Vagal-enteric interface: vagal activation-induced expression of c-Fos and p-CREB in neurons of the upper gastrointestinal tract and pancreas

Many gastrointestinal and pancreatic functions are under strong modulatory control by the brain via the vagus nerve. To start identifying location and neurochemical phenotype of the enteric neurons receiving functional vagal efferent input, we activated vagal preganglionic neurons either by electrical or chemical stimulation and examined the expression of phosphorylated CREB (c-AMP response element binding protein) and the immediate early gene c-Fos. There was no spontaneous expression of both markers in the pancreas and considerable spontaneous expression of p-CREB but not Fos in the upper GI-tract. Unilateral electrical vagal stimulation-induced p-CREB was found in 40% of neurons in the head of the pancreas. Fos expression was found in 70-90% of neurons in the esophagus and stomach, in 20-30% of myenteric plexus neurons and 5-15% in submucosal neurons of the proximal duodenum. Double-labeling experiments showed that a majority of pancreatic neurons and about 25-35% of neurons in the stomach and duodenum contain NADPH-diaphorase and that many of these receive functional vagal input. Other neurons that can be vagally activated contain gastrin-releasing peptide or calretinin. Chemical stimulation of the dorsal surface of the caudal brainstem with the stable TRH analog RX77368 resulted in selective activation of vagal efferents with expression of Fos in a small number of gastric myenteric plexus neurons. The results demonstrate the suitability of this method to investigate magnitude and local distribution of vagal input to the enteric nervous system as well as specificity of its neurochemically coded pathways. They represent the first step in the identification of function-specific units of parasympathetic vagal outflow.     

下颌骨的应力迹线与骨小梁构筑的关系

根据下頜光弹的等倾线图,描绘出主应力迹线规迹。在下颌侧位X线照片和去除唇侧及颊侧密质骨板的标本上,观察骨密质和松质的配布,以及骨小梁的排列和方向,试行探讨骨小梁方向与主应力迹线的关系。用光弹法求得的主应力迹线有两个系列:S_1系在下颌体近水平方向,在下颌支近垂直方向分布;S_2系力线与S_1系诸力线呈正交。在标本和X线照片上,主应力迹线规迹不同程度地在骨小梁的排列上有所反映。     

The incidence and clinical implications of hypersensitivity to papain in an allergic population, confirmed by blinded oral challenge

Five hundred allergy clinic patients were prick skin tested with papain, 1 mg/mL, in addition to usual local aeroallergens. Five of 475 subjects with seasonal allergic disease had positive skin tests to both papain and local pollens. None of the 25 individuals with negative skin test to pollens had skin reactivity to papain. The five subjects with positive skin tests to papain underwent double-blind placebo-papain challenges. All papain challenges were positive. Placebo challenges were negative. Papain-induced symptoms included palatal itching, watering itchy eyes, sneezing, rhinorrhea, abdominal cramps, diarrhea, and diaphoresis. Circulating papain-specific IgE was detected in all the papain-sensitive individuals, but not in control subjects. Confirmed papain sensitivity occurred in 1.05% of allergic subjects. In the papain-sensitive patients, cross-reacting antibodies with chymopapain were found. The small number of non-allergic subjects did not show any papain or chymopapain sensitivity in vitro.     

交互信息在心脏状态和心率研究中的应用

交互信息是一种检测系统之间相依性的方法 ,它可以同时检测线性和非线性相关。本文介绍了交互信息的计算方法和性质 ,讨论了它在单个时间序列上的应用 ,并将它应用于心脏状态研究上。利用实验动物的数据 ,我们发现了心搏的运动既不是随机的也不是周期的 ;并且 ,不同心脏状态下的交互信息有很大的差别 ,浅麻 ,机控呼吸和开胸状态下交互信息都相对较小 ,心肌损伤后有明显增大 ,提示心搏的交互信息与心脏健康程度有很大关系     

