The integration of negative affect, pain and cognitive control in the cingulate cortex

It has been argued that emotion, pain and cognitive control are functionally segregated in distinct subdivisions of the cingulate cortex. However, recent observations encourage a fundamentally different view. Imaging studies demonstrate that negative affect, pain and cognitive control activate an overlapping region of the dorsal cingulate--the anterior midcingulate cortex (aMCC). Anatomical studies reveal that the aMCC constitutes a hub where information about reinforcers can be linked to motor centres responsible for expressing affect and executing goal-directed behaviour. Computational modelling and other kinds of evidence suggest that this intimacy reflects control processes that are common to all three domains. These observations compel a reconsideration of the dorsal cingulate's contribution to negative affect and pain.     

Influence of secretory immunoglobulin A and purified secretory component on dextran-sucrase activity of Streptococcus mutans.

The net stimulation of dextransucrase EC 2.4.1.5) activity from Streptococcus mutans HS6 by dextran, secretory immunoglobulin A, or secretory component was investigated. Approximately equal stimulation resulted from treatment with these three components.     

Effect of a disulfide-interchange enzyme on the assembly of human secretory immunoglobulin A from immunoglobulin A and free secretory component.

A disulfide-interchange enzyme from rat liver microsomes was found to promote binding in vitro of human free secretory component (SC) to dimeric serum-type IgA containing J chain, as assessed by immune precipitation and gel filtration. This effect was greater withe native than with partially reduced SC. Most of the bound SC was covalently linked, as determined by electrophoresis in polyacrylamide gels in detergent. The enzyme did not promote binding of native or partially reduce SC to IgG, IgA monomer, IgA dimer without J chain, or IgM. In the case of IgM, the enzyme did, however, promote covalent bonding of previously non-covalently linked SC. The results overall suggest that a disulfide-interchange enzyme could play a role in vivo in the cell-associated assembly of secretory IgA by promoting the covalent attachment of SC to a dimer of serum-type IgA and that the J chain in the IgA dimer contributes to the enzyme effect.     

Influence of nucleic acids and polysaccharides on phosphotransferase activity of preparations of secretory immunoglobulin A from human milk

The influence of nucleic acids (DNA, tRNA), synthetic oligonucleotides, and polysaccharides (lipopolysaccharides from Escherichia coli, heparin) on protein kinase and lipid kinase activities of preparations of human secretory immunoglobulin A (sIgA) has been studied. The preparations of sIgA were isolated from human milk by chromatography on the column with Protein A-Sepharose and DEAE-sorbent (sIgA1), by affinity chromatography of sIgA1 on DNA-cellulose (sIgA2), and by gel-filtration of sIgA1 in buffer containing 5% dioxane (sIgA3). Two 32P-labeled products with high and low electrophoretic mobility in polyacrylamide gel containing SDS were found after incubation of sIgA1 and sIgA2 with [gamma-32P]ATP. The product with low electrophoretic mobility was degraded in 10% trichloroacetic acid giving a radioactive background in lanes of the polyacrylamide gel. 32P-Labeled phospholipids were found among the phosphorylation products. Soluble and immobilized DNA increase lipid kinase activity of preparations of sIgA. In this case the secretory component and H-chains of sIgA were degraded. Fractions possessing lipid kinase activity were precipitated in the presence of heparin (1 mg/ml), and lipid kinase activity was separated from sIgA by gel-filtration in buffer containing 5% dioxane. 32P-Labeled products were formed in the presence of [gamma-32P]ATP as well as [32P]ortho-phosphoric acid. The influence of heparin and synthetic deoxy- and ribooligonucleotides on casein kinase activity of sIgA3 was studied. It was observed that deoxyribooligonucleotides in micromolar concentrations increased the rate of casein phosphorylation in the presence of sIgA3 and [gamma-32P]ATP. It has been proposed that catalytically active sIgA have an affinity to DNA (anti-DNA sIgA) and can be present in human milk as a part of lipoprotein complexes.     

