The Alzheimer amyloid precursor-related transcript lacking the beta/A4 sequence is specifically increased in Alzheimer's disease brain

The deposition of cerebrovascular and plaque amyloid in the CNS is a primary feature of Alzheimer's disease and aged Down's syndrome pathology. The localization of the Alzheimer amyloid protein precursor (APP) gene on chromosome 21, along with its overexpression in Down's syndrome brain compared with normal brain, suggests that alterations in APP gene expression may play a role in the development of the neuropathology common to the two diseases. In the present report, we demonstrate that a specific spliced form of mRNA that is transcribed from the APP gene and that lacks the beta/A4 sequence is elevated in the nucleus basalis, occipitotemporal cortex, and parahippocampal gyrus in Alzheimer's disease brain relative to controls. These results are based on combined data from RNA slot blot analysis, in situ hybridization, and polymerase chain reaction quantification of specific mRNAs taken directly from tissue sections.     

A positional marker for the dorsal embryonic retina is homologous to the high-affinity laminin receptor

In a search for determinants of positional information in the embryonic eye, we isolated two monoclonal antibodies that label strongly the dorsal part of the undifferentiated embryonic retina in mammals, bird and cold-blooded vertebrates. In the chick, the optic tectum is labeled in a corresponding fashion, the ventral tectum more heavily than the dorsal tectum. Through biochemical and molecular analysis both antibodies were found to recognize a protein that has been cloned repeatedly, first in a screen with antibodies to the '68K-laminin receptor' (Wewer et al. (1986) Cancer Res. 47, 5691-5698), a name that may not exhaustively describe its function. Western blots show the protein to be present in most or all tissues, and Western and Southern blots reveal a high degree of conservation in the detected signals up to invertebrates and bacteria. Despite the very strong and selective labeling of the dorsal retina in conventional immunohistochemical preparations, the protein and its mRNA are present in even amounts throughout the embryonic retina, as demonstrated by Western and Northern blots of bisected retinas, and immunohistochemically in retinas fixed with ethylene glycole bissuccinimide (EGS), an NH2-group crosslinker with very long spacer arm. This indicates that the dorsoventral asymmetry in the embryonic retina is not in the amount but in the configuration of this protein; whether this difference relates to laminin binding is not known.     

Bacteriophage receptors of Lactococcus lactis subsp. 'diacetylactis' F7/2 and Lactococcus lactis subsp. cremoris Wg2-1

Bacteriophage P008 revealed irreversible and uniform adsorption to cell walls of L. lactis subsp. 'diacetylactis' F7/2, whereas phage P127 adsorbed reversibly to a limited number of receptor sites on cell walls of L. lactis subsp. cremoris Wg2-1. Neither extraction of lipids, cell wall- and membrane-teichoic acids nor enzymatic degradation of proteins altered the binding efficiencies of both cell wall fractions. However, phage binding was inhibited, when cell walls were subjected to lysozyme, metaperiodate, or acid treatments. This reflects that a carbohydrate component embedded in the peptidoglycan matrix is part of the phage receptors of strains F7/2 and Wg2-1.     

Plasma and liver selenium levels in the rat during supplementation with 0.5, 2, 6, and 15 ppm selenium in drinking water

Plasma and liver selenium of Wistar rats were determined after 1, 3, and 6 mo supplementation with 0.5, 2, 6, or 15 ppm selenium as sodium selenite in drinking water. Plasma selenium was not different from control values at additional intake of 0.5 ppm but increased above usual levels at higher intakes. A highly significant correlation was observed between the total quantity of selenium ingested and plasma selenium after 1 mo treatment (r=0.99,p<0.01), but was less pronounced after 3 and 6 mo (0.94,p<0.05, and 0.78,p<0.05, respectively). The decrease in plasma selenium with time of treatment was more pronounced at higher intakes. There was also a highly significant correlation between total selenium intake and liver selenium concentration (r=0.99,p<0.01) after 1 mo of treatment, but this time liver selenium did not change with time, and the correlation remained highly significant throughout the investigation. Liver selenium therefore appears as a more sensitive and more representative measure of selenium intake than plasma selenium. Most supplements did not affect body weight and survival of animals, except when the diet was supplemented with 15 ppm for 6 mo; however, alterations in biochemical parameters concerning lipid status and hepatic function were observed at levels above 2.0 ppm.     

Molecular cloning and expression of the rat beta 1-adrenergic receptor gene.

