Interleukin-3 and interleukin-7 are alternative growth factors for the same B-cell precursors in the mouse

Clones and lines of precursor (pre) B cells can be established by limiting dilutions of unseparated cell suspensions of fetal liver or bone marrow on stromal cells in the presence of interleukin (IL)-7. When IL-3 is used instead of IL-7, cultures are regularly overgrown by different precursor cells of the myeloid lineage, as well as by adherent cells that inhibit pre-B-cell expansion. However, in the presence of either IL-7 or IL-3, clones of pre-B cells can be established on stroma cells at frequencies near one in one when the cultures are initiated with cell sorter purified CD45RO (B220)+/c-kit+ fetal liver or bone marrow derived pre-B cells. Clones grown on stromal cells in the presence of IL-7 can be regrown in IL-3, and vice versa. Pre-B cells that proliferate on stromal cells in the presence of IL-7 or IL-3 have the same phenotype, ie, are B220+ c-kit+, CD43+, and surrogate light chain+. Removal of the growth factors (IL-7, respectively IL-3) from the cultures results in differentiation to surface immunoglobulin (slg) positive, c-kit-, CD43-, surrogate light chain- B cells, a fraction of which is lipopolysaccharide (LPS) responsive as shown by IgM secretion. These results show that IL-7 and IL-3 stimulate largely overlapping populations of precursor B cells from bone marrow to proliferate for long periods of time in the presence of stromal cells. Thus, IL-7 and IL-3 are alternative growth factors for the same pre-BI cell.     

5-hydroxytryptamine 1A receptor activation protects against N-methyl-D-aspartate-induced apoptotic cell death in striatal and mesencephalic cultures

Apoptosis and glutamate-mediated excitotoxicity may play a role in the pathogenesis of many neurodegenerative disorders, including Parkinson's disease (PD). In the present study, we investigated whether stimulation of the 5-hydroxytryptamine 1A (5-HT1A) receptor attenuates N-methyl-D-aspartate- (NMDA) and 1-methyl-4-phenylpyridinium (MPP(+))-induced apoptotic cell death in cell culture models. A brief exposure (20 min) of M213-2O striatal cells to NMDA and glutamate produced a delayed increase in caspase-3 activity and DNA fragmentation in a dose- and time-dependent manner. NMDA-induced caspase-3 activity and DNA fragmentation were almost completely blocked by the 5-HT1A agonists 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) and (R)-5-fluoro-8 hydroxy-2-(dipropylamino)-tetralin (R-UH-301). Additionally, the protective effects of 8-OH-DPAT and R-UH-301 on NMDA-induced caspase-3 activation and apoptosis were reversed by pretreatment with the 5-HT1A antagonists N-[2-[4-(2-methoxyphenyl)-1-piperazinyl] ethyl]-N-(2-pyridinyl) cyclohexane carboxamide (WAY 100635) and S-UH-301, respectively. Similarly, dose- and time-dependent increases in caspase-3 activity and DNA fragmentation were observed in rat primary mesencephalic neurons after a brief exposure to NMDA and glutamate. Caspase-3 activation and DNA fragmentation in primary mesencephalic neurons were almost completely inhibited by 8-OH-DPAT. This neuroprotective effect of 8-OH-DPAT was reversed by WAY 100635. Additionally, 8-OH-DPAT blocked tyrosine hydroxylase (TH)-positive cell death after NMDA exposure and also almost completely attenuated the NMDA-induced Ca(2+) influx in primary mesencephalic cultures. Furthermore, 8-OH-DPAT and R-UH-301 blocked apoptotic cell death in the primary mesencephalic neurons that were exposed to the Parkinsonian toxin MPP(+). Together, these results suggest that 5-HT1A receptor stimulation may be a promising pharmacological approach in the development of neuroprotective agents for PD.     

Catheter ablation of atrial fibrillation with a multi-electrode radiofrequency balloon; first and early two centre experience in Europe

Introduction

The Heliostar™ ablation system is a novel RF balloon ablation technology with an integrated three-dimensional mapping system. Here, we describe our early experience and procedural outcomes using this technology for atrial fibrillation catheter ablation.

Methods

We sought to comprehensively assess the first 60 consecutive patients undergoing pulmonary vein isolation using the novel HELISOTAR™ RF balloon technology including procedural outcomes. A comparison of the workflow between two different anaesthetic modalities (conscious sedation [CS] vs. general anaesthesia [GA]) was made. Procedural data were collected prospectively from two high-volume centers (Barts Heart Centre, UK and University Hospital of Zurich, Zurich). A standardized approach for catheter ablation was employed.

Results

A total of 35 patients had the procedure under CS and the remaining under GA. Mean procedural and fluoroscopy times were 84 ± 33 min and 1.1 min. The median duration of RF energy application was 7 (5–9.8) mins per patient. All veins were successfully isolated, and the median isolation time was 10 (7–15) seconds. Our cohort's rate of procedural complications was low, with no mortality within 30 days postprocedure.

Conclusion

Our early experience shows that catheter ablation using the Heliostar™ technology can be performed efficiently and safely; however, long-term data is yet to be established. Low fluoroscopy requirements, short learning curves and use of this technology with CS is possible, including the use of an oesophageal temperature probe.     