FcalphaRI-positive liver Kupffer cells: reappraisal of the function of immunoglobulin A in immunity

Despite the well-recognized involvement of immunoglobulin (Ig) A in mucosal immunity, the function of its receptor, FcalphaRI (CD89), is poorly understood. The ability of FcalphaRI to activate leukocytes seems to conflict with the proposed anti-inflammatory activity of secretory IgA. We show here that in a transgenic mouse model, inflammatory mediators induced expression of FcalphaRI on Kupffer cells, which enabled efficient phagocytosis in vivo of bacteria coated with serum IgA. Secretory IgA did not initiate phagocytosis. Therefore, interactions between serum IgA and FcalphaRI on Kupffer cells may provide a 'second line of defense' in mucosal immunity, by eliminating invasive bacteria entering through the portal circulation and thus preventing disease.     

The serosa of Manduca sexta (Insecta, Lepidoptera): ontogeny, secretory activity, structural changes, and functional considerations

In Manduca sexta, the blastoderm forms successively and becomes immediately cellularized as the cleavage energids reach the surface of the oocyte. Presumptive serosal cells are large and contain 2 or 4 large polyploid nuclei; presumptive embryonic cells are small and mononuclear. All parts of the blastoderm participate in the uptake and digestion of yolk material. About 10 h post-oviposition, the blastoderm breaks at the amnioserosal fold and the extraembryonic part closes above the germ band and constitutes the serosa (12 h post-oviposition, i.e. 10% development completed). At once, the serosa starts to secrete a cuticle consisting of an epi- and a lamellated endocuticle. Detachment of the serosal cuticle, 22h post-oviposition, is reminiscent of apolysis of larval cuticle. Thereafter, the serosa deposits a membranous structure, the serosal membrane. The sercretory process lasts from 23h to 44h post-oviposition. At first a fine granular layer, then an amorphous, spongy-like, fibrillar layer is secreted via microvilli. This persisting membrane is tough, rubbery and very elastic. It may serve to bolster the serosa during katatrepsis (48h post-oviposition) and later embryonic movements. After detachment of the serosal membrane, 44h post-oviposition, a distinct subcellular reorganization of the serosa takes place. The nuclei become still larger and more irregular. Uptake of yolk granules, but not of lipid droplets, ceases, although interaction of serosa and yolk cells are intense. Serosal cells include many mitochondria, large areas of rER, besides some sER, increasing amounts of lysosomal bodies and prominent Golgi complexes. Most conspicuous is the assembly of spindle-shaped, electron-lucent vesicles below the apical surface. These vesicles may contain metabolic products which are released into the peripheral space. The studies show that the serosa assumes changing functions during embryogenesis: digestion of yolk substances, synthesis of a serosal cuticle and a serosal membrane, which may have a protective function, and excretion.     

Continuity and prospects of research in systemic integrative psychophysiology of functional states and cognitive activity

An important problem of psychophysiology related to the study of the integration of the mechanisms controlling the state of the brain and characteristics of the cerebral organization of cognitive activity is discussed. The fundamental role of the results of long-term research in the neurophysiology of functional states as the basis of the organization of mental activity under conditions of direct, long-term, sparing contact with the cortex and subcortical structures by means of long-term intracerebral electrodes carried out by Academician Bechtereva and her scientific school is demonstrated. The commensurability and complementarity of slow and ultraslow gradual neurophysiological processes with similar amplitude-time parameters recorded in intravitally identified zones of deep cerebral structures and from scalp sites corresponding to the cortical projections of the main integrative centers are substantiated. The notion of the brain as a complexly organized, “floating,” multicircuit neurodynamic suprasystem with hierarchically, probabilistically organized vital processes varying in rate and intensity that are involved in maintaining the state of rest, mental states, and cognitive activity are formulated and substantiated. While the set of universal neurodynamic languages is limited, the brain employs a multiregister mechanism controlling the state and selective mechanisms of integration, ensuring the contribution of gradual neurophysiological processes at different levels of the structural and functional organization that vary in terms of information content in the formation of the cerebral systems underlying specific cognitive activities.     

