Clinical and experimental vasogenic edema: in vivo sodium MR imaging. Work in progress

To investigate the sodium magnetic resonance (MR) imaging characteristics of acute vasogenic edema, an experimental canine model was developed. Vasogenic edema was produced in the hemisphere of the dogs by the intraarterial infusion of hypertonic mannitol (25%). This solution opens the blood-brain barrier, allowing the influx of water, electrolytes, and proteins into the brain. The main advantage of this model over the established "cold injury" model is the lack of associated brain necrosis. Two patients with chronic vasogenic edema secondary to well-circumscribed meningiomas also underwent MR imaging. The sodium signal was markedly elevated in both clinical and experimental studies of vasogenic edema fluid compared with signal in healthy brain tissue. Extracellular sodium associated with vasogenic edema displayed MR imaging characteristics similar to that of sodium in serum. There was a trend toward a shortened T2 in edema fluid secondary to the presence of serum macromolecules.     

Intra-articular glucocorticoids in early juvenile chronic arthritis

The efficacy of intra-articular glucocorticoid injections in the early phase of knee joint synovitis was studied in 79 children with juvenile chronic arthritis (42 girls and 37 boys). Half of the injections were given within the first six months from the onset of the disease. The probability of a patient staying in remission was much higher in triamcinolone-treated patients than in patients receiving methylprcdni-solone ( p <0.0005, Breslow statistics). Using multivariate analysis there was a significant association between the length of remission and the synovial fluid polymorphonuclcar leucocyte proportion (SF-PMN%. Patients with a high SF-PMN% tended to have shorter remissions than those with a low SF-PMN% (improvement of the fit in stcpwise model: chi-square = 8.81, p <0.005). The difference between triamcinolone and methylprednisolone groups was still clearly evident two years after injection.     

Anterior cruciate ligament tears: MR imaging compared with arthroscopy and clinical tests

Seventy-nine magnetic resonance (MR) studies of the knee were reviewed in an evaluation of the ability of MR imaging to demonstrate arthroscopically proved anterior cruciate ligament (ACL) tears. MR findings were also compared with the findings of two commonly applied clinical tests of ACL instability: the Lachman test and the anterior drawer test. The sensitivity of MR imaging was 94% (17 of 18), compared with 78% (14 of 18) for the anterior drawer test and 89% (16 of 18) for the Lachman test. The specificity was 100% for all three. Three MR criteria were applied: irregularity or a wavy contour of the anterior margin of the ligament, high-signal-intensity change within the substance of the ligament on T2-weighted images, and discontinuity of that substance. The sagittal T2-weighted image was especially helpful, producing an "arthrographic" effect, in which the anterior margin of the ACL is outlined by high-signal-intensity joint fluid. By demonstrating ACL and other extrameniscal lesions, MR imaging may help clarify the mechanisms of knee injury.     

Familial cerebral cavernous haemangioma diagnosed in an infant with a rapidly growing cerebral lesion

Cavernous haemangiomas of the central nervous system are vascular malformations best imaged by MRI. They may present at any age, but to our knowledge only 39 cases in the first year of life have previously been reported. A familial form has been described and some of the underlying genetic mutations have recently been discovered. We present the clinical features and serial MRI findings of an 8‐week‐old boy who presented with subacute intracranial haemorrhage followed by rapid growth of a surgically proven cavernous haemangioma, mimicking a tumour. He also developed new lesions. A strong family history of neurological disease was elucidated. A familial form of cavernous haemangioma was confirmed by identification of a KRIT 1 gene mutation and cavernous haemangiomas in the patient and other family members. We stress the importance of considering cavernous haemangiomas in the context of intracerebral haemorrhage and in the differential diagnosis of rapidly growing lesions in this age group. The family history is also important in screening for familial disease.     

