Chromosome 11q localization of one of the three expected genes for the human alpha-3-fucosyltransferases, by somatic hybridization.

Seventy-one human x mouse hybrid cell lines were used to map the locus of a human alpha-3-fucosyltransferase to 11q. The enzyme transfers fucose onto H type 2 more efficiently than onto sialyl-N-acetyllactosamine, suggesting that it is the myeloid type of alpha-3-fucosyltransferase (Mollicone et al., 1990), which makes the 3-fucosyllactosamine epitope on polymorphonuclear cells and monocytes. This epitope is also known as CD15 (Tetteroo et al., 1987).     

Ornithologische Notizen aus dem Ebrodelta

Zusammenfassung Im Ebrodelta ist, abgesehen von einigen Seen und Sümpfen, nur noch ein schmaler Küstenstreifen landwirtschaftlich ungenutzt. Hier hat sich ein Teil ursprünglichen Vogelreichtums erhalten, und hier wurde seit einigen Jahren eine Reihe faunistischer Erhebungen durchgeführt.Diese erbrachten mehrere erste Brutnachweise für Spanien oder die spanische Mittelmeerküste:Larus ridibundus, Sterna dougallii, St. sandvicensis, Haematopus ostralegus, Limosa limosa, Asio flammeus, Acrocephalus palustris. Als Rast- und Überwinterungsgebiet ist das Delta von großer Bedeutung, z. B. fürEgretta garzetta undPhoenicopterus ruber. Enge Beziehungen zur Camargue sind vielfach erkennbar, vielleicht sogar hinsichtlich der Ausbreitung vonLarus ridibundus undHaematopus ostralegus. Regelmäßige Wintervorkommen vonMarmaronetta angustirostris sind erwähnenswert.Es wird mit einigen bisher unbekannten Brutplätzen von Laro-Limicolen bekanntgemacht, von denen eine Kolonie vonSterna albifrons mit 300–400 Paaren besonders vermerkt sei. Für weitere Arten können Bestandsangaben gemacht werden.Dieses einzige, bedeutende Brut- und Rastgebiet zwischen Camargue und Coto Doñana ist in höchster Gefahr, durch intensivere landwirtschaftliche Nutzung und touristische Erschließung vernichtet zu werden.

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Resumen Datos ornitologicos sobre el Delta del Ebro. — Sin contar con charcas y marismas, el Delta del Ebro es una franja costera aun no explotada por la agricultura. Gracias a esto una numerosa variedad de aves ha podido mantenerse aprovechando las todavia persistentes condiciones orginarias del medio ambiente. Sobre estas aves se han venido acumulando en los ultimos años un buen acopio de observaciones.Se pudo constatar como nidificantes por primera vez en España o costas mediterranes a las siguientes especies:Larus ridibundus, Sterna dougalli, St. sandvicensis, Haematopus ostralegus, Limosa limosa, Asio flammeus, Acrocephalus palustris. Como lugar de invernada o refugio durante el paso el Delta del Ebro tiene un especial interes, por ejemplo paraEgretta garzetta yPhoenicopterus ruber. Se establecen algunas relaciones con la Camarga principalmente en cuanto a la expansión deLarus ridibundus yHaematopus ostralegus. Se mencionan invernadas regulares deMarmaronetta angustirostris. Se señalan algunos nuevos lugares de cria para Laro-Limicolas, merece destacarse el hallazgo de una colonia deSterna albifrons compuesta por unos 300–400 pares. Para otras especies se dan datos numerieos estimativos.El Delta del Ebro es un lugar unico y de gran importancia, situado entre la Camarga y el Coto de Doñana, que está hoy en peligro de desaparición debido a la colonización intensiva de la agricultura y a la creciente afluencia turistica.