Potato sucrose synthetase: purification, properties, and changes in activity associated with maturation

Sucrose synthetase activity is high in young potato tubers but decreases markedly during maturation. The activity decreases rapidly after the tubers are harvested and remains low regardless of storage temperature. This enzyme was purified 34-fold from freshly harvested immature potatoes. It catalyzes both cleavage and synthesis of sucrose but the 2 activities differ in a number of ways. The pH optima are 6.6 and 8.8 for sucrose cleavage and synthesis. respectively. Sucrose cleavage is activated 4-fold by mercaptoethanol and is inhibited by Mn²⁺. In contrast, sucrose synthesis is activated only slightly by either mercaptoethanol or Mn²⁺ alone but 2-fold in the presence of both reagents. However, it was not possible to resolve the 2 activities, their stabilities to partial thermal inactivation are identical, and their ratios are constant over a wide range of activities.     

Defensins,lectins, mucins,and secretory immunoglobulin A: microbe-binding biomolecules that contribute to mucosal immunity in the human gut

In the intestine, the mucosal immune system plays essential roles in maintaining homeostasis between the host and microorganisms, and protecting the host from pathogenic invaders. Epithelial cells produce and release a variety of biomolecules into the mucosa and lumen that contribute to immunity. In this review, we focus on a subset of these remarkable host-defense factors – enteric α-defensins, select lectins, mucins, and secretory immunoglobulin A – that have the capacity to bind microbes and thereby contribute to barrier function in the human gut. We provide an overview of the intestinal epithelium, describe specialized secretory cells named Paneth cells, and summarize our current understanding of the biophysical and functional properties of these select microbe-binding biomolecules. We intend for this compilation to complement prior reviews on intestinal host-defense factors, highlight recent advances in the field, and motivate investigations that further illuminate molecular mechanisms as well as the interplay between these molecules and microbes.     

The early changes of parietal cell structure in the course of secretory activity in the rat

The fine structure of the rat parietal cell was studied, both at rest and after stimulation by refeeding or insulin administration. Experiments on fixation procedures showed that whenever the fixative contained sucrose at a concentration higher than 0.2 M, the system of cytoplasmic membranes was clearly tubular in arrangement, whereas the omission of sucrose in the fixative usually resulted in a vesicular structure. The study with the high-voltage electron microscope of thick sections prepared by conventional techniques or by impregnation with zinc iodide-osmium (ZIO) revealed that the tubules are grouped into fascicles, and that these form a feltwork that is especially thick toward the cell apex. The development of the secretory canaliculus after stimulation appears to take place by an in situ remodeling of the cytoplasmic domain occupied by the tubular system. Cells examined after short periods of stimulation (5-15 min) showed images of the tubular system and of the canalicular structure which differed both from the nonstimulated and from the fully active (30-45 min of stimulation) cell. These features include the formation of wide cisternae and of pericanalicular cytoplasmic trabeculae or laminae, whose fine structure bears close resemblance to that of the intracanalicular processes in the same cells. These images can be ordered into a hypothetical sequence which is proposed as a model to explain the transformation of the tubular system and intervening cytoplasmic matrix into secretory canaliculus.     

Levels of secretory immunoglobulin A, lysozyme (muramidase) and albumin in healthy adults of different ages

The content of secretory IgA (sIgA,) lysozyme and albumin was studied in the saliva of 40 health-service employees of different ages without evident signs of disease. The levels of lysozyme decrease significantly with the advancing age whereas those of sIgA and albumin do not decrease up to the age of 55. The levels of lysozyme and sIgA show a significant mutual correlation.     

A comparison of the actions of trypsin and pepsin on porcine immunoglobulin M and their effects on biological activity

The action of trypsin at 55 degree C and pH 8.3 on pig IgM anti-Salmonella has been compared with the action of pepsin at 37 degree C and pH 4.6. Both processes cause the gradual removal of Fab arms and Cmu2 domains to produce eventually an (Fc)5 fragment. However, during tryptic digestion Fab arms are preferentially removed from the same subunit, whereas peptic digestion causes random removal from any subunit. At intermediate stages of digestion both processes produce partially fragmented molecules which consist of an (Fc)5 portion still attached to limited numbers of Fab arms. Both processes cause a gradual decrease in the ability of molecules to agglutinate Salmonella, but complement fixation by the complexes declines much more rapidly. A stage is reached where molecules having four Fab arms can still agglutinate but there is no complement fixation. However, the remaining arms on the tryptic molecules are distributed in pairs on the same subunit, whereas those on the peptic molecules are distributed randomly. Hence the number of remaining Fab arms, rather than their distribution, appears to be the critical factor which influences biological activity. A possible explanation for this is discussed.     

