Characterization of FcepsilonRI-bearing CD123 blood dendritic cell antigen-2 plasmacytoid dendritic cells in atopic dermatitis

BACKGROUND: The high-affinity receptor for IgE (FcepsilonRI) on myeloid dendritic cells has been shown to play a major role in atopic dermatitis (AD). Plasmacytoid dendritic cells (pDCs), which are instrumental in the defense of viral infections, are present in reduced amounts in the skin of patients with AD, which is characterized by a high susceptibility to viral infections. OBJECTIVE: We explored phenotypical and functional characteristics of pDC in the peripheral blood of patients with AD and healthy individuals. METHODS: Blood dendritic cell antigen-2+CD123+ pDCs were enriched from the peripheral blood of patients with AD and studied in functional assays. RESULTS: Skin-homing molecules such as cutaneous lymphocyte antigen and L-selectin CD62L were expressed in lower levels on pDCs of patients with AD. pDCs expressed high amounts of IgE-occupied FcepsilonRI. Further, FcepsilonRI aggregation on pDCs impaired the surface expression of MHC I and II, induced the production of IL-10, and enhanced the apoptosis of pDCs. Importantly, FcepsilonRI preactivated pDC produced less IFN-alpha and IFN-beta after stimulation with CpG motifs and enhanced the outcome of immune responses of the TH2 type. CONCLUSION: From these data, we conclude that FcepsilonRI-bearing pDCs from patients with AD (1) are different from pDCs of healthy individuals, (2) might be important in the pathophysiology of AD, and (3) contribute to the enhanced susceptibility of patients with AD to viral infections.     

Blood glucose measurement by infrared spectroscopy

For the development of an implantable artificial endocrine pancreas, a sensor for blood glucose measurement is needed providing a long-term stability. This goal can be achieved by the application of infrared spectroscopy which, unlike electrochemical sensors, responds directly to the glucose molecule. An investigation under physiological conditions revealed five glucose absorption bands in the near and middle infrared range. These are 1040, 1085, 1109, 1160 and 1365 cm-1. Only the 1040 cm-1 frequency coincides with none of the other infrared-active blood substances like proteins, lipids and urea. Nevertheless, the other absorption bands too, especially the 1109 cm-1 frequency, can be used for blood glucose measurement, if the superimposed absorptions are compensated. Methods for the compensation have been found. Technically feasible embodiments of an infrared glucose sensor are described.     

Mitoxantrone: Propensity for free radical formation and lipid peroxidation — implications for cardiotoxicity

Summary Results of comparative studies on stimulation of the rates of cofactor consumption, superoxide generation and hydrogen peroxide production by mitoxantrone (Novantrone®; dihydroxyanthracenedione; MXN), ametantrone (AM), doxorubicin (DOX) and daunorubicin (DNR) in the presence of NADPH-cytochrome P-450 reductase, NADH dehydrogenase, or rabbit hepatic microsomes have been reported. MXN and AM were substantially less effective in stimulating the rate of cofactor oxidation, superoxide formation or hydrogen peroxide production relative to the anthracyclines. In the presence of P-450 reductase, the rate of NADPH oxidation or superoxide generation produced by 100 M MXN or AM was only 15% and 2% respectively of that produced by 100 M anthracycline.The effects of MXN and AM on lipid peroxidation in hepatic microsomes, cardiac sarcosomes and cardiac mitochondria were determined and compared with those produced by ADM. MXN and AM at 50 M inhibited the basal rate of NADPH-dependent rabbit liver microsomal lipid peroxidation by 50%; in contrast, DOX enhanced the rate of hepatic microsomal lipid peroxidation by 2-and 2.5-fold at 100 and 200 M, respectively. Rabbit cardiac sarcosomal NADPH-dependent lipid peroxidation was inhibited completely at 100 M anthracenedione. NADH-dependent lipid peroxidation in cardiac mitochondria was diminished by 50 M MXN and AM, whereas 50 M DOX produced a 2-fold stimulation in lipid peroxidation. The anthracenediones also effectively inhibited DOX-stimulated lipid peroxidation with 50% inhibition occurring at 4 M (MXN) and 6 M (AM). Moreover, both MXN and AM potently inhibited iron (100 M)-stimulated lipid peroxidation in rabbit hepatic microsomes with 80% inhibition produced by 15 M anthracenedione.These results are consistent with the diminished cardiotoxicity of mitoxantrone and ametantrone relative to DOX or DNR and may require a reassessment of the role of lipid peroxidation in the mechanism(s) of quinone antineoplastic agent-mediated cardiotoxicity.     

Induction of rat liver microsomal epoxide hydrolase by thiazole and pyrazine: hydrolysis of 2-cyanoethylene oxide