     

Rat liver mitochondria contain two immunologically distinct dihydrolipoamide dehydrogenases

We have raised antisera against dihydrolipoamide dehydrogenase. One antigen was isolated from purified bovine kidney pyruvate dehydrogenase complex (PDC). The other antigen was a commercial preparation of porcine heart dihydrolipoamide dehydrogenase (E3) which did not first involve purification of the alpha-keto acid dehydrogenase complex(es). Both antibody preparations cross-reacted with the E3 components of PDC, alpha-ketoglutarate dehydrogenase complex, and branched-chain keto acid dehydrogenase complex. This demonstrates the immunological identity of the E3 components. These sera totally precipitated E3 activity from the purified complexes, from purified preparations of E3, and from extracts of rat heart and kidney mitochondria. The two sera vary in their reaction with rat liver mitochondrial extracts: the anti PDC-E3 serum left residual E3 activity (approximately 50% of the original) that was precipitable by the anti-E3 anti-serum. This indicates that liver contains two immunologically distinct forms of E3. Metabolic assays measuring the differential effects of the two sera on the glycine decarboxylation reaction suggest that the form which is immunologically nonreactive with the anti-PDC-E3 serum could represent the E3 involved in the glycine cleavage system.     

Trivalent behavior during prophase I in male mice heterozygous for three Robertsonian translocations: an electron-microscopic study

A synaptonemal complex (SC) analysis was carried out in male mice heterozygous (CHT/+) for three Robertsonian translocations. All pachytene preparations studied showed the presence of three trivalents. At early pachytene, the nonhomologous centromeric regions of the acrocentric chromosomes were unpaired. Heterosynapsis subsequently took place with complete pairing of the trivalents. Association between one of the three trivalents and the sex vesicle was observed in 30.4% of the nuclei. Association between the unpaired regions of two trivalents was present in 14.4% of the cells, suggesting that the relationship between unpaired regions of structural rearrangements and the X-Y bivalent may simply reflect the tendency of unpaired regions to establish end-to-end associations or heterosynapses among them, which are usually resolved during the pachytene stage of prophase I. Since the sex bivalent always has unpaired regions, these associations often affect the sex chromosomes.     

Standardized method for evaluation of hand disinfection by surgical scrub formulations

A standardized protocol for the evaluation of hand disinfection by surgical scrub formulations was applied to volunteers in a multicenter trial. Povidone iodine (PVI), chlorhexidine (CHX), and a nonmedicated soap (NMS) were tested. The scrubbing procedure involved three daily hand washings for five consecutive days; surviving bacteria were counted daily after being collected in a suitable neutralizing solution. Immediate efficacy (IE), cumulative efficacy (CE), and remanent effect (RE) were calculated by reference to the control hand. Statistical analyses of IE, CE, and RE showed significant differences among the three scrub formulations. IEs of PVI and CHX were equivalent and different from IE of NMS; CE and RE of CHX were higher than those of PVI and NMS. On the basis of the statistical analysis, the population size required for further studies aimed at detecting significant differences between surgical scrub formulations could be estimated.     

Antigenic probes locate binding sites for the glycolytic enzymes glyceraldehyde-3-phosphate dehydrogenase, aldolase and phosphofructokinase on the actin monomer in microfilaments.

The topology of the interfaces between actin monomers in microfilaments and three glycolytic enzymes (glyceraldehyde-3-phosphate dehydrogenase, aldolase and phosphofructokinase) was investigated using several specific antibodies directed against precisely located sequences in actin. A major contact area for glyceraldehyde-3-phosphate dehydrogenase was characterized in a region near residue 103. This interaction altered, by long-range conformational changes, the reactivity of antigenic epitopes in the C-terminal part of actin. The interface between actin and aldolase appeared to involve a sequence around residue 299 in the C-terminal region of actin. The interaction of phosphofructokinase, in contrast, modified the reactivity of all antibodies tested. Finally, the phosphagen kinases arginine kinase and creatine kinase showed no interaction with the microfilament.     

