On-Chip Endothelial Inflammatory Phenotyping

Atherogenesis is potentiated by metabolic abnormalities that contribute to a heightened state of systemic inflammation resulting in endothelial dysfunction. However, early functional changes in endothelium that signify an individual''s level of risk are not directly assessed clinically to help guide therapeutic strategy. Moreover, the regulation of inflammation by local hemodynamics contributes to the non-random spatial distribution of atherosclerosis, but the mechanisms are difficult to delineate in vivo. We describe a lab-on-a-chip based approach to quantitatively assay metabolic perturbation of inflammatory events in human endothelial cells (EC) and monocytes under precise flow conditions. Standard methods of soft lithography are used to microfabricate vascular mimetic microfluidic chambers (VMMC), which are bound directly to cultured EC monolayers.¹ These devices have the advantage of using small volumes of reagents while providing a platform for directly imaging the inflammatory events at the membrane of EC exposed to a well-defined shear field. We have successfully applied these devices to investigate cytokine-,² lipid-^{3, 4} and RAGE-induced⁵ inflammation in human aortic EC (HAEC). Here we document the use of the VMMC to assay monocytic cell (THP-1) rolling and arrest on HAEC monolayers that are conditioned under differential shear characteristics and activated by the inflammatory cytokine TNF-α. Studies such as these are providing mechanistic insight into atherosusceptibility under metabolic risk factors.     

Localization of the gene for a third G protein β-subunit to mouse chromosome 6 near Raf-1

The large family of signal transducing proteins known as G proteins are heterotrimers that dissociate into an independent α-subunit and βγ-subunit complex after ligand binding or other stimulation. For Gα, at least 30 distinct sequences representing 10 different classes have been identified. On the other hand, cDNAs for only three Gβ-subunit genes have been isolated so far. All three of the Gβ genes have been chromosomally mapped in the human, but only two in the mouse. Using a human retinal cDNA for the third G protein β-subunit, we have mapped the corresponding gene, termed Gnb-3, to mouse Chromosome 6 with somatic cell hybrids and have positioned it distal to but near the marker Raf-1 by analysis of the progeny of three genetic crosses.     

Floral induction by gibberellic acid in Impatiens balsamina,a qualitative short-day plant

Summary In the qualitative short-day plant Impatiens balsamina, gibberellic acid (GA₃) not only promoted the formation of floral buds in response to suboptimal photoinductive conditions and reduced the number of SD cycles that are required for their development into flowers, but also caused initiation of floral buds under non-inductive photoperiods. In plants treated with repeated applications of GA₃, the floral buds developed into flowers irrespective of whether the apex was left intact or was removed. In those that received a single application of GA₃ the floral buds developed into flowers only in decapitated plants.     

A comparative study of the epidermis of the common carp and the three Indian major carp

A comparative study has been made of the mucogenic epidermis of the common carp, Cyprinus carpio var. communis, and the three Indian major carps, Catla catla, Labeo rohita and Cirrhina mrigala: on the basis of epidermis structural organization, these species are easily differentiated. The epithelial cells in the superficial layer, as in most fishes, show secretory activity, evidenced by positive histochemical reactions, which is high in C. carpio var. communis, moderate in C. catla and low in L. rohita and C. mrigala. The epithelial cells in the underlying two or three layers also give positive reactions, though their intensity is relatively weak. The mucous cells in C. carpio var. communis are distributed in large numbers arranged in several superimposed layers in the outer regions of the epidermis, whereas in C. catla they are fewer in number and are widely separated in the surface layers as well as in the deeper layers of the epidermis; in both species the mucous cells appear rounded, large, and open on the surface by wide pores. In contrast, in L. rohita and C. mrigala the mucous cells are smaller, restricted mainly to the superficial layer, close together in a single row, and open on the surface by narrow pores. The overall density of mucous cells in L. rohita and C. mrigala, as in C. catla, is much lower than in C. carpio var. communis. In the epidermis of C. carpio var. communis there are a large number of mucous cells, and the few club cells are restricted to the deeper layers. In contrast, in the epidermis of the three Indian major carp the overall density of the mucous cells is much lower and the club cells are very numerous. It is suggested that the high density of club cells compensates an overall low density of mucous cells as an adaptation for an effective defence mechanism. Increased mucus production in the epidermis of C. carpio var. communis, as evidenced by a large number of mucous cells in outer regions and high secretory activity of superficial layer epithelial cells, is associated with increased precipitation of mud held in suspension, needed as an adaptation to the species’peculiar bottom-scooping habits. The varied density of the taste buds in the epidermis of the four carp is associated with their feeding habits.     

