Vascular adhesion protein 1 (VAP-1) mediates lymphocyte subtype-specific, selectin-independent recognition of vascular endothelium in human lymph nodes

Interactions between lymphocyte surface receptors and their ligands on vascular endothelial cells regulate the exit of lymphocytes from the circulation. Distinct subsets of mononuclear cells bind to high endothelial venules (HEVs) in different lymphoid organs to a different extent, but the molecular mechanisms behind this selectivity have remained poorly characterized. Here we show that vascular adhesion protein-1 (VAP-1) mediates subtype-specific binding of CD8-positive T cells and natural killer cells to human endothelium. VAP-1-dependent, oligosaccharide-dependent peripheral lymph node (PLN) HEV adhesion under shear was independent of L-selectin, P-selectin glycoprotein ligand 1, and alpha4 integrins, the known lymphocyte receptors involved in the initial recognition of endothelial cells. PLN HEV adhesion was also critically dependent on peripheral lymph node vascular addressins (PNAds), but lymphocyte L-selectin was absolutely required for PNAd binding. Most lymphocytes relied on both PNAd and VAP-1 in HEV binding. The overlapping function of L-selectin ligands and VAP-1 in PLN introduces a new control point into the lymphocyte extravasation process. Finally, intravital microscopy revealed that VAP-1 is involved in initial interactions between human lymphocytes and endothelial cells in inflamed rabbit mesenterial venules in vivo. In conclusion, VAP-1 is a novel contact-initiating ligand that discriminates between different subpopulations of mononuclear cells and is an appealing target for selective modulation of adhesion of CD8- and CD16-positive effector cells.     

Enalapril prevents imminent and reduces manifest cerebral edema in stroke-prone hypertensive rats

BACKGROUND AND PURPOSE: Stroke-prone spontaneously hypertensive rats (SHRSP), subjected to high NaCl intake, show severe hypertension, organ damage, and early death. Preventive treatment with an angiotensin-converting enzyme (ACE) inhibitor is known to reduce mortality. Previously we found that proteinuria always precedes cerebral edema in SHRSP. Hence, in this study ACE inhibition was started later, ie, directly after manifestation of either proteinuria or cerebral edema. METHODS: SHRSP were subjected to 1% NaCl intake. Group 1 served as a control. In group 2 early-onset treatment with the ACE inhibitor enalapril was initiated after proteinuria was >40 mg/d. In group 3 late-onset ACE inhibition was started after the first observation of cerebral edema with T2-weighted MRI. Cerebral edema was expressed as the percentage of pixels with an intensity above a defined threshold. RESULTS: In controls median survival was 54 days (range, 32 to 80 days) after start of salt loading. The terminal level of cerebral edema was 19.0+/-3.0%. Under early-onset enalapril, median survival increased to 320 days (range, 134 to 368 days; P<0.01 versus group 1). Cerebral edema was prevented in all but 1 rat. Systolic blood pressure was slightly and transiently reduced at day 14. Proteinuria was markedly reduced (52+/-7 versus 190+/-46 mg/d in group 1 at day 7; P<0.05). Under late-onset enalapril, median survival was 264 days (range, 154 to 319 days; P<0.01 versus group 1). Cerebral edema decreased to baseline levels (9.6+/-2.9 at day 0 to 3.4+/-0.5% at day 3; (P<0.05). Ultimately cerebral edema reoccurred in 6 of the 8 rats. SBP decreased slightly at day 7 only. Proteinuria decreased from 283+/-27 at day 0 to 116+/-22 mg/d at day 7 (P<0.05). Complete remission of the original locus of cerebral edema was confirmed histologically. CONCLUSIONS: In SHRSP with proteinuria, treatment with an ACE inhibitor both prevented the development of cerebral edema and reduced manifest cerebral edema and proteinuria. Survival was markedly prolonged. These findings support the use of ACE inhibition for treatment in hypertensive encephalopathy.     

Heat-Shocked Lactobacilli for Acceleration of Cheddar Cheese Ripening

The aim of this study was to establish adequate conditions for heat-shocking cells of lactobacilli, to sufficiently suppress lactic acid production without damaging the proteolytic enzyme system important for cheese maturation. Three temperatures, 65, 67 and 70°C were tested, for 22 sec. The best combination for maximum retardation of lactic acid production and minimum damage to the proteolytic system was obtained by treating cells at 67°C for 22 sec. Following such treatment, lactic acid production was retarded by 24 hr, while the proteolytic enzyme system remained scarcely unchanged.     