Liver microsomal epoxide hydrolase (mEH) is active in the detoxificationof epoxide-containing carcinogens. The effects of thiazole andpyrazine, constituents of tobacco and tobacco smoke as wellas of a variety of foods, on the expression and regulation ofmEH were examined in rats (200 mg/kg body wt/day, i.p., 1/emdash3 days). Immunoblot analyses using rabbit anti-rat mEH antibodyrevealed a significant increase in mEH levels in hepatic microsomesisolated from either thiazole- or pyrazine-treated animals.Another protein (43 kd) cross-reacting with polyclonal mEH antibodywas found to be increased concomitantly following pyrazine treatment.Northern and slot blot analyses showed substantial increasesin mEH mRNA following either thiazole or pyrazine treatment.The level of mEH mRNA increased 17-fold at 24 h following thiazoletreatment, relative to control. Approximately 20- and 16-foldincreases in mEH mRNA were also observed at 48 and 72 h respectivelyfollowing treatment with pyrazine. The level of polymerase chainreaction (PCR)-amplified mEH DNA derived from poly(A)+ RNA wasclearly elevated following either thiazole or pyrazine treatmentrelative to that from untreated animals. Both sense and antisensestrands of PCR-amplified mEH DNA were cloned into an M13mpl9phage vector in order to examine the nucleotide sequences ofPCR-amplified mEH DNA derived from the poly(A)+ RNA isolatedfrom thiazole- or pyrazine-treated animals. Sequence analysesrevealed that the sequence of PCR-amplified DNA from the inducedmRNA was identical to that published for mEH cDNA. Epoxide hydrolaseactivity toward the hydrolysis of 2-cyanoethylene oxide (CEO),the epoxide metabolite of the rat carcinogen acrylonitrile,was not significant in hepatic microsomes from untreated rats,but was substantially induced by treatment with thiazole orpyrazine. Microsomal hydrolysis activity was heat-sensitiveand potently inhibited by l, l, l-trichloropropene-2, 3-oxide,indicating that mEH was the catalyst. The V_max for the hydrolysisof CEO by hepatic microsomes from thiazole-treated rats (13.4nmol/min/mg protein) was 1.5-fold greater than that with microsomesfrom pyrazine-treated rats, whereas similar K_m values ( 1 mM)were observed for both microsomal preparations. These kineticdata correlate well with the increases in mEH mRNA observedafter administration of thiazole or pyrazine to rats. Theseresults provide evidence that administration of thiazole orpyrazine induces mEH with a large increase in mEH mRNA, andthat the induced mEH catalyzes the hydrolysis of CEO.     

Fos expression in the sleep-active cell group of the ventrolateral preoptic area in the diurnal murid rodent, Arvicanthis niloticus

The ventrolateral preoptic area (VLPO) of the nocturnal laboratory rat receives direct input from the retina and is active during sleep; however, nothing is known about VLPO function in day-active (diurnal) species. In the first study, we used 24-h videotaping of Arvicanthis niloticus, a diurnal murid rodent, to estimate the distribution of sleep and wakefulness across a 12:12 light-dark cycle. Based on behavioral data, A. niloticus were perfused at a time when the animals are inactive (zeitgeber time (ZT) 20) or at a time when they are awake and active (ZT 23). The brains were processed for immunocytochemistry for Fos, an immediate early gene product used as an index of neural activity. Animals had more Fos-immunoreactive (Fos+) cells in the VLPO at ZT 20 than at ZT 23. The pattern of change in Fos expression seen in this area suggest that the VLPO serves the same function in A. niloticus as in rats. Eye injections of cholera toxin (beta subunit) were used to identify the retinal inputs to the VLPO of A. niloticus. In these animals, the VLPO had only very sparse retinal inputs compared to the rat. Together, these results raise the possibility that inputs from the suprachiasmatic nucleus (SCN) or the retina affect neuronal activity in the VLPO differently in rats and A. niloticus, thereby, contributing to differences in their sleep/wake patterns.     

Enteral nutrition in intensive care patients: a practical approach.

Severe protein-calorie malnutrition is a major problem in many intensive care (ICU) patients, due to the increased catabolic state often associated with acute severe illness and the frequent presence of prior chronic wasting conditions. Nutritional support is thus an important part of these patient's management. Over the years, enteral nutrition (EN) has gained considerable popularity, due to its favorable effects on the digestive tract and its lower cost and rate of complications compared to parenteral nutrition. However, clinicians caring for ICU patients are often faced with contradictory data and difficult decision-making when having to determine the optimal timing and modalities of EN administration, estimation of patient requirements and choice of formulas. The purpose of this paper is to provide practical guidelines on these various aspects of enteral nutritional support, based on presently available evidence.     

去甲硫氨酸全肠外营养对大鼠血清氨基酸谱的影响

目的观察去甲硫氨酸全肠外营养对大鼠血清氨基酸谱等的影响.方法 Wistar大鼠24只,随机分为含甲硫氨酸(+MetTPN,n=12)和去甲硫氨酸全肠外营养2组(-MetTPN,n=12),分别给予相应的TPN支持.治疗7d后,每组随机抽取6只大鼠处死,检测血清FAA(HPLC法)、肝肾功能和全血常规,同时作心、肺、肝、肾组织病理学检查.两组其余大鼠继续原TPN治疗,观察生存期.结果 -MetTPN组大鼠血清游离Met、Cys明显降低,Asp、Glu、Ser等显著增高;大鼠体重下降;血清总蛋白和白蛋白水平下降;血常规和肾功能未见明显异常;组织学检查见肝细胞轻度肿胀,细胞核仁增粗,心肺肾未见明显异常;平均生存18d.对照组上述检查未见异常,除一只大鼠因导管并发症于TPN第16d死亡,其余大鼠全部存活.结论 -MetTPN一周可致大鼠血清游离Met、Cys明显降低和Asp、Glu、Ser等显著增高,及轻度肝功能改变;随着-MetTPN时间延长,出现严重的代谢紊乱和器官功能障碍导致死亡.