A photomap of the salivary gland chromosomes of Anopheles stephensi liston (Culicidae: Diptera)

A photomap of the banding pattern of the salivary gland chromosomes of Anopheles stephensi Liston, which is first of its kind, has been prepared. The salivary chromosome complement consists of five arms, the shortest of which represents the telocentric X-chromosome, and the remaining four the autosomal arms. A comparison has been made of the banding pattern of this species with other species of the subgenus Cellia.     

Fatty acid activation of guanylate cyclase from fibroblasts and liver.

Sodium arachidonate and sodium oleate increased particulate guanylate cyclase activity from homogenates of Balb 3T3 cells or rat liver. The fatty acids were about equipotent and were maximally effective at about 100 μm concentrations. Higher concentrations were less effective or inhibitory. Activation was similar in an air or nitrogen atmosphere and was unaltered by KCN, aspirin, or indomethacin. The dose-response curve was shifted to the right when arachidonate was preincubated prior to its addition to guanylate cyclase assays. Agents that facilitate fatty acid oxidation and the formation of malonyldialdehyde during preincubation such as glutathione, hemoglobin, Mn²⁺, Fe³⁺, or lipoxygenase shifted the dose-response curve further to the right. In contrast, agents that decreased or prevented arachidonate oxidation and malonyldialdehyde formation during preincubation such as butylated hydroxyanisole, propyl gallate, hydroquinone, and diphenylfuran prevented the shift in the dose-response curve or in some instances shifted the dose-response curve to the left. Activation of guanylate cyclase by arachidonate was reversed by the addition of lipoxygenase to incubations. These studies indicate that unsaturated fatty acids and not their oxidation products activate particulate enzyme from Balb 3T3 cells. The mechanism of fatty acid activation appears to be different from activation by nitro compounds. Fatty acids but not nitro compounds activated fibroblast preparations, and the effect of fatty acids in contrast to the activation by nitroprusside in liver preparations was not prevented with Lubrol PX.     

Alterations of Phospholipid Metabolism in Rat Cerebral Cortex Mince Induced by Cationic Amphiphilic Drugs

Abstract Cationic amphiphilic drugs (CADs) of varied clinical use were screened to determine their capacity to alter the pattern of labeling with ³²Pj of cerebral cortex mince phospholipids. The altered phospholipid labeling patterns were qualitatively similar, the prominent features being reduced incorporation into phosphatidylcholine and increased incorporation into phosphatidic acid. Relative potencies were: (±)-propranolol > chlorpromazine = 4,4'-bis(diethylaminoethoxy) α,β -diethyldiphenylethane > desipramine > di-bucaine > pimozide > oxymetazoline = fenfluramine = haloperidol = chloroquine > amphetamine = no drug added. Propranolol was used to study the action of CADs further. Its effect was time- and dose-dependent, but in contrast with pineal gland, no label appeared in phosphatidyl-CMP (CDP-diacylglycerol), nor did dialysis of the mince to reduce diffusible substrates or exogenous addition of substrates cause appearance of liponucleotide. Thus lack of diffusible precursors is not responsible for CAD effects in vitro. Pulse-chase experiments with ³²P₁ and [2-³H]glycerol suggested that inhibition of phosphatidate phosphohydrolase may be partly responsible for the observed alterations in phospholipid labeling in the presence of CADs.     

Chemical equilibrium and E value of Zn (ZnE) in inceptisols and entisols of tropical india

Summary The chemical equilibrium and E value for Zn was calculated in 9 soils of Haryana (India) which represented mainly entisol and inceptisols. The rate of isotopic exchange between⁶⁵Zn and native soil Zn was quite rapid and radioactivity reduced to about 0.2 per cent of initial activity after 3 days but total Zn concentration in soil solution did not decrease. In 5 out of 9 soils equilibrium was established in 2 to 3 days. In typic ustochrepts having high clay content (3,4) equilibrium was attained in two days. In typic udipsamments (2), typic camborthids (8) and aquic vertic ustichrepts (9) it took 3 days to set equilibrium. Typic ustochrepts (5) took 5 days for equilibrium whereas typic ustipssaments (6) and typic camborthids of high O.C. did not attain equilibrium even in 7 days. This indicated that the chemistry and availability of Zn in soil would depend on soil types. When Zn_E was estimated by applying activity after equilibrium with carrier Zn and by applying activity with carrier Zn before equilibrium was set, there was no agreement in Zn_E in two methods. Increasing Zn_E with increasing Zn dose was observed by both methods only in alkaline typic ustochrept (4). In some soils higher E values than added amounts were observed, whereas, in soil 8 negative E values were obtained. The E values become erratic and are over estimated where complex reactions take place due to high pH, high O.C. and high complex forming elements.