弱交流磁场下裸铜表面结晶特性研究

本文研究了环境温度恒定为25℃、相对湿度为49%、体积为0. 01 m L的液滴在-20℃裸铜底板的冻结实验,发现在附加交流磁场强度分别为2. 0×10^-3、2. 5×10^-3、3. 0×10^-3、3. 5×10^-3、4. 0×10^-3、4. 5×10^-3、5. 0×10^-3、5. 5×10^-3、6. 0×10^-3T的作用下,液滴结晶过冷度增大,最大过冷度提高了2. 08℃;但附加磁场会减小成核驱动力;相比无磁场情况下,液滴冷凝时间减少,凝结粒径相比无磁场下较小。通过对在相同温湿度下自然对流条件的冷铜底板结霜可视化研究发现,由于附加磁场使极性水分子有序的在底板排列,较无磁场下液滴结晶过程熵增更小,在宏观上呈现液滴有序排列。此外,实验发现在0～6×10^-3T的磁场强度范围,随着磁场强度的增大,平板单位面积结霜量减小,单位面积结霜量与交流磁场强度有较高的相关性,得到了拟合关...     

Gap junction disappearance in astrocytes and leptomeningeal cells as a consequence of protozoan infection

Trypanosoma cruzi and Toxoplasma gondii are protozoan parasites capable of causing infections of the nervous system. In order to determine effects of infection by these organisms on intercellular communication in the brain, dye coupling and connexin abundance and distribution were examined in leptomeningeal cells and astrocytes infected with T. cruzi or T. gondii. For both cell types infected with either type of protozoan parasite, intercellular diffusion of intracellularly injected Lucifer Yellow was dramatically reduced. Immunocytochemistry with antibodies specific for connexin43 (in astrocytes) or both connexin43 and connexin26 (for leptomeningeal cells) demonstrated that punctate gap junctional staining was much reduced in infected cells, although uninfected neighbors could display normal connexin abundance and distribution. Western blot analyses revealed that connexin43 abundance in both cell types infected with either parasite was similar to that in uninfected cells. Phosphorylation state of connexin43 (inferred from electrophoretic mobility of connexin43 isoforms) was not significantly affected by the infection process. Immunocytochemistry of whole brains from animals acutely infected with either parasite also showed a marked reduction in connexin43 expression. We conclude that infection of both types of brain cells with either protozoan parasite results in a loss of intercellular communication and organized gap junction plaques without affecting expression levels or posttranslational processing of gap junction proteins. Presumably, these changes in gap junction distribution result from altered targeting of the junctional protein to the plasma membrane, and/or from changes in assembly of subunits into functional channels.     

Chitosan Coating Effect on Storability and Quality of Fresh Strawberries

The effect of chitosan coating (1.0 and 1.5% w/v) in controlling decay of strawberries at 13°C was investigated as compared to a fungicide, iprodione (Rovral®). Chitosan coating significantly reduced decay of berries (P ≤ 0.05) compared to the control. There was no significant difference between chitosan and fungicide treatments up to 21 days storage. Thereafter, Rovral®-treated berries decayed at a higher rate than chitosan-coated berries. Chitosan-coated berries stored at 4°C were firmer, higher in titratable acidity, and synthesized anthocyanin at a slower rate than Rovral®-treated or nontreated berries. Chitosan coating decreased respiration rate of the berries with a greater effect at higher concentration.     

Concentrations of some trace elements in hair, liver and kidney from autopsy subjects--relationship between hair and internal organs

Autopsy samples of hair, liver and kidney cortex from 30 Swedish subjects (Caucasian) were analysed for Ag, Co, Cr, Hg, Sb, Se and Zn by neutron activation analysis (NAA). The following elements were observed to have higher concentrations in hair than in liver and kidney cortex: Ag, (Co), Cr and Hg (on a dry weight basis). Selenium was highly concentrated in kidney cortex, and Fe in liver. The observed concentrations of most of the elements were very variable for each tissue. In particular, Co values for hair showed more than a 5000-fold difference. However, Se values for hair were relatively constant. A highly significant positive correlation was observed between Hg concentrations in hair and kidney cortex. Somewhat weaker correlations were found between Hg in kidney cortex and liver and Se in hair and kidney cortex. The concentration of Co in liver correlated with that in kidney cortex. It was concluded that, with the exception of mercury, and to a lesser degree selenium, hair analysis did not provide a useful measure of the trace element status of the subjects included in this study.     

Work conditions, mastery and psychological distress: are housework and paid work contexts conceptually similar?

This research examined how the conditions of paid work and unpaid housework were related to women's sense of mastery, depressed mood and anxiety. The data for these analyses were taken from the American Changing Lives (ACL) survey (House, 1986). This research draws from a subsample of 992 black and non-Hispanic white women aged 24 to 59. The conditions of work on the job and in the home are not consistently related to women's psychological functioning. Among employed women, decision latitude on the job is related to depressed mood indirectly through their sense of mastery; the physical demands of work are directly related to depressed mood, but the effect is stronger among employed women than employed homemakers. In contrast, decision latitude at home is directly related to depressed mood among homemakers; the physical demands of housework are related to depressed mood only indirectly through women's sense of mastery. This pattern is repeated in the relationship between anxiety and decision latitude both at home and on the job, and in the relationship between anxiety and physical demands of work on the job. Both unpaid housework and paid work are forms of productive activity, but these findings suggest they are not a ubiquitous entity with similar effects for all women. Rather the context of work shapes the effect of work conditions for women's psychological functioning.