storage by using a panel of 14 assays. The in vivo recovery and life span of photochemically treated platelets were evaluated after 24 hours of storage in a primate transfusion model. RESULTS: The following levels of pathogen inactivation were achieved:>10(6.7) plaque-forming units (PFU) per mL of cell-free human immunodeficiency virus (HIV),>10(6.6) PFU per mL of cell-associated HIV,>10(6.8) infectious dose (ID50) per mL of duck hepatitis B virus (a model for hepatitis B virus),>10(6.5) PFU per mL of bovine viral diarrhea virus (a model for hepatitis C virus),>10(6.6) colony-forming units of Staphylococcus epidermidis, and>10(5.6) colony-forming units of Klebsiella pneumoniae. Expression of integrated HIV was inhibited by 0.1 microM S- 59 and 1 J per cm2 of UVA. In vitro and in vivo platelet function were adequately maintained after antiviral and antibacterial treatment. CONCLUSION: Photochemical treatment of platelet concentrates offers the potential for reducing transfusion-related viral and bacterial diseases.     

Intracellular calcium dependence of gene expression in single T lymphocytes.

In T lymphocytes, intracellular Ca2+ concentration ([Ca2+]i) rises within seconds of T-cell antigen-receptor stimulation and initiates the synthesis and secretion of interleukin 2, a cytokine essential for T-cell proliferation and the immune response. Using video-imaging techniques, we tracked [Ca2+]i signals in individual T cells and measured subsequent expression of a beta-galactosidase reporter gene (lacZ) controlled by the NF-AT element of the interleukin 2 enhancer. [Ca2+]i spikes elicited by monoclonal antibody binding to the CD3 epsilon subunit of the T-cell receptor were positively correlated with gene expression, but varied widely between individual cells and were therefore difficult to relate quantitatively to lacZ expression. The [Ca2+]i dependence of NF-AT-regulated gene expression was determined by elevating [Ca2+]i with either thapsigargin or ionomycin and then "clamping" [Ca2+]i to various, stable levels by altering either extracellular [Ca2+] or extracellular [K+]. Raising [Ca2+]i from resting levels of 70 nM to between 200 nM and 1.6 microM increased the fraction of cells expressing lacZ, with Kd approximately 1 microM. Activation of protein kinase C enhanced the [Ca2+]i sensitivity of gene expression (Kd = 210 nM), whereas stimulation of protein kinase A inhibited [Ca2+]i-dependent gene expression. The experiments described here provide single-cell measurements linking a second messenger to gene expression in individual cells.     

Synergistic effect of granulocyte-macrophage colony-stimulating factor and 1,25-dihydroxyvitamin D3 on the differentiation of the human monocytic cell line U937

The human monoblastlike cell line U937 can be induced to differentiate by a variety of agents including gamma-interferon, phorbol esters, retinoic acid, and 1,25-dihydroxyvitamin D3 (VD3). Incubation of U937 with 1 to 1,000 units of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) did not induce macrophage differentiation. A synergistic effect on macrophage differentiation was observed, however, when U937 was cocultured with 10(-8) mol/L VD3 plus 50 U/mL GM-CSF. GM-CSF-plus VD3-treated cells demonstrated significant increases in OKM1 antigen expression, increased chemokinesis and chemotaxis, and increased Fc receptor-mediated erythrophagocytosis. Human peripheral blood monocyte cultures also demonstrated increased OKM1 antigen expression and chemotaxis when incubated with 50 to 500 U/mL of GM-CSF for 48 to 72 hours. VD3, however, was not necessary for the increases in effector function observed for GM-CSF-stimulated monocyte cultures. In distinction to the synergistic effect of GM-CSF on VD3-induced differentiation of U937, recombinant human granulocyte colony-stimulating factor (G-CSF) at comparable concentrations had no augmenting effect over that observed for VD3 alone. These results suggest that GM-CSF, in the presence of other physiological stimuli, can induce significant phenotypic changes in GM-CSF-nonresponsive cells of the monocytic lineage and can increase the effector functions of GM- CSF-responsive peripheral blood monocyte cultures.