Appearance of B and H blood group antigens in the developing cochlear hair cells

Summary The presence of human blood-group antigens was analyzed in the rat cochlea during its postnatal development, using anti-A, anti-B and anti-H antibodies. At no stage was reactivity with anti-A antibody observed. With the anti-H antibody, a strong reactivity was observed from 1 to 9 days after birth within hair cells and some other surface epithelial cells of the cochlear duct. After postnatal day 9, only a faint reactivity persisted in a few non-sensory cells. With the anti-B antibody, only hair cells were selectively labeled. At early stages (postnatal day 1 and 3), the reactivity was intense and observed both around the cell surface and within the supranuclear region of cytoplasm. Later on, the reactivity decreased; it was limited at postnatal day 9 to a reactive spot below the cuticular plate. Results are compared with a preliminary finding describing the first appearance of B and H antigens in the organ of Corti at a prenatal stage, and with data concerning other sensory and neural structures. The appearance and progressive disappearance of B and H antigens on sensory and non-sensory cells can be correlated with significant events in the development of the cochlea. The transient expression of B and H antigens in cochlear sensory cells may correspond to developmental changes in their surface glycoconjugates.     

Light-temperature interactions on the growth of Antarctic diatoms

Summary The combined effect of various temperatures and light intensities on the growth of seven species of antarctic diatoms in culture has been studied. With the exception of Chaetoceros deflandrei whose thermal tolerance is fairly good, these obligatory psychrophils cannot survive in temperatures above 6° to 9° C. Their mean growth rate is relatively low, between 0.24 div d^–1 for Corethron criophilum and 0.63 div d^–1 for C. deflandrei. Regardless of light intensity, growth rate increased with the temperature to reach a maximum between 3° and 5° C. The highest rates were obtained between 115 and 220 mol m^–2 s^–1 with 0.38 div d^–1 for C. criophilum, 0.56 div d^–1 for Synedra sp. and between 0.71 and 0.88 div d^–1 for the other 5 species. A reduction in light intensity from 220 to 46 mol m^–2 s^–1 slowed growth by nearly 50%. These results suggest that the combined effect of temperature and light is one of the factors involved in the limitation of antarctic phytoplankton growth. The low temperatures of the environment do not permit rapid growth, which, even under optimal light conditions remains low. In addition, in the euphotic layer, the overall light energy available for algae is considerably reduced due to turbulence, a factor which exacerbates the reduced growth rate.     

A new cellular model of response to estrogens: a bioluminescent test to characterize (anti) estrogen molecules

With the aim of quickly and easily characterizing new estrogen or anti-estrogen molecules, we developed a cellular model in which estrogenic action can be detected by bioluminescence. This model is based on MCF-7 cells stably transfected with a receptor gene which allows expression of the firefly luciferase enzyme under control of the estrogen regulatory element of the Xenopus vitellogenin A2 gene. A stably transfected cell line (cultured for more than eight months without loss of the chimeric estrogenic response) was established by cotransfection of a neomycin resistance gene and cloning under selective pressure. Subcloning luminescent clones was accomplished by using a single-photon detecting camera. This cellular model allowed the study of an estrogenic activity either in whole-cell or in cell-free experiments by detection of the induced luciferase. Estradiol induced the luciferase activity in a dose-dependent manner at subnanomolar concentrations. The induced luciferase activity reached a maximum level as early as 24 hours after the cells were incubated with estradiol. The antiestrogen 4-hydroxy-tamoxifen inhibited the luciferase activity induced by estradiol. The cross-reactivity of ligands, such as dexamethasone, progesterone, testosterone, aldosterone, calcitriol, oxysterol and retinoic acid, were also studied, showing an estradiol specificity for a 24-hour incubation time.     

A model of antiglucocorticoid action for designing a potent glucocorticoid antagonist

We have previously shown that the biological efficacy of an antiglucocorticoid is directly related to its affinity for the glucocorticoid receptor in whole cells at 37 degrees C. We have also shown that RU 486-receptor complexes differ from other antiglucocorticoid-receptor complexes in so far as their affinity is as high at 37 degrees C in whole cells as at 0 degree C in a cell-free system, whereas a decrease by a factor of 5-10 is observed with the other antagonists. The aim of the present paper was to evaluate the contributions of temperature and cellular integrity (or the biological events linked to temperature and cellular integrity) to the affinity of a steroid