Using the sequence homology approach for cloning related genes within the G-protein-coupled receptor gene family, we have cloned the gene for the rat beta 1-adrenergic receptor (beta 1-AR). The rat beta 1-adrenergic receptor gene was isolated from a lambda EMBL3 rat genomic DNA library using the hamster beta 2-adrenergic receptor (beta 2-AR) coding sequence as a probe under low stringency hybridization conditions. The rat beta 1-AR gene encodes a protein of 466 amino acids that contains one consensus site for N-linked glycosylation (Asn-15) and three consensus sites for cAMP-dependent protein kinase phosphorylation (Ser-296, Ser-301, and Ser-401). The encoded rat beta 1-AR is 98 and 91% similar at the amino acid level with the human beta 1-AR in the transmembrane domains and in the overall sequence, respectively. Genomic Southern blot and gene dosage analyses indicate that the rat beta 1-AR gene is a single copy gene. The tissue distribution of the rat beta 1-AR mRNA was highest in the pineal gland with other brain regions and peripheral tissues, including the heart, expressing the mRNA at moderate levels. The bacteriophage clone containing the rat beta 1-AR gene with its natural promoter was co-transfected with the selectable marker (pRSVneo) conferring neomycin resistance into beta 1-AR-deficient mouse L cells. Analyses of the selected transfectant demonstrates efficient expression of the beta 1-AR gene and functional receptor. 125I-Labeled iodocyanopindolol bound transfectant membranes with an affinity of KD = 24 pm; the beta 1-AR-selective antagonist ICI 89,406 displaced iodocyanopindolol binding with a Ki approximately 140 times lower than that for the beta 2-AR-selective antagonist ICI 118,551. In addition, in the transfectant cell line, adenylylcyclase was stimulated by beta-adrenergic receptor agonists with the rank order of potency of isoproterenol greater than norepinephrine = epinephrine, consistent with properties expected of the beta 1-AR subtype.     

Paperwork,patronage, and citizenship: the materiality of everyday interactions with bureaucracy in Tamil Nadu,India

This article explores the material practices through which lower-caste and poor villagers engage with bureaucracy in contemporary India. We take documents and paperwork – such as ration cards and community certificates – as a ‘lens’ through which to explore how paper materiality is infused with the politics of power, patronage, and identity. The article brings ethnography from rural Tamil Nadu, South India, in conversation with two bodies of literature: one on the materiality of bureaucracy and one on the nature of political mediation in contemporary India. We demonstrate how everyday engagements with paperwork as well as processes of applying, form filling, and securing recommendations are constitutive of social and political relationships and, ultimately, of citizenship itself. Political mediation around paperwork and bureaucracy generates a hierarchy of citizens rather than equal citizenship for all, yet ordinary villagers transpire as anything but passive. Drawing on patronage networks, engaging in affective performances, and navigating a politics of identity, they actively negotiate access to the state in an attempt to claim their rights as citizens.     

Cyclic lipopeptide-producing Pseudomonas koreensis group strains dominate the cocoyam rhizosphere of a Pythium root rot suppressive soil contrasting with P. putida prominence in conducive soils

Pseudomonas isolates from tropical environments have been underexplored and may form an untapped reservoir of interesting secondary metabolites. In this study, we compared Pseudomonas and cyclic lipopeptide (CLP) diversity in the rhizosphere of a cocoyam root rot disease (CRRD) suppressive soil in Boteva, Cameroon with those from four conducive soils in Cameroon and Nigeria. Compared with other soils, Boteva andosols were characterized by high silt, organic matter, nitrogen and calcium. Besides, the cocoyam rhizosphere at Boteva was characterized by strains belonging mainly to the P. koreensis and P. putida (sub)groups, with representations in the P. fluorescens, P. chlororaphis, P. jessenii and P. asplenii (sub)groups. In contrast, P. putida isolates were prominent in conducive soils. Regarding CLP diversity, Boteva was characterized by strains producing 11 different CLP types with cocoyamide A producers, belonging to the P. koreensis group, being the most abundant. However, putisolvin III-V producers were the most dominant in the rhizosphere of conducive soils in both Cameroon and Nigeria. Furthermore, we elucidated the chemical structure of putisolvin derivatives—putisolvin III-V, and described its biosynthetic gene cluster. We show that high Pseudomonas and metabolic diversity may be driven by microbial competition, which likely contributes to soil suppressiveness to CRRD.