Prognostic tools for hypertrophic scar formation based on fundamental differences in systemic immunity

Unpredictable hypertrophic scarring (HS) occurs after approximately 35% of all surgical procedures and causes significant physical and psychological complaints. Parallel to the need to understanding the mechanisms underlying HS formation, a prognostic tool is needed. The objective was to determine whether (systemic) immunological differences exist between patients who develop HS and those who develop normotrophic scars (NS) and to assess whether those differences can be used to identify patients prone to developing HS. A prospective cohort study with NS and HS groups in which (a) cytokine release by peripheral blood mononuclear cells (PBMC) and (b) the irritation threshold (IT) after an irritant (sodium lauryl sulphate) patch test was evaluated. Univariate regression analysis of PBMC cytokine secretion showed that low MCP‐1, IL‐8, IL‐18 and IL‐23 levels have a strong correlation with HS (P < .010‐0.004; AUC = 0.790‐0.883). Notably, combinations of two or three cytokines (TNF‐a, MCP‐1 and IL‐23; AUC: 0.942, Nagelkerke R²: 0.727) showed an improved AUC indicating a better correlation with HS than single cytokine analysis. These combination models produce good prognostic results over a broad probability range (sensitivity: 93.8%, specificity 86.7%, accuracy 90,25% between probability 0.3 and 0.7). Furthermore, the HS group had a lower IT than the NS group and an accuracy of 68%. In conclusion, very fundamental immunological differences exist between individuals who develop HS and those who do not, whereas the cytokine assay forms the basis of a predictive prognostic test for HS formation, the less invasive, easily performed irritant skin patch test is more accessible for daily practice.     

An inducible mouse model for microvillus inclusion disease reveals a role for myosin Vb in apical and basolateral trafficking

Microvillus inclusion disease (MVID) is a rare intestinal enteropathy with an onset within a few days to months after birth, resulting in persistent watery diarrhea. Mutations in the myosin Vb gene (MYO5B) have been identified in the majority of MVID patients. However, the exact pathophysiology of MVID still remains unclear. To address the specific role of MYO5B in the intestine, we generated an intestine-specific conditional Myo5b-deficient (Myo5b^fl/fl;Vil-CreERT2) mouse model. We analyzed intestinal tissues and cultured organoids of Myo5b^fl/fl;Vil-CreERT2 mice by electron microscopy, immunofluorescence, and immunohistochemistry. Our data showed that Myo5b^fl/fl;Vil-CreERT2 mice developed severe diarrhea within 4 d after tamoxifen induction. Periodic Acid Schiff and alkaline phosphatase staining revealed subapical accumulation of intracellular vesicles in villus enterocytes. Analysis by electron microscopy confirmed an almost complete absence of apical microvilli, the appearance of microvillus inclusions, and enlarged intercellular spaces in induced Myo5b^fl/fl;Vil-CreERT2 intestines. In addition, we determined that MYO5B is involved not only in apical but also basolateral trafficking of proteins. The analysis of the intestine during the early onset of the disease revealed that subapical accumulation of secretory granules precedes occurrence of microvillus inclusions, indicating involvement of MYO5B in early differentiation of epithelial cells. By comparing our data with a novel MVID patient, we conclude that our mouse model completely recapitulates the intestinal phenotype of human MVID. This includes severe diarrhea, loss of microvilli, occurrence of microvillus inclusions, and subapical secretory granules. Thus, loss of MYO5B disturbs both apical and basolateral trafficking of proteins and causes MVID in mice.Microvillus inclusion disease (MVID) is a rare intestinal enteropathy with autosomal recessive inheritance, which was first described in 1978 (1). MVID patients cannot take up any nutrients and are often completely dependent on parenteral nutrition. The disease is characterized by villus atrophy, (partial) loss of microvilli on the apical plasma membrane of intestinal epithelial cells, and accumulation of intracellular vesicles/vacuoles, containing apical proteins and microvilli (2, 3). In addition, some studies also show mislocalization of apical and basolateral proteins, occasional crypt hyperplasia, and villus fusion (4–6).In the great majority of patients, MVID is caused by mutations in MYO5B, encoding the motorprotein, myosin Vb (5). In two patients, mutations in syntaxin 3 (STX3) caused a variant form of MVID (7). More than 41 unique mutations along the different regions in MYO5B have been identified in MVID patients, including deletions and nonsense, missense, and splice-site mutations (8–10). MYO5B is coding for the actin-based myosin 5b motor protein, which regulates apical membrane trafficking (5, 11). MYO5B functions as a homodimer and has three functional domains: an N-terminal motor domain, a calmodulin-binding domain, and a C-terminal tail, which binds cargo through association with the small GTPases RAB8A and/or RAB11A (12, 13). Altered expression of myosin Vb affects the apical membrane trafficking mechanism in epithelial cells, causing mislocalization of apical brush border proteins, such as villin (vil), CD10, or alkaline phosphatase (ALP) in the cytoplasm of duodenal enterocytes (2, 3, 5), and an increased apical localization of transferrin receptor (5, 14).Although mouse models mimicking certain features of MVID have previously been described, such as Rab8 (15), Cdc42 (16, 17), and Rab11a knockout (KO) mice (18, 19), no mutations in the coding regions of those genes have been reported in human MVID patients. Current in vitro models to study apical trafficking and polarization-associated diseases such as MVID are the parental Caco2 cell line, Caco-BBE, and LS174 W4 cells, in which polarization can be induced in vitro (4, 8, 12, 20). Although valuable knowledge about the function of MYO5B in polarization was gained in these models, the direct relevance of the colon cancer cell lines for the disease is questionable, and diverging results have been obtained with knockdown of MYO5B in the parental Caco2 cells compared with the more polarized Caco-BBE cells (8, 12, 20). As such, we here present an inducible MVID mouse model that recapitulates the genetic defects in man, which allows analysis of the role of MYO5B in a physiological setting and the sequence of events in MVID pathophysiology.     

