Enhanced Erythrocyte Adhesiveness/Aggregation in Obesity Corresponds to Low‐Grade Inflammation

Objective: Previous studies have suggested that obesity enhances the inflammatory response, producing macromolecules involved in the induction and/or maintenance of increased erythrocyte aggregation. The objectives of this study were to evaluate the correlation between inflammation markers, erythrocyte adhesiveness/aggregation, and the degree of obesity and to assess phosphatidylserine expression on erythrocyte surface membrane of obese vs. nonobese individuals. Research Methods and Procedures: Erythrocyte adhesiveness/aggregation in the peripheral venous blood was evaluated by using a new biomarker, phosphatidylserine expression was assessed by means of flow cytometry, and markers of inflammation were measured in 65 subjects: 30 obese [body mass index (BMI) = 41 ± 7.7 kg/m²] and 35 nonobese (BMI = 24 ± 2.7 kg/m²) individuals. Pearson correlations and Student's t test were performed. Results: A highly significant difference was noted in the degree of erythrocyte adhesiveness/aggregation and markers of inflammation between the study groups. BMI correlated with erythrocyte adhesiveness/aggregation (r = 0.42, p = 0.001), erythrocyte sedimentation rate (r = 0.42, p = 0.001), high‐sensitive C‐reactive protein (r = 0.55, p < 10^?4), fibrinogen (r = 0.37, p = 0.004), and white blood cell count (r = 0.45, p < 10^?4). The degree of erythrocyte adhesiveness/aggregation correlated with erythrocyte sedimentation rate (r = 0.5, p < 10^?4), high‐sensitive C‐reactive protein (r = 0.56, p < 10^?4), fibrinogen (r = 0.54, p < 10^?4), and white blood cell count (r = 0.32, p = 0.01). Discussion: Our results suggest that obesity‐related erythrocyte adhesiveness/aggregation is probably mediated through increased concentrations of adhesive macromolecules in the circulation and not necessarily through hyperlipidemia or phosphatidylserine exposure on erythrocyte's membrane.     

The role of sulfhydryl groups in human neutrophil adhesion, movement and particle ingestion

Recent studies have suggested that ectosulfhydryl groups may play a role in cell contact phenomena. We have studied the possible role of ecto- and endosulfhydryl groups in the morphology, adhesiveness, random and directed (chemotaxis) motility and phagocytosis of human polymorphonuclear neutrophils. The rapidly penetrating sulfhydryl binding reagents HgCl₂ and NEM inhibited adhesiveness, motility and phagocytosis when studied at > 0.1 mM in plasma or > 0.01 mM in buffer. The difference in inhibitory concentration was shown to be due to the difference in albumin content of the two media. D-cysteine prevented the effect of HgCl₂ and NEM on cell morphology, adhesiveness, motility and phagocytosis indicating that their effects were on cell sulfhydryl groups. PCMBS, a very slowly penetrating organic mercurial, had no effect on neutrophil morphology, adhesiveness, motility or phagocytosis. However, PCMBS inhibited platelet aggregation, assuring its potency. These studies indicate that ectosulfhydryl groups are either not present or not participants in the maintainence of structure and functions of human neutrophilic granulocytes.     

Effect of homocysteine, cysteine, and their derivatives on the platelet link of hemostasis system

The influence of homocysteine, homocysteine thiolactone, cysteine and their derivatives on activation and aggregation of human platelets was investigated using the model systems in vitro. It was established that homocysteine and cysteine increased platelet aggregation induced by ADP, epinephrine, or collagen. Their action began in a range of concentrations such as their physiological blood levels (10 microM) and was increasing with the rise of their concentrations. Cysteine increased ADP-induced platelet aggregation, hardly any affect on epinephrine-induced platelet aggregation and depressed collagen-induced platelet aggregation in the highest concentration (1000 microM). Their disulfides and thioethers did not influence platelet aggregation.     

