Stem cell factor enhances the survival but not the self-renewal of murine hematopoietic long-term repopulating cells

The effects of stem cell factor (SCF) have been tested on a murine bone marrow subpopulation (RH123lo, Lin-, Ly6A/E+) that is highly enriched for long-term hematopoietic repopulating cells. SCF maintained cells from this population with long-term repopulating ability for up to 10 days in vitro. However, compared with freshly isolated cells, the level of engraftment in vivo by the cultured cells declined during the in vitro culture period, suggesting that SCF alone was unable to stimulate the self-renewal of long-term repopulating cells. By direct visualization of cultures, only small numbers of cells survived and rarely underwent cell division. However, SCF did directly stimulate proliferation of a population (Rh123med/hi,Lin-,Ly6A/E+) enriched for short-term repopulating cells. These data suggest that stem cell differentiation is associated with the development of mitogenic activity by SCF at least in some progenitor cell populations.     

IgMs produced by two acquired immune deficiency syndrome lymphoma cell lines: Ig binding specificity and VH-gene putative somatic mutation analysis [published erratum appears in Blood 1994 Aug 1;84(3):995]

Two B-cell lines, 2F7 and 10C9, were established by single cell cloning from biopsies obtained from two acquired immune deficiency syndrome patients with Burkitt's lymphoma. Representation of the original tumors was verified by demonstration of (1) identical biallelic rearrangement of Ig genes for 2F7 and (2) shared idiotype for 10C9. Both cell lines displayed cell-surface Ig and secreted Ig (IgM lambda for 2F7, IgM kappa for 10C9). IgMs from both cell lines immunoprecipitated actin; in addition, 2F7 IgM lambda immunoprecipitated recombinant human immunodeficiency virus type 1 (HIV-1) gp 160. 2F7 IgM lambda did not react with other autoantigens (double-stranded and single-stranded DNA, actin, bovine serum albumin, IgG), whereas 10C9 IgM kappa reacted with human IgG. The 2F7 IgM heavy-chain variable region (VH) showed a 95% nucleotide homology with a previously sequenced VHIII germline gene, hv3019b9, whereas the 10C9 IgM VH showed a 95% homology with a previously sequenced VHIV germline gene, VH4.21. Use of minimally modified VH genes and demonstration of reactivity with chronically present antigens (ie, actin, HIV-1 gp 160, or human IgG) suggests that B cells in HIV-1-infected individuals proliferating in response to chronic antigenic stimulation may be at increased risk for lymphomagenesis.     

Incidence, clinical significance and prognosis of ventricular fibrillation in the early phase of myocardial infarction

Of 1265 patients admitted to the CCU with the diagnosis of acuteMI, 96 (7.6%) developed ventricular fibrillation within 72 hoursfollowing admission. Of these 96, 35 (36.5%) had secondary VFassociated with left ventricular failure; they had a high in-hospitalmortality of 57.1%. The remaining 61 (63.5%) had primary VF,i.e. VF occurring in the absence of significant LV failure.Fourteen of these (23%) died in hospital: 9 due to PVF (3 duringthe first episode, 6 during a recurrence). This mortality figurewas significantly higher (P<0.001) than the mortality of10% seen among patients who did not experience VF. Primary VFshowed a recurrence rate of 20%. Compared with the 1061 patientswho left the hospital without primary VF, the 61 subjects withthis rhythm disorder were older, had larger infarcts and morefrequent complications, such as pericarditis, conduction abnormalities,frequent ventricular premature contractions and signs of rightventricular failure. These findings, in contrast with a widelyheld view, suggest that primary VFmay carry a guarded prognosis.     

The First Case Report of Schnitzler Syndrome Presenting with Eye Pain

ABSTRACT

Schnitzler syndrome is a rare, auto inflammatory condition known to manifest with bone pain, urticarial rash, fevers, relapsing arthralgia, and fatigue. In this case report, we describe a patient who was diagnosed with Schnitzler Syndrome that had initially presented with a unilateral pressure-type headache with a sensation of a ‘dagger’ stabbing into the back of the eye. He also had an associated ipsilateral redness of the conjunctiva, eyelid swelling, subtle optic disc elevations bilaterally and facial flushing - but with no visual acuity, pupillary, or lacrimatory changes. Anterior segment, fundoscopy, intraocular pressures and extraocular muscle movements were otherwise normal.     