The impact of late acute rejection after cadaveric kidney transplantation

BACKGROUND: Acute graft rejection (AR) following renal transplantation results in reduced graft survival. However, there is uncertainty regarding the definition, aetiology and long-term graft and patient outcome of AR occurring late in the post-transplant period. AIM: To determine if rejection episodes can be classified by time from transplantation by their impact on graft survival into early acute rejection (EAR) and late acute rejection (LAR). MATERIALS AND METHODS: 687 consecutive adult renal transplant recipients who received their first cadaveric renal transplant at a single centre. All received cyclosporine (CyA)-based immunosuppression, from 1984 to 1996, with a median follow-up of 6.9 yr. Details were abstracted from clinical records, with emphasis on age, sex, co-morbid conditions, HLA matching, rejection episodes, patient and graft survival. ANALYSIS: Patients were classified by the presence and time to AR from the date of transplantation. Using those patients who had no AR (NAR) as a baseline, we determined the relative risk of graft failure by time to rejection. The characteristics of patients who had no rejection, EAR and LAR were compared. RESULTS: Compared with NAR, the risk of graft failure was higher for those patients who suffered a rejection episode. A much higher risk of graft failure was seen when the first rejection episode occurred after 90 d. Thus, a period of 90 d was taken to separate EAR and LAR (relative risk of 3.06 and 5.27 compared with NAR as baseline, p<0.001). Seventy-eight patients (11.4%) had LAR, 271 (39.4%) had EAR and 338 (49.2%) had NAR. The mean age for each of these groups differed (LAR 39.6 yr, EAR 40.8 yr compared with NAR 44 yr, p<0.003). The 5-yr graft survival for those who had LAR was 45% and 10-yr survival was 28%. HLA mismatches were more frequent in those with EAR vs. NAR (zero mismatches in HLA-A: 36 vs. 24%, HLA-B: 35 vs. 23% and HLA-DR: 63 vs. 41%, p<0.003). There was no difference in mismatching frequency between NAR and LAR. CONCLUSIONS: AR had a deleterious impact on graft survival, particularly if occurring after 90 d. AR episodes should therefore be divided into early and late phases. In view of the very poor graft survival associated with LAR, it is important to gain further insight into the main aetiological factors. Those such as suboptimal CyA blood levels and non-compliance with medication should be further investigated with the aim of developing more effective immunosuppressive regimens in order to reduce the incidence of LAR.     

The Effect of Surgical Weight Reduction on Functional Status in Morbidly Obese Patients with Low Back Pain

Background: Although low back (LBP) pain is not a lifethreatening disease, it is a source of significant discomfort and disability and accounts for work absences. It has been shown previously that morbid obesity is associated with increased frequency of LBP and that surgical weight loss improves the symptomatology. However, there are no studies to quantitatively assess the exact degree of functional disability caused by severe obesity and the degree of improvement of LBP that follows weight loss from bariatric surgery. Methods: 29 morbidly obese candidates for bariatric surgery with LBP, weight 132.5±27 (mean±SD) kg and BMI 47.2±8.8 kg/m² were examined for their functional status using psychometric instruments specifically designed to objectively assess the patients' complaints. The preoperative scores were measured by a) visual analogue scales (VAS1, VAS2, VAS3), b) Roland-Morris disability questionnaire, c) Oswestry LBP disability questionnaire, and d) Waddell disability index, and were compared with the scores obtained by the same instruments 2 years after vertical banded gastroplasty. Results: The postoperative weight (92.3±19 kg) and BMI (32.9±6.3 kg/m²) of the 29 patients were significantly reduced (P<0.001). The improved functional disability scores were statistically significant: a) VAS1 1.59±1.86 (mean±SD) vs 0.32±0.64, P<0.001; b) VAS2 5.5±1.97 vs 2.14±1.88, P<0.001; c) VAS3 0.77±1.11 vs 0.09±0.29, P=0.006, d) Roland-Morris 7.89±5.11 vs 1.89±2.13, P<0.001; e) Oswestry 21.22±15.63 vs 5.61±7.51, P<0.001; f) Waddell 2.81±1.37 vs 0.56±0.72, P<0.001. Conclusions: Surgical weight loss significantly improves the degree of functional disability of morbidly obese patients suffering from LBP.     

血管内皮生长因子与基质金属蛋白酶2在血管瘤不同生长过程中的表达特征

目的:观察血管内皮生长因子与基质金属蛋白酶2在血管瘤不同分期中的表达。方法:取自承德医学院附属医院1998-01/2005-12期间血管瘤手术切除的标本共60例及正常带血管皮肤手术切除标本10例,患者家属知情同意。①实验分组:根据Mulliken标准进行病理诊断并分类,所有标本共分4组。增生组22例;退化组20例;退化完成组18例。另取10例正常带血管皮肤组织作为对照组。②采用免疫组织化学S-P法对各组标本的血管内皮生长因子、基质金属蛋白酶2进行染色。③实验评估:以正常血管上皮细胞或肿瘤细胞胞浆出现棕黄色颗粒为阳性,检测各组血管内皮生长因子与基质金属蛋白酶2的表达。结果:①随着血管瘤病理时期的变化,血管内皮生长因子与基质金属蛋白酶2出现明显不同的表达。②增生组血管内皮生长因子与基质金属蛋白酶2的阳性表达率明显高于其他各组,且随着血管瘤的退化,两者的阳性表达率逐渐下降,至退化完成期时与对照组几乎无差别。③血管内皮生长因子与基质金属蛋白酶2的表达呈正相关。结论:血管内皮生长因子与基质金属蛋白酶2在血管瘤的不同分期中起重要作用,其表达水平与血管瘤的病理分期有密切关系。