Comparison of locomotion, chemotaxis and adhesiveness of rabbit neutrophils from blood and peritoneal exudates

We compared the spontaneous behaviour (motility, adhesiveness, locomotion) and the chemotactic responses of exudate and blood-borne neutrophils. Directional locomotion of exudate neutrophils in 2% HSA-Gey's towards exudate fluid was not significantly changed, the response to activated autologous plasma diminished, and that to f-Met-Leu-Phe (10(-9) M) increased in comparison with blood-borne cells. The spontaneous behaviour of exudate cells in 2% HSA-Gey's (no gradient) differed markedly from that of blood-borne cells. In tissue culture medium (2% HSA-Gey's) exudate cells showed heightened motility in suspension and greater adhesiveness to glass substrata. These differences were eliminated by culturing the cells in their physiological media (i.e. plasma or exudate fluid). In contrast to blood-borne cells, exudate neutrophils tended to aggregate spontaneously. There was no correlation between neutrophil aggregation and adhesion to glass substrata of exudate cells in exudate fluid.     

中华菊头蝠的栖息生态特征及种群保护

中华菊头蝠(Rhinolophus sinicus)主要分布于我国境内,属于典型的洞栖食虫性蝙蝠,具有重要的研究意义与保护价值。近年,在湘西州境内的16个溶洞中对其栖息生态特征进行了观察,共记录到其个体12942只次,数据分析结果显示：该蝠是该区域溶洞中的居留型优势蝠种,具有集群冬眠的习性。每年的9月中下旬开始逐步聚群冬眠,翌年的3月底开始苏醒,其夏季的繁育场所非常隐蔽,通常位于人无法进入的洞段或人迹罕至的洞穴。总体上,其栖点主要集中于距洞口150—200 m(91.60%)的洞段,离地高度6—10 m(91.75%),多以“双足悬挂”的栖姿将身体悬空倒挂于洞道的顶壁。其体温与栖点温度之间不存在显著性差异(P>0.05),但具有明显的线性正相关关系(R~2=0.8886)。其栖点安全性春夏季高,秋冬季中等偏低。中华菊头蝠作为该区域洞栖性蝙蝠的优势种,在维持洞穴生态系统的稳定中发挥着至关重要的作用,加强对洞穴生态系统中蝙蝠伞护性的研究有助于洞穴生态保护教育及对蝙蝠种群的保护实践。     

Changes in cellular adhesiveness during the development of the slime mold Dictyostelium discoideum

A method was devised to measure the adhesiveness to the substratum of the amoebae of the cellular slime mold, Dictyostelium discoideum, and measurements were conducted with the cells at various stages of development. The adhesiveness of the vegetative amoebae was low, and remained unchanged as long as they fed on bacteria. During the transition from the vegetative stage to the interphase (due to the cessation of feeding), the adhesiveness increased rapidly, and afterwards continued to rise, as development proceeded. The adhesiveness of the interphase amoebae was greatly decreased by the treatment with proteolytic enzymes, lipase, and acid phosphatase. These indicate that accumulation of some substance(s) such as lipoprotein on the cell surface is responsible for the increase in adhesiveness during the interphase. EDTA and periodic acid had no noticeable effect on the adhesiveness of the interphase amoebae. EDTA, however, decreased the adhesiveness in co-operation with trypsin or lipase. The cells disaggregated from the anterior part of the migrating slug showed higher adhesiveness than those from the posterior part. The adhesiveness of either cells was higher than that of the interphase amoebae.     

A STUDY ON THE MECHANISM OF INTERCELLULAR ADHESION : Effects of Neuraminidase, Calcium, and Trypsin on the Aggregation of Suspended HeLa Cells

Aggregation of suspended HeLa cells is increased on removal of cell surface sialic acid. Calcium ions promote aggregation whereas magnesium ions have no effect. The calcium effect is abolished by previous treatment of the cells with neuraminidase. Trypsinization of the HeLa cells followed by thorough washing diminishes the rate of mutual cell aggregation. Subsequent incubation with neuraminidase restores the aggregation rate to the original value before trypsin treatment. Cells which had acquired a greater tendency for aggregation after removal of peripheral sialic acid lose this property when subsequently treated with trypsin. Calcium ions have no aggregative effect on trypsinized cells. In contrast to HeLa cells, aggregation of human erythrocytes was not increased after treatment with neuraminidase or on addition of calcium. The results with HeLa cells are interpreted as follows: (a) Trypsin-releasable material confers adhesiveness upon the cells. (b) The adhesive property of this material is counteracted by the presence of cell surface sialic acids. (c) Calcium ions exert their effect by attenuating the adverse effect of sialic acid.     