大鼠、兔和人关节软骨组织形态学的比较

目的:观察比较大鼠、兔和人正常关节软骨组织学结构和关节炎软骨病理变化的差异。方法:实验于2006-08/2007-04在北京大学运动医学研究所完成。取大鼠、兔和人正常的关节滑车软骨和关节炎的滑车软骨,人关节软骨来源告知患者并征得同意,进行苏木精-伊红和甲苯胺蓝组织学染色,观察正常关节软骨的形态结构及关节炎软骨的病理变化。结果:关节软骨具有明显的分层,3者的主要区别在于软骨的第三层和潮线。大鼠软骨的第三层是典型的肥大细胞,无潮线;兔软骨的第三层是典型的柱状细胞层,潮线明显;人的软骨第三层为深层带,细胞较大,形态不规则,有多核细胞存在,有明显的潮线。正常软骨甲苯胺蓝染色均匀。关节炎软骨变化从表面开始,大鼠表现为表层软骨纤维样变,肥大细胞消失;兔和人表现为表层软骨细胞坏死,深层细胞排列紊乱。甲苯胺蓝染色失染或染色不均。结论:大鼠、兔和人的关节软骨结构不尽相同,主要差别在第三层和潮线的有无。关节炎软骨的变化也各有异同,但兔的软骨变化更接近于人。     

Activation of the contact system in insect-sting anaphylaxis: association with the development of angioedema and shock

A postulated role of the contact system in anaphylactic reactions to insect stings was investigated. During prospective, in-hospital sting challenge, we collected serial blood samples from five normal volunteers and 16 patients with a history of insect-sting anaphylaxis. Activation of the contact system was assessed by measuring plasma levels of factor XIIa-C1-inhibitor and kallikrein-C1-inhibitor complexes as well as those of cleaved high molecular weight kininogen (HK). In addition, antigenic levels of (pre)kallikrein, factor XII, and HK were measured. No significant changes in contact system parameters were observed in any of the five volunteers or the four patients who did not develop an anaphylactic reaction after sting challenge. In contrast, significant changes in contact system parameters occurred in 7 of the 12 patients with anaphylactic symptoms after challenge. Peak levels of either C1-inhibitor complex were found 5 minutes after the onset of anaphylactic symptoms. The increase in C1-inhibitor was most pronounced in the 4 patients with angioedema, 2 of which also developed shock. However, activation of HK was observed in all four patients with angioedema, the two patients with shock but no angioedema, as well as in 1 of the remaining 6 patients with anaphylactic symptoms other than angioedema or shock. Thus, activation products of the contact system may be involved in the pathogenesis of angioedema and shock in insect- sting anaphylaxis.     

The putative factor IX gene promoter in hemophilia B Leyden

Hemophilia B Leyden is characterized by low levels of factor IX antigen and activity before the age of 15, whereas after puberty factor IX levels rise at a rate of about 5% per year. A single base substitution (-A----T) at position -20 was identified in the putative promoter of the gene cloned from a patient with hemophilia B Leyden. This nucleotide change was confirmed in a second patient from the same pedigree and was also found in a patient from a second Dutch pedigree with the same hemophilic phenotype. The results indicate that the two Dutch kindreds are related and point to the functional significance of the -20 position for the expression of the human factor IX gene.     

Modulation of neutrophil oxidative responses to soluble stimuli by platelet-activating factor

The role of platelet activating factor (PAF) as a regulator of human neutrophil superoxide (O2-) generation in response to soluble and particulate stimuli was examined. At concentrations greater than 10(-7) mol/L, PAF alone induced a brief burst of O2- production. When cells were exposed to PAF and either the chemotactic peptide n-formyl- methionyl-leucyl-phenylalanine (FMLP 10(-7) mol/L) or the tumor promoter phorbol myristate acetate (PMA 10 ng/mL), a marked synergistic augmentation of O2- release was noted when compared to control cells stimulated with FMLP or PMA alone. Mean percentage of enhancement by 10(-5) mol/L of PAF was 297% +/- 35% (n = 9) of control responses to FMLP and 185% +/- 16% (n = 3) of control responses to PMA. Consistent enhancement occurred with PAF concentrations of as low as 10(-9) mol/L. Enhancement could be demonstrated when neutrophils were exposed to PAF either at the same time as, or up to 60 minutes prior to, the second stimulus, and was neither reversed by removal of PAF from the medium prior to addition of FMLP or PMA nor dependent on the presence of extracellular divalent cations. Continuous recordings revealed that the enhancement was due to an increased maximal rate of O2- production. In contrast, PAF concentrations up to 10(-5) mol/L had only a minimal effect on the response to neutrophils to opsonized zymosan. Analysis of the enhancing properties of lipids structurally related to PAF revealed that the critical moiety was the saturated fatty acid at position 1. These results indicate the presence of a PAF-mediated positive feedback loop whereby the oxidative burst induced by some soluble stimuli is augmented. Modulation of neutrophil O2- production by PAF may serve to amplify neutrophil oxidative responses at sites of inflammation.     