Multiple effects of phorbol ester on secretory activity in rabbit gastric glands and parietal cells

Acid secretory activity and respiration in rabbit gastric glands are stimulated by cAMP-dependent and -independent agonists. Potentiation between agonists suggests interaction of the activation pathways. Regulation of secretory response by protein kinase C was investigated with 12-0-tetradecanoyl phorbol-13-acetate (TPA). TPA elevated basal respiration, pepsin release, and acid secretion but inhibited histamine and carbachol stimulation of acid secretion by gastric glands, as measured by [dimethylamino-14C]aminopyrine accumulation. The inhibition of histamine response was specific for protein kinase C activators, occurred after a 20-min lag, and was not reversed by removal of TPA after 3 min of preincubation. TPA pretreatment inhibited acid secretory responses to cholera toxin and forskolin but enhanced the response to cAMP analogues. Cholera toxin and pertussis toxin simulated ADP-ribosylation of 45 and 41 kDa proteins, respectively, in parietal cell membranes. Therefore, both stimulatory (Gs) and inhibitory (Gi) GTP binding proteins of adenylyl cyclase appear to be present in parietal cells. Pretreatment with pertussis toxin attenuated PGE2 but not TPA inhibition of histamine stimulation of aminopyrine accumulation. Thus, the inhibitory effect of TPA does not appear to be associated with an action on Gi. The results with histamine and carbachol suggest that protein kinase C may regulate both cAMP-dependent and -independent stimulation of parietal cell acid secretion.     

Studies on secretory activity in the pars intermedia of Xenopus laevis 2: A biochemical and electron cytochemical investigation of acid hydrolase activity following the stimulation of secretory activity in vivo

In the MSH cell at the onset of secretory activity, acid hydrolase activity increases. This increased activity, shown quantitatively by assaying beta-glycerophosphatase and R-glucuronidase within the stimulated gland, has been shown by electron cytochemical methods for beta-glycerophosphatase (acid phosphatase) and aryl sulphatase to be related to the production of large numbers of dense bodies. Cytochemical evidence also supports the view that these lytic bodies arise from GERL-like cisternal elements since it is shown that in addition to the flattened, parallel Golgi cisternae these elements are also R-glycerophosphatase-positive. The similarities between the dense bodies and those of other cell types are described and discussed.     

Cell types of the pars distalis: seasonal changes in secretory activity and effect of steroids on spermatogenesis in Rana hexadactyla

Cytomorphological features and tinctorial affinities of the adenohypophyseal gonadotrophs have been studied in stained preparations of the pituitary of adult male frogs Rana hexadactyla Lesson, at monthly intervals during a calendar year. All the five morphologically distinct cell types showed a progressive increase in size from August of February, followed by a decrease from March to July. Extrusion of the synthetized product occurred in the summer and during this period production was low. Injection of steroids viz. stilboestrol, testosterone, oestradiol, doca and cortisol, interfered with the elaboration and secretion of gonadotropins, the adenohypophyseal feedback mechanism, and the sensitivity of the germinal epithelium. Changes in gonadotropins secretion and their impact on the testis are discussed.     

Perceived change in the affect associated with dreams: The fading affect bias and its moderators.

Eighty-two undergraduate participants kept dream diaries for a month. Five dreams were randomly selected from each diary and were returned to participants. They rated the affect produced by the dream at its occurrence and at its recall, as well as a number of other characteristics of the dream and characteristics of the context in which the dream occurred. Results revealed that, like memories for real autobiographical events, the negative affect associated with dreams generally faded faster than the positive affect associated with dreams (a Fading Affect Bias, or FAB). The data also showed that the FAB did not occur for: (a) dreams that were remembered to contain information that dreamers believed came true at a later date, (b) dreamers who had reportedly taken recreational drugs prior to their dream, (c) dreams remembered as lacking sound, and (d) dreams remembered as very quiet. (PsycINFO Database Record (c) 2010 APA, all rights reserved)