Comparative folliculogenesis and spermatogenesis of four teleost fish from a Reservoir in south‐eastern Brazil

Martins, Y.S., Moura, D.F., Santos, G.B., Rizzo, E. and Bazzoli, N. 2009. Comparative folliculogenesis and spermatogenesis of four teleost fish from a Reservoir in south‐eastern Brazil. —Acta Zoologica (Stockholm). 91 : 466–473. This study provides a comparative analysis of gametogenesis of neotropical teleosts Metynnis maculatus, Megalancistrus parananus, Cichla kelberi and Satanoperca pappaterra, through histological, histochemical and histometric techniques. In the ooplasm of C. kelberi and S. pappaterra conspicuous lipid vesicles were observed, which are characteristic of pelagic eggs produced by marine fishes. Perinucleolar oocytes were identified in the testis of S. pappaterra suggesting that this species is protogynous without functional hermaphroditism, an unusual pattern for neotropical fresh‐water fishes. The spermatozoa of the studied species have rounded heads, a characteristic of fish that externally fertilise their eggs. The follicular (granulosa) cells of the vitellogenic oocytes from the studied species were cuboidal or columnar, however, in C. kelberi there were columnar follicular cells at the vegetal pole and cuboidal cells at the animal pole. Variations of the histochemical content were detected in the cortical alveoli and follicular cells of vitellogenic oocytes showing differences in the mechanisms to block polyspermy and egg adhesiveness. Larger oocytes were recorded in species which demonstrated parental care behaviour and smaller oocytes were noted in those species with fractioned spawning.     

Normal platelet adhesiveness and aggregation in congenital PTA or Hageman factor deficiency

Platelet adhesiveness and aggregation were studied in two patients with congenital factor XI deficiency and in a patient with congenital factor XII deficiency. A normal aggregation pattern was observed in every instance, regardless of the aggregating agent. The same was true for platelet adhesiveness. It is concluded that factor XI and factor XII play no role in platelet aggregation and adhesiveness.     

Flagellar adhesion and deadhesion in chlamydomonas gametes: Effects of tunicamycin and observations on flagellar tip morphology

The aggregation-dependent loss of flagellar adhesiveness in Chlamydomonas reinhardi has been correlated with changes in flagellar tip morphology during adhesion and deadhesion. As aggregating mt^? and impotent (able to adhere, but not fuse) mt⁺ gametes begin to disaggregate in the presence of the protein synthesis inhibitor cycloheximide, there is a concomitant change in flagellar tip morphology from the activated bulbous form to the nonactivated tapered shape. The requirement of protein-synthetic activity for the maintenance of flagellar adhesiveness during aggregation may be due in part to turnover of proteins involved in formation or stabilization of activated flagellar tips. Incubation of aggregating gametes with tunicamycin indicates that, like protein synthesis inhibitors, this inhibitor of glycosylation also causes adhering gametes to deadhere. The results suggest that protein glycosylation may be essential for maintenance of adhesiveness during aggregation.     

Firebrats,Thermobia domestica,aggregate in response to the microbes Enterobacter cloacae and Mycotypha microspora

The firebrat, Thermobia domestica (Packard) (Thysanura: Lepismatidae), aggregates in response to the faeces of conspecifics as well as shelters previously inhabited by conspecifics. Our objective was to determine the source of the aggregation signal. Filter paper previously exposed to firebrats induced strong arrestment of firebrats. Polar solvents (water, methanol, acetonitrile) and less polar solvents (hexane, dichloromethane, ethyl ether), alone or in combination, failed to extract the aggregation signal from firebrat‐exposed paper. Moreover, solvent‐extracted paper continued to induce firebrat arrestment. In contrast, the aggregation signal could be obtained by physical extraction (freeze/thawing or ultrasonication) of firebrat‐exposed paper submerged in water. Five fungal species and four bacterial species were isolated from ultrasonicant solutions on potato dextrose‐, nutrient‐, and GlcNAc‐agar. Of the nine isolated microbes tested, only the fungus Mycotypha microspora Fenner (Mucorales) and the bacterium Enterobacter cloacae (Jordan) Hormaeche & Edwards (Enterobacteriaceae) induced arrestment of firebrats in bioassays. Our data support the conclusion that firebrats do not form aggregations in response to pheromones; instead, they aggregate in the presence of specific microbes or their metabolites.     