Racial (vs. self) affirmation as a protective mechanism against the effects of racial exclusion on negative affect and substance use vulnerability among black young adults

Affirming one’s racial identity may help protect against the harmful effects of racial exclusion on substance use cognitions. This study examined whether racial versus self-affirmation (vs. no affirmation) buffers against the effects of racial exclusion on substance use willingness and substance use word associations in Black young adults. It also examined anger as a potential mediator of these effects. After being included, or racially excluded by White peers, participants were assigned to a writing task: self-affirmation, racial-affirmation, or describing their sleep routine (neutral). Racial exclusion predicted greater perceived discrimination and anger. Excluded participants who engaged in racial-affirmation reported reduced perceived discrimination, anger, and fewer substance use cognitions compared to the neutral writing group. This relation between racial-affirmation and lower substance use willingness was mediated by reduced perceived discrimination and anger. Findings suggest racial-affirmation is protective against racial exclusion and, more generally, that ethnic based approaches to minority substance use prevention may have particular potential.     

转化生长因子β1在白细胞介素1β诱导大鼠肾小管上皮细胞转分化及大黄素干预中的作用

目的:大黄素对白细胞介素1β诱导NRK52E细胞转分化有显著抑制作用。实验拟进一步观察转化生长因子β1在白细胞介素1β诱导大鼠肾小管上皮细胞-肌成纤维细胞转分化及大黄素抑制作用中的意义。方法:实验于2006-10/2007-05在泸州医学院附属医院免疫实验室完成。⑴实验材料及分组:以培养的大鼠肾小管上皮细胞株(NRK52E)为观察对象,按如下分组分别添加不同处理因素:①对照组:仅加入体积分数为0.05小牛血清的高糖DMEM培养基。②白细胞介素1β诱导组:加含白细胞介素1β终浓度为10μg/L的高糖DMEM培养基。③SB431542阻断组:加含白细胞介素1β终浓度为10μg/L及SB431542终浓度为10μmol/L的高糖DMEM培养基。④白细胞介素1β 大黄素组:同时加分别含白细胞介素1β终浓度为10μg/L及大黄素终浓度为25mg/L的高糖DMEM培养基。⑵实验评估:培养48h后用倒置相差显微镜观察细胞形态,细胞免疫化学染色法检测肌酸激酶、α-平滑肌肌动蛋白及转化生长因子β1的表达。结果:①白细胞介素1β可诱导部分细胞由卵圆形转变为梭形,且肌酸激酶表达减弱(P<0.01),α-平滑肌肌动蛋白及转化生长因子β1表达显著增强(P<0.01)。②SB431542特异性抑制转化生长因子β1作用后,白细胞介素1β诱导的细胞形态改变受抑,同时肌酸激酶表达增强(P<0.01),α-平滑肌肌动蛋白表达减弱(P<0.01),但转化生长因子β1的表达却无明显变化。③大黄素对白细胞介素1β诱导的细胞形态改变及肌酸激酶、α-平滑肌肌动蛋白的表达有明显抑制作用,其抑制作用与SB431542的作用相比无显著差异;同时,大黄素对白细胞介素1β诱导的转化生长因子β1的表达也有明显抑制作用(P<0.01)。结论:转化生长因子β1可能介导了白细胞介素1β诱导大鼠肾小管上皮细胞-肌成纤维细胞转分化,并参与了大黄素抑制白细胞介素1β诱导大鼠肾小管上皮细胞转分化的作用。     