Lysis of human fibroblast colony-forming cells and endothelial cells by monoclonal antibody (6-19) and complement

The murine IgG2a monoclonal antibody 6-19 binds to a wide variety of nonhematopoietic cells including human marrow-derived stromal cells but does not bind to marrow or peripheral blood cells. We studied the effects of this antibody and rabbit complement on marrow cells. Fibroblast colonies were eliminated from light density marrow cells by a single incubation with monoclonal antibody 6-19 and complement. The growth and composition of granulocytic and erythroid colonies were unaffected. Specific complement mediated cytotoxicity of the antibody was confirmed on passaged human fibroblasts derived from marrow (more than 99.6% of fibroblasts are killed by a single treatment). Similar results were obtained with human umbilical cord endothelial cells. In addition, such treatment abolished the initiation of Dexter culture stroma. Incubation of bone marrow cell suspensions with this antibody and complement will allow the study of stroma-free marrow cells in long- term liquid cultures.     

Rates of sustained virological response 12 weeks after the scheduled end of direct‐acting antiviral (DAA)‐based hepatitis C virus (HCV) therapy from the National German HCV registry: does HIV coinfection impair the response to DAA combination therapy?

Objectives

The European Association for the Study of the Liver (EASL) treatment recommendations for hepatitis C no longer discriminate between HIV/hepatitis C virus (HCV)‐coinfected and HCV‐monoinfected patients. However, recent data from Spain are questioning these recommendations on the basis of the findings of higher relapse rates and lower cure rates in HIV/HCV‐infected subjects. The aim of our study was to compare HCV cure rates in monoinfected and coinfected patients from Germany.

Methods

Data acquired from the Deutsches Hepatitis C‐Registry were analysed. A total of 5657 HCV‐monoinfected subjects and 488 HIV/HCV‐coinfected patients were included in the study. Rates of sustained virological response 12 weeks after the scheduled end of therapy (SVR12) were collected in both subgroups and in cirrhotic and noncirrhotic patients.

Results

HIV/HCV‐coinfected patients were more frequently male (84.6% vs. 56.4%, respectively; P < 0.001) and younger than HCV‐monoinfected subjects (46.5 ± 9 vs. 53.8 ± 12.5 years, respectively; P < 0.001). The CD4 blood cell count was > 350 cells/μL in 63.1% of HIV‐positive subjects and 88.7% were on antiretroviral therapy. SVR12 rates were 90.3% (5111 of 5657) in our HCV‐monoinfected cohort and 91.2% (445 of 488) in our coinfected patients. Liver cirrhosis was confirmed in 1667 of 5657 (29.5%) monoinfected patients and 84 of 488 (17.2%; P < 0.001) coinfected patients. SVR12 rates did not differ between HCV‐monoinfected and HIV/HCV‐coinfected patients with liver cirrhosis (87.8% vs. 89.3%, respectively; P = 0.864). A treatment duration of 8 weeks did not reduce the percentage of patients with SVR12 in either subgroup (93.7% in both groups).

Conclusions

We found high SVR12 rates in monoinfected as well as coinfected individuals. No differences were detected between the two subgroups regardless of whether there was accompanying liver cirrhosis or a shortened treatment duration.