Behavioural responses of the vine weevil, Otiorhynchus sulcatus, to semiochemicals from conspecifics, Otiorhynchus salicicola, and host plants

The vine weevil Otiorhynchus sulcatus is a parthenogenetic reproducing species which forages for suitable host plants at night, but is found congregated in dark places during the day. Frass of this weevil species is suspected to contain attractive compounds that are host‐plant related. Using a still‐air olfactometer, we tested adult vine weevils at night for their behavioural response to odours from conspecifics, feeding on a mixture of spindle tree (Euonymus fortunei) and yew (Taxus baccata), and to a sexually reproducing related species (Otiorhynchus salicicola), feeding on a mixture of ivy (Hedera helix) and cherry laurel (Prunus laurocerasus). Their attraction to conspecifics and O. salicicola appeared to be related to frass production. Freshly collected frass from O. sulcatus and from O. salicicola males and females was attractive. Prunus laurocerasus and H. helix have not been observed to be hosts of the vine weevil in the field. However, our tests showed that the vine weevil was attracted to mechanically damaged leaves of both plant species, whereas undamaged leaves were not attractive. Only undamaged young unfolding leaves of H. helix were also attractive. The attraction to odours from mechanically damaged host and non‐host plants suggested the involvement of compounds that are commonly found in many plant species. The involvement of plant compounds and/or aggregation pheromones in attraction to frass of the vine weevil and frass of the related weevil species O. salicicola is discussed.     

The aggregation of questing ticks, Rhipicephalus pulchellus, on grass stems, with observations on R.appendiculatus

Rhipicephalus pulchellus was observed to aggregate on the tips of grass stems in the field in Kenya. Laboratory studies of this behaviour, using simulated glass ‘stems’ in sand-trays, showed that this aggregation was not due to responses to either (a) chemical marks placed on the stems by climbing ticks, or (b) other stimuli transmitted down the stems by ticks already at their tips. Instead, the aggregation on stems appeared to be an adventitious result of the ticks aggregating on the ground (in the lab., under filter paper covering the sand substrate of the apparatus) and then climbing the nearest stem in due course. Briefer, comparative observations on R. appendiculatus indicated that it was much more mobile on the stems, spending less time at their tips, and not obviously aggregating.     

Correlated expression of adhesive properties for both white and red blood cells during inflammation

The state of leukocyte and erythrocyte adhesiveness/aggregation was determined in the peripheral blood of 382 patients with infection/inflammation as well as in 72 controls by using a simple slide test and image analysis. A highly significant correlation (r = 0.4, n = 455, p < 0.001) was found between the state of leukocyte and erythrocyte adhesiveness/aggregation. The extent of both leukocyte and erythrocyte aggregation correlated with the concentration of fibrinogen. Significant aggregation of leukocytes with erythrocytes was noted as well. We conclude that both leukocyte and erythrocyte aggregation occur in the peripheral blood of patients with infection/inflammation. Such cell aggregation, which might have detrimental rheological consequences, can be detected by using our novel technique.     

Formation and maintenance of mating aggregations in a stink bug,Megacopta punctissimum (Montandon) (Heteroptera: Plataspidae)

Adults of a stink bug,Megacopta punctissimum, formed mating aggregations on their host plants: a few pairs in copula and a few bachelor males (males not in copula) stayed in the aggregation and the bachelor males waited for arriving females to mate with. The processes of formation and maintenance of the aggregations were observed using the individual marking technique. Aggregations initiated by 2 males or by 1 male and 1 female were usually joined by 1 or more individuals and lasted for several days, but aggregations initiated by 2 females broke up within 1 h. Aggregations were not maintained by the same members. The residence time (time from joining an aggregation to leaving the aggregation without copulating) of males was longer than that of females. There was a negative correlation between the residence time of males and the number of bachelor males in an aggregation when bugs joined it, while the residence time of females was positively correlated with the number of bachelor males in the aggregation. When bugs copulated after joining an aggregation, the postcopulatory residence time (time from completing copulation to leaving the aggregation) was longer in males than in females. Thus, males had a stronger tendency to initiate and maintain aggregations than females.     