Demographic characteristics and prevalence of serologic markers among donors who use the confidential unit exclusion process: the Retrovirus Epidemiology Donor Study

BACKGROUND: Most blood centers utilize a confidential unit exclusion (CUE) process, intended to reduce the risk of transfusion-associated infectious diseases by allowing high-risk donors confidentially to exclude their blood from use for transfusion. The effectiveness of this method remains controversial. STUDY DESIGN AND METHODS: Confirmatory or supplemental test results for antibodies to human immunodeficiency virus, human T-lymphotropic virus type I, and hepatitis C virus, as well as hepatitis B surface antigen and syphilis and screening test results for antibodies to hepatitis B core (antigen) and alanine aminotransferase levels were obtained for approximately 1.8 million units donated during 1991 and 1992 at five blood centers within the United States. The prevalences of these infectious disease markers in units that the donors confidentially excluded (CUE+) and units that the donors did not exclude (CUE-) were calculated and examined within demographic subgroups. RESULTS: Units that were CUE+ were 8 to 41 times more likely to be seropositive for antibodies to human immunodeficiency virus and hepatitis C virus, hepatitis B surface antigen, and syphilis and three to four times more likely to react for antibody to hepatitis B core (antigen) or to have elevated alanine aminotransferase levels than units that were CUE- (p < 0.001). The positive predictive value of CUE (the percentage of CUE+ units that were confirmed seropositive for any marker) was 3.5 percent, and the sensitivity of CUE (the percentage of confirmed-seropositive units that were CUE+) was 2.3 percent. CONCLUSION: The current CUE process has low sensitivity and apparently low positive predictive value, and in many cases, it appeared that donors misunderstood it. Yet, CUE was not a “random process,” as CUE+ units were more likely to be seropositive for any infectious disease marker than CUE- units. This suggests that efforts to improve the CUE system may be warranted. As risk factors for transfusion-transmitted infection become more difficult to identify by history-based screening, however, such efforts may have limited effect.     

组织工程细胞支架的免疫原性研究

目的：以组织工程血管脱细胞支架和仿生髓核组织工程细胞支架、周围神经去细胞神经基膜管为例,介绍组织工程脱细胞支架的免疫原性研究情况. 方法：应用计算机检索Medline 1997-01/2007-03关于免疫原性的文章.检索词“Immunotoxicology”并限定文章的语种类为English.同时利用计算机检索中国期刊全文数据库1997-01/2007-03的相关文章,限定文章语言种类为中文,检索词“组织工程,免疫原性”. 结果：主要组织相容性复合体Ⅰ免疫组织化学方法能够检测血管脱细胞支架的免疫原性;组织学观察及反转录-聚合酶链反应检测γ-干扰素、白细胞介素2、白细胞介素4、白细胞介素10 mRNA表达,可以反映仿生髓核组织工程支架的免疫原性;主要组织相容性复合体Ⅱ抗原可以反映出经过化学萃取后的去细胞预变性神经基膜血管结构保留较完整,免疫原性低. 结论：脱细胞可以极大地降低组织工程支架的免疫原性,从而使得组织工程产品有更广阔的使用前景.     