Unique changes in interstitial extracellular matrix composition are associated with rejection and cyclosporine toxicity in human renal allograft biopsies

Renal allograft loss from chronic rejection or cyclosporine toxicity (CsAT) is characterized by progressive interstitial fibrosis, yet the protein composition of these lesions is unknown. The normal tubular basement membrane (TBM) contains laminin (LM), collagen IV (containing collagen IV alpha chain 1 [COL4A1] and COL4A2), thrombospondin (TSP), and fibronectin (FN). Only TSP and FN extend beyond the TBM into the interstitial space. Very scanty amounts of interstitial collagens (I and III) are detected in the interstitium. In a pilot study of human renal allograft biopsy specimens, three patterns of extracellular matrix (ECM) composition were identified. Pattern 1 showed no change in ECM composition; pattern 2 showed generalized accumulation of collagens I and III in the interstitium; and pattern 3 showed new expression of COL4A3 and LM-beta2 in the proximal TBM. Criteria were established for the clinicopathological diagnosis of CsAT and rejection. These diagnoses were correlated with the ECM composition in 22 renal allograft biopsy specimens. Control groups were examined in a similar manner and included native kidney biopsy specimens from patients with other allografts (n = 7), renal biopsy specimens from patients with glomerular disease (n = 9), and renal allograft biopsy specimens from patients without clinicopathological evidence of renal disease. These data show that rejection is associated with pattern 3 and CsAT is associated with pattern 2. Thus, detection of ECM composition may be a useful adjunct to standard microscopy in distinguishing rejection from CsAT in renal allograft biopsy specimens. These data suggest that interstitial fibrosis associated with rejection and CsAT result from different pathogenic mechanisms.     

开放性结肠直肠切除术后的腹内游离气体

立位Ｘ线胸片可敏感而特异地显示膈下游离气体 ,对开放性结肠直肠切除术后空腔脏器出现破损是一项有效的检查 ,但由于剖腹术后气腹自然吸收所需要的时间未知 ,其作用尚未被确定。本次试验的目的即在于确定这一时间。　　 3个月内连续 92例接受了连续性结肠直肠切除术的病人 (8例拒绝合作 ,9例采用了腹腔镜技术 )中的 75例参与了这次试验 (平均年龄 6 2 1岁 ,男∶女 =1 3∶1) ,手术指征分别为直肠癌 6例 ,憩室病 2例 ,肠道炎症 2例 ,放疗引起狭窄 3例 ,功能性疾患 (慢性运输性便秘 ,直肠脱垂 ) 2例 ,其它 (家族性腺瘤息肉、乙状结肠扭转、短…     

骨形态发生蛋白2表达异常与脊柱的融合

目的:综述近几年来国内外对骨形态发生蛋白2表达异常及其基因突变的研究,重点分析突变对脊柱融合的影响,为基因重组骨移植提供理论依据。资料来源:应用计算机检索Medline和Science Direct Online数据库1989-01/2007-01期间与骨形态发生蛋白2表达异常及脊柱融合相关的文章,检索词为"BMP2,BMP,gene mutation,mutation,gene expression,abnormal expression,spinal fusion,bony fusion,bone transplantation",限定文章语言种类为English。同时计算机检索中国期刊全文数据库2000-01/2007-01期间与骨形态发生蛋白2表达异常及脊柱融合相关的文章,检索词为"骨形态发生蛋白2,脊柱融合,骨移植,基因突变,表达异常",限定文章语言种类为中文。资料选择:对资料进行初审,选择有关骨形态发生蛋白2生物学活性、信号转导机制、基因突变、与骨诱导的关系、在脊柱融合中的研究进展的文献,共收集到121篇,排除综述类及重复研究。资料提炼:选择其中有代表性的30篇进行综述,涉及到骨形态发生蛋白2的生物学活性、诱导成骨机制、突变的分子学基础、基因突变及影响蛋白表达异常的其他因素。资料综合:骨移植植骨融合的形成是一个多因子、多基因的过程,涉及到骨生成、骨诱导和骨传导3个环节。骨形态发生蛋白2是骨发育和修复的关键调节剂,骨折愈合时尤其需要。国内外学者对于骨形态发生蛋白2基因的自身突变研究取得了很大进展,已检测出不同部位多个位点的突变。基因变异导致所编码氨基酸发生改变,从而引起相应多肽结构发生变异,影响蛋白质的理化性质。无论是体内的骨形态发生蛋白2抑制因子,突变导致的生物活性改变,还是其增龄性效应,最终都将引起局部骨形态发生蛋白2含量下降及生物学活性减退,可能直接导致脊柱融合术后植骨愈合不良或植骨不愈合的发生。结论:对骨形态发生蛋白2表达异常尤其对其基因进行突变分析,寻找影响植骨融合的遗传学因素,具有非常重要的临床意义。