Bone-particle-impregnated bone cement: an in vivo weight-bearing study

To evaluate an experimental inorganic-bone-particle-impregnated bone cement, canine hip prostheses were implanted in dogs using a regular bone cement on one side and the experimental bone cement on the other. In a preliminary feasibility study, bone ingrowth into the resorbed bone-particle spaces was established 3 months after implantation in three dogs. In a more detailed study, twenty-eight (28) dogs were divided in four groups to delineate the effects of time on the phenomena of bony ingrowth. One month after implantation, active bone ingrowth into the bone cement was obvious. By 3 months postimplantation, the ingrowth appeared to have traversed the thickness of the bone-particle-impregnated cement. By the fifth month, most of the interconnected inorganic bone particles were replaced by new bone. At the end of a year, the ingrown bone was mature and negligible new bone activity was present. Biomechanical pushout tests closely corroborated the histologic observations. The maximum shear strength of the cement/bone interface of the experimental side reached 3.6 times that of the control side at 5 months postimplantation. No further improvements were seen at 12 months postimplantation. A viable bone/cement interface may result in a better orthopedic implant fixation system by combining the advantages of both cement for immediate rigidity and biological ingrowth for longterm stability.     

Proteomic analysis of human skin fibroblasts grown on titanium: novel approach to study molecular biocompatibility

Despite the growing use of titanium as an implant material, there is a lack of consensus on what constitutes the molecular basis of its biocompatibility. In the present study we compared the response of skin fibroblasts to two different growth supporting surfaces: commercially pure titanium (cpTi) and tissue culture polystyrene (TCPS). Proteins from extracts of whole cells and adsorbed serum were separated and identified by 2-dimensional gel electrophoresis. In all, 40 proteins (46 spots) were identified by matrix-assisted laser desorption/ionization and mass spectrometry, database searching, immunoblotting, running a standard, or a combination of these techniques. Many of the proteins collected from the two surfaces were found to derive from the serum used in the culture medium. The surface properties of titanium appeared to promote the formation of a more concentrated carpet of serum proteins. Several proteins from bovine or human serum, such as albumin, alpha2-HS-glycoprotein, alpha-fetoprotein, plasminogen, thrombospondin 1, and serotransferrin, along with a few unidentified serum components, were found to adsorb onto cpTi in comparatively high concentrations. The adsorption of serum proteins did not appear to be selective on either substrate. We found that among the major cellular proteins, fibronectin and a cytoskeletal protein (non-muscle myosin heavy chain type A) were expressed at lower levels by fibroblasts grown on cpTi compared to TCPS. By analyzing the changes in the entire proteome of cells in response to different growth substrates, we may gain a better understanding of the molecular basis of biocompatibility.     

多发性骨髓瘤患者血清IL-6活性与急性相蛋白浓度的相关性研究

运用敏感的B_9细胞增殖试验检测了81例多发性骨髓瘤(MM)患者血清IL-6活性,同时分析了标本的几种急性相蛋白含量,结果表明,68％MM患者血清中IL-6活性大于5μ/ml(正常对照为5μ/ml以下),几种急性相蛋白中C-反应性蛋白(CRP)在MM时升高(P<0.01),平均达正常对照组的17倍以上,MM患者补体C_4与正常对照组无差异(p>0.05),C_3、白蛋白及转铁蛋白在MM时分别比正常下降24.42％、38.83％和32.80％,且与疾病分期有关,在血清IL-6大于5μ/ml的55例中,IL-6活性与CRP、C_3、白蛋白的相关系数分别为0.46,-0.34和-0.29,IL-6与转铁蛋白浓度相关不明显。本文结果提示:CRP、C_3及白蛋白等含量的变化可作为反映MM病情的简易而敏感的指标。     

Favorably tipping the balance between cytopathic and regulatory T cells to create transplantation tolerance

Therapeutic application of broadly reactive anti-T cell antibodies can lead not only to potent immunosuppression but also to profound and long-lived T cell depletion. We reasoned that a strategy that almost exclusively targets activated cytopathic donor reactive T cells and spares immunoregulatory networks might prove to be an exceptionally potent and highly selective means of producing long-term engraftment and tolerance. Herein we show that the combined administration of rapamycin and agonist IL-2- and antagonist IL-15-related cytolytic fusion proteins provides for long-term engraftment/tolerance in exceptionally stringent allotransplant models by (1) limiting the early expansion of activated T cells, (2) preserving and even exaggerating their subsequent apoptotic clearance, and (3) further amplifying the depletion of these activated T cells by antibody-dependent mechanisms, while (4) preserving CD4+CD25+ T cell-dependent immunoregulatory networks.