Intercellular adhesion mediated by human muscle neural cell adhesion molecule: effects of alternative exon use

Mouse 3T3 fibroblasts were permanently transfected with cDNAs encoding isoforms of the neural cell adhesion molecule (N-CAM) present in human skeletal muscle and brain. Parental and transfected cells were then used in a range of adhesion assays. In the absence of external shear forces, transfection with cDNAs encoding either transmembrane or glycosylphosphatidylinositol (GPI)-linked N-CAM species significantly increased the intercellular adhesiveness of 3T3 cells in suspension. Transfection of a cDNA encoding a secreted N-CAM isoform was without effect on adhesion. Cells transfected with cDNAs containing or lacking the muscle-specific domain 1 sequence, a four-exon group spliced into the muscle but not the brain GPI-linked N-CAM species, were equally adhesive in the assays used. We also demonstrate that N-CAM-mediated intercellular adhesiveness is inhibited by 0.2 mg/ml heparin; but, at higher concentrations, reduced adhesion of parental cells was also seen. Coaggregation of fluorescently labeled and unlabeled cell populations was performed and measured by comparing their distribution within aggregates with distributions that assume nonspecific (random) aggregation. These studies demonstrate that random aggregation occurs between transfected cells expressing the transmembrane and GPI-linked N- CAM species and between parental cells and those expressing the secreted N-CAM isoform. Other combinations of these populations tested exhibited partial adhesive specificity, indicating homophilic binding between surface-bound N-CAM. Thus, the approach exploited here allows for a full analysis of the requirements, characteristics, and specificities of the adhesive behavior of individual N-CAM isoforms.     

Expression of v-src in embryonic neural retina alters cell adhesion, inhibits histogenesis, and prevents induction of glutamine synthetase.

Using Rous sarcoma virus as the vector, v-src or c-src genes were introduced into 6-day chicken embryo retina tissue in organ culture and their effects on retina development were investigated. Overexpression of c-src in many of the cells had no noticeable effect on retina development. In contrast, infection with v-src resulted in abnormal histogenesis and inhibition of differentiation. Although only a portion of the cells in infected tissue expressed the oncogene and displayed the transformation phenotype, the other cells were also hindered from becoming normally positioned and organized. Therefore, presence of oncogene-transformed cells within the tissue hindered organization and development of adjacent nontransformed cells. Failure of normal cell relationships impeded induction by cortisol of glutamine synthetase in Muller glia, which requires contact associations of the glia cells with neurons. The transformed cells tended to assemble into chaotic clusters, suggesting that their adhesiveness and contact affinities had become altered. This was confirmed by aggregation experiments with dissociated cells which showed that adhesiveness of transformed cells was greatly reduced and that they had lost the ability to cohere with nontransformed cells. In binary mixtures of transformed and nontransformed cells, the two sorted out into separate aggregates. Transformed cells formed loose clusters devoid of tissue architecture; aggregates of nontransformed cells became organized into retinotypic structures, and glutamine synthetase was inducible. Our findings suggest that the mechanisms of cell adhesion and cell affinities are a key target of v-src activity in infected cells and that modification of the cell surface may be a leading factor in other cellular changes characteristic of the v-src transformation phenotype.     