Migraine with aura after intracranial endovascular procedures

OBJECTIVE: To describe three cases of migraine (two with aura) after an intracranial endovascular procedure. Method.-Retrospective. RESULTS: One patient had an attack of migraine with prolonged aura after embolization of a dural arteriovenous fistula. Another patient had an attack of migraine with aura (and hemiparesis) after a diagnostic angiogram. The third patient already suffered from migraine with aura and had a migraine attack after embolization of an occipital arteriovenous malformation. A quadrantanopia persisted in this patient. Outcome of the other two patients was good. CONCLUSION: Intracranial endovascular procedures can induce migraine with aura. We could not identify the underlying pathophysiological mechanism, but mechanical, chemical, immunological, or hemodynamic factors could be involved.     

Electrophysiological safety of sertindole in dogs with normal and remodeled hearts

Inhibition of the potassium current IKr and QT prolongation are associated with drug-induced torsades de pointes arrhythmias (TdP) and sudden cardiac death. We investigated the cardiac electrophysiological effects of sertindole, an antipsychotic drug reported to prolong the QT interval in schizophrenic patients. In cell cultures, sertindole seemed to be a selective blocker of IHERG over other ion currents. For IHERG, the IC50 value was 64 +/- 7 nM, whereas ISCN5A, ICa,L, ICa,T, IKCNQ1/KCNE1, and IKv4.3 were blocked in the micromolar range. In canine ventricular myocytes, the IC50 value for IKr inhibition by sertindole was 107 +/- 21 nM. Action potentials in these cells prolonged in a reverse rate- and concentration-dependent manner at 10 to 300 nM sertindole. In vivo, sertindole was administered to anesthetized dogs at clinically relevant (0.05-0.20 mg/kg) and high doses (1.0-2.0 mg/kg) i.v. At 0.05 to 0.20 mg/kg sertindole (plasma concentrations 30-157 nM), QTc was prolonged by 1 to 5% in normal dogs and by 9 to 20% in dogs with remodeled hearts due to chronic atrioventricular block (CAVB). TdP was not induced at these doses in normal dogs or in CAVB dogs with reproducible induction of TdP by dofetilide in previous experiments. At 1.0 to 2.0 mg/kg sertindole (plasma concentrations 0.5-3.1 microM), QTc prolonged by 6 to 11% in normal dogs and by 22% in dofetilide-sensitive CAVB dogs. TdP occurred in three of five animals in the latter group. Thus, at high i.v. doses sertindole can pose a serious proarrhythmic risk when electrical remodeling of the ventricles is present. At clinically relevant doses, however, sertindole does not cause TdP in anesthetized dogs with normal or remodeled hearts.     

Varenicline increases in vivo striatal dopamine D2/3 receptor binding: an ultra-high-resolution pinhole [123I]IBZM SPECT study in rats

IntroductionEx vivo storage phosphor imaging rat studies reported increased brain dopamine D_2/3 receptor (DRD_2/3) availability following treatment with varenicline, a nicotinergic drug. However, ex vivo studies can only be performed using cross-sectional designs. Small-animal imaging offers the opportunity to perform serial assessments. We evaluated whether high-resolution pinhole single photon emission computed tomography (SPECT) imaging in rats was able to reproduce previous ex vivo findings.MethodsRats were imaged for baseline striatal DRD_2/3 availability using ultra-high-resolution pinhole SPECT (U-SPECT-II) and [¹²³I]IBZM as a radiotracer, and randomized to varenicline (n=7; 2 mg/kg) or saline (n=7). Following 2 weeks of treatment, a second scan was acquired.ResultsSignificantly increased striatal DRD_2/3 availability was found following varenicline treatment compared to saline (time?treatment effect): posttreatment difference in binding potential between groups corrected for initial baseline differences was 2.039 (P=.022), indicating a large effect size (d=1.48).ConclusionsUltra-high-resolution pinhole SPECT can be used to assess varenicline-induced changes in DRD_2/3 availability in small laboratory animals over time. Future small-animal studies should include imaging techniques to enable repeated within-subjects measurements and reduce the amount of animals.