Spatially patterned gene expression for guided neurite extension

Axon pathfinding by localized expression of guidance molecules is critical for the proper development of the nervous system. In this report, we present a well-defined spatially patterned gene expression system to investigate neurite guidance in vitro. Nonviral gene delivery was patterned by combining substrate-mediated gene delivery with soft lithography techniques, and the amount of protein produced at the region of localized expression was varied by altering the vector concentration and the width of the pattern, highlighting the flexibility of the system. A neuronal coculture model was used to investigate responses to spatial patterns of nerve growth factor (NGF) expression. The soluble NGF gradient elicited a guidance cue, and the degree of guidance was governed by the distance a neuron was cultured from the pattern and the time between accessory cell and neuron seedings. A portion of the diffusible NGF bound to the culture surface in the extracellular space, and the surface-associated NGF supported neuron survival and neurite outgrowth. However, the surface-bound NGF gradient alone did not elicit a guidance signal, and in fact masked the guidance cue by soluble NGF gradients. Mathematical modeling of NGF diffusion was used to predict the concentration gradients, and both the absolute and fractional gradients capable of guiding neurites produced by patterned gene expression differed substantially from the values obtained with existing engineered protein gradients. Spatially patterned gene expression provides a versatile tool to investigate the factors that may promote neurite guidance.     

氧化苦参碱对免疫功能低下小鼠免疫功能的影响

目的观察氧化苦参碱对免疫低下小鼠免疫功能的影响,寻找氧化苦参碱治疗慢性乙型肝炎的可能机制．方法采用环磷酰胺建立免疫低下小鼠模型,小鼠腹腔注射氧化苦参碱后,观察氧化苦参碱对小鼠网状内皮系统吞噬廓清能力、对T淋巴细胞酯酶染色率、对二硝基氯苯所致迟发型超敏反应的影响和对小鼠血清溶血素抗体的影响．结果氧化苦参碱能抑制T淋巴细胞酯酶染色率,增强网状内皮系统的吞噬能力,但对迟发型超敏反应和血清溶血素抗体无明显影响．结论氧化苦参碱对免疫低下小鼠的细胞免疫具有明显抑制作用,并能增强其非特异性免疫．     

Hemofiltration and immune response in severe sepsis

BACKGROUND: Levels of pro- and anti-inflammatory cytokines have been determined in numerous investigations. However, measurements of isolated cytokines do not allow conclusions on the resulting immune state. The purpose of this study was to determine resulting immune functions in patients' plasma. Additionally, similar measurements were performed with ultrafiltrate gained from continuous venovenous hemofiltration (CVVH). MATERIALS AND METHODS: Nine septic patients and six critically ill patients with renal dysfunction in a surgical intensive care unit were observed. Two immune functions were chosen for detailed investigation over a time period of 72 h. The ability of patients' plasma to induce or suppress beta(2)-integrin expression on neutrophils of healthy controls served as marker for leukocyte activation. Interleukin (IL)-6 production or inhibition in washed whole blood cells induced through patients' plasma was used as a marker of cytokine secretion. RESULTS: Plasma from septic patients led to a constantly increased expression of beta(2)-integrins on isolated, unstimulated neutrophils. At the same time, septic plasma permanently suppressed the production of IL-6 and IL-10 in stimulated whole blood. Ultrafiltrate from CVVH mirrors the equivalent immune response patterns found for plasma. We did not find significant differences pre- and postfilter or over the next 72 h in the potential to cause IL-6 and IL-10 production or beta(2)-integrin expression. CONCLUSIONS: Plasma from septic patients triggers an increased expression of adhesion molecules and inhibited secretion of IL-6 and IL-10 in stimulated whole blood cells compared with nonseptic critically ill patients. Moreover, CVVH withdraws triggering mediators from plasma in equally bioactive proportions.     

Live imaging of amyotrophic lateral sclerosis pathogenesis: Disease onset is characterized by marked induction of GFAP in Schwann cells

Amyotrophic lateral sclerosis (ALS) is a late‐onset neurological disease characterized by progressive loss of motor neurons. At present, the pathological events precipitating disease onset and the exact pattern of disease progression are not fully understood. Recent studies suggest that glial cells, in particular activated astrocytes, can release factors that can directly kill motor neurons. To further investigate the involvement of glial cells (astrocytes and Schwann cells) in the pathogenesis of ALS, we generated ALS‐(GFAP‐luciferase/SOD^G93A) reporter mouse in which upregulation of glial fibrillary acidic protein (GFAP) can be visualized from live animals throughout the different stages of disease. Our results suggest that the disease in mice is initiated simultaneously in the spinal cord and in the peripheral nerves and is characterized by several cycles of GFAP upregulation. Immunohistochemical analysis confirmed that the induction GFAP bioluminescence signals were associated with the significant increases in GFAP immunoreactivity. The first pathological GFAP signals occurring at 25–30 days were asymptomatic and detectable at the level of lumbar spinal cord projections and at the periphery. These early events were then followed by GFAP promoter inductions that were associated with the distinct clinical symptoms. As expected, the onset of paralysis (112 days) was associated with the gradual and marked GFAP upregulation in the spinal cord. Interestingly, however, the disease onset (90 days) was characterized by sharp and synchronized induction of GFAP in peripheral nerve Schwann cells suggesting that peripheral nerves pathology/denervation and associated Schwann cell stress may play an important role in the ALS pathogenesis. © 2008 Wiley‐Liss, Inc.     