Field responses of the Asian larch bark beetle,Ips subelongatus,to potential aggregation pheromone components: disparity between two populations in northeastern China

Abstract Behavioral responses of the Asian larch bark beetle, Ips subelongatus Motsch. to three potential aggregation pheromone components, ipsenol (racemic or [?]‐enantiomer), ipsdienol (racemic or [+]‐enantiomer) and 3‐methyl‐3‐buten‐1‐ol, were tested using partial or full factorial experimental designs in two provinces (Inner Mongolia and Jilin) of northeastern China. Our field bioassays in Inner Mongolia (Larix principis‐rupprechtii Mayr. plantation) clearly showed that ipsenol, either racemic or 97%‐(?)‐enantiomer, was the only compound that significantly attracted both sexes of I. subelongatus, while all other compounds (singly or in combinations) were unattractive. There were no two‐ or three‐way synergistic interactions. However, in Jilin Province (L. gmelini[Rupr.] Rupr. Plantation), all the individual compounds tested were inactive, except a very weak activity by 97%‐(?)‐ipsenol in 2004 when the beetle population was very high. While a combination of ipsenol and ipsdienol (racemates or enantiomerically pure natural enantiomers) showed a significant attraction for both sexes of I. subelongatus, indicating a two‐way synergistic interaction between these two major components, addition of 3‐methyl‐3‐buten‐1‐ol to these active binary blend(s) did not have any effects on trap catches, suggesting that ipsenol and ipsdienol are the synergistic aggregation pheromone components of I. subelongatus in Jilin Province. It seems that 97%‐(?)‐ipsenol in Inner Mongolia or the binary blend of 97%‐(?)‐ipsenol and 97%‐(+)‐ipsdienol in Jilin Province are superior to their corresponding racemates, which might be due either to weak inhibitory effects of the antipode enantiomers or to reduced release rates of the active natural enantiomer(s) in the racemate(s). Our current bioassay results suggest that there is a strong geographical variation in aggregation pheromone response of I. subelongatus in northeastern China. Future research on the pheromone production and response of I. subelongatus from different regions in Northeast Asia will surely improve our understanding of the dynamic aggregation pheromone system of this economically important forest pest insect.     

Analysis of the Drosophila maternal effect mutant MAT(3)1 by pole cell transplantation experiments

Summary Pole cell transplantations were used to construct germ line mosaics of the Drosophila melanogaster maternal effect mutant mat(3)1. The mutant is of particular interest since the development of embryos derived from homozygous mat(3)1 females is arrested at the pole cell stage. Such embryos form exclusively pole cells and no blastoderm cells. By means of germ line mosaics we could demonstrate the primary target tissue of mutant gene expression. For normal development the mat(3)1 ⁺gene has to be expressed in the germ line. Pole cells formed in defective embryos derived from homozygous mutant mothers were transplanted into normal recipient embryos to test their developmental potential. Heterozygous mat(3)1 pole cells were found to form fertile gametes in both sexes whereas homozygous mat(3)1 pole cells form fertile gametes only in males. The lack of progeny derived from homozygous mat(3)1 donor pole cells in recipient females further demonstrates the germ line autonomy of the mat(3)1 mutation. Pole cells from defective embryos that are transplanted into normal hosts colonize the gonads with the same frequency as donor pole cells derived from normal embryos. This indicates that mat(3)1 derived pole cells are normal with respect to their function as germ cells and that the mat(3)1 mutant might therefore offer a convenient source for the mass isolation of functional pole cells.     

Design,Synthesis, and Evaluation of Chalcone Derivatives as Multifunctional Agents against Alzheimer's Disease

Fifteen chalcone derivatives 3a – 3o were synthesized, and evaluated as multifunctional agents against Alzheimer's disease. In vitro studies revealed that these compounds inhibited self-induced Aβ_1-42 aggregation effectively ranged from 45.9–94.5 % at 20 μM, and acted as potential antioxidants. Their structure-activity relationships were summarized. In particular, (2E)-3-[4-(dimethylamino)phenyl]-1-(pyridin-2-yl)prop-2-en-1-one ( 3g ) exhibited an excellent inhibitory activity of 94.5 % at 20 μM, and it could disassemble the self-induced Aβ_1-42 aggregation fibrils with ratio of 57.1 % at 20 μM concentration. In addition, compound 3g displayed good chelating ability for Cu²⁺, and could effectively inhibit and disaggregate Cu²⁺-induced Aβ aggregation. Moreover, compound 3g exerted low cytotoxicity, significantly reversed Aβ_1-42-induced SH-SY5Y cell damage. More importantly, compound 3g remarkably ameliorated scopolamine-induced memory impairment in mice. In summary, all the results revealed compound 3g was a potential multifunctional agent for AD therapy.