Essential oil of clove (Eugenia caryophyllata) augments the humoral immune response but decreases cell mediated immunity

The present study was undertaken to explore the effect of the essential oil isolated from the buds of Eugenia caryophyllata on some immunological parameters. Humoral immunity was assessed by measuring the hemagglutination titre to sheep red blood cells and delayed type hypersensitivity was assessed by measuring foot pad thickness. Clove oil administration produced a significant increase in the primary as well as secondary humoral immune response. In addition, it also produced a significant decrease in foot pad thickness compared with the control group. Thus, these results suggest that clove oil can modulate the immune response by augmenting humoral immunity and decreasing cell mediated immunity.     

Comparison of humoral and cellular immune responses to a pentavalent modified live virus vaccine in three age groups of calves with maternal antibodies,before and after BVDV type 2 challenge

The aim of this study was to evaluate the ability of a pentavalent (BVDV types 1 and 2, BHV-1, BRSV, and PI-3) modified live virus (MLV) vaccine given to 1–2-, 4–5-, and 7–8-week-old calves with maternal antibodies to induce humoral and cellular immune responses and protect calves from virulent BVDV type 2. Eight calves in each age group were vaccinated and four served as controls. All calves were challenged intranasally with BVDV type 2, 12 weeks after vaccination. SVN titers to all five viruses declined in all groups after vaccination (except 4–5-week-old calves to BVDV type 1). After challenge, the SVN titers for both types of BVDV showed anamnestic responses in calves vaccinated at 4–5 and 7–8 weeks, but not at 1–2 weeks of age. In all groups, T cell subsets responded specifically to BVDV types 1 and 2 but not to BHV-1, BRSV, or PI-3 after vaccination by increasing their expression of activation markers (CD25, IFN-γ and IL-4). All vaccinated calves were significantly protected from BVDV type 2 challenge.     

Human papillomavirus 16 L1-E7 chimeric virus like particles show prophylactic and therapeutic efficacy in murine model of cervical cancer

Cervical cancer is found to be associated with human papillomavirus (HPV) infection, with HPV16 being the most prevalent. An effective vaccine against HPV can thus, be instrumental in controlling cervical cancer. An ideal HPV vaccine should aim to generate both humoral immune response to prevent new infection as well as cell-mediated immunity to eliminate established infection. In this study, we have generated a potential preventive and therapeutic candidate vaccine against HPV16. We expressed and purified recombinant HPV16 L1(ΔN26)-E7(ΔC38) protein in E. coli which was assembled into chimeric virus like particles (CVLPs) in vitro. These CVLPs were able to induce neutralizing antibodies and trigger cell-mediated immune response, in murine model of cervical cancer, exhibiting antitumor efficacy. Hence, this study has aimed to provide a vaccine candidate possessing both, prophylactic and therapeutic efficacy against HPV16 associated cervical cancer.     

Study on the T-helper cell 1/2 cytokine profile in blister fluid of patients with herpes zoster and its clinical significance

Herpes zoster (HZ) is a Varicella zoster virus infection disease. Previous studies have presumed the connection between development of HZ and involvement of cellular immunity in peripheral blood. However, whether cellular immunity plays a role in the local skin lesion has not been addressed. To explore the levels of T-helper cell (Th)1/Th2 type cytokine profiles in the blister fluid of the skin lesions from the patients with HZ and its role in pathogenesis, we used the cytometric bead array kit to compare the levels of cytokines (interleukin [IL]-2, tumor necrosis factor [TNF]-α, IL-10 and IL-4) in blister fluid from 46 patients with those from the suction blister fluids from 20 volunteers without any infectious disease (the control group). The results indicated that the levels of Th1 cytokines, IL-2 and TNF-α in the blister fluid from the patients' skin lesions were significantly lower than those from the control group, whereas the levels of Th2 cytokines IL-10 and IL-4 were significantly higher than those in the control group. Moreover, significant variation of the levels of Th1/Th2 cytokines (IL-2, TNF-α, IL-10 and IL-4) in the blister fluid from the HZ patients' lesions was also observed among different stages of the disease. It is concluded that a cytokine imbalance was present in the local lesions of patients with HZ during disease development. Our data suggested that the Th immunity was associated with disease activity, which may play an important role in the pathogenesis of HZ.     

Evaluation of a Single Stage Nitroglycerin Tilt Table Test for Diagnosis of Neurally Mediated Syncope

The purpose of this study was to compare clinical outcomes between a single stage head-up tilt table test (HUT) with infusion of 3.44 microg/kg per hour of nitroglycerin and a conventional multistage test with infusion of nitroglycerin from 1.72 microg/kg per hour to 5.16 microg/kg per hour in five successive stages. Thirty-seven patients with recurrent syncope underwent both tests in a prospective, randomized, crossoverfashion. During single stage HUT, a positive response occurred in 24 (64.9%) patients with unexplained syncope, an exaggerated response occurred in 3 (8.1%), a negative response in 7 (18.9%), and drug intolerance in 3 (8.1%). During the multistage HUT, these percentages were 62.2%, 16.2%, 13.5%, and 8.1%, respectively. Twenty healthy control subjects were involved in both tests, One of the control subjects had a positive response to single stage HUT, and two (10%) patients to multistage HUT. The duration of the test in single stage HUT was shorter than that in multistage HUT (8.6 +/- 10.3 vs 38.6 +/- 32.1 minutes, P < 0.01). The results showed that the single stage HUT was a fairly sensitive, specific, and a time-efficient test for provoking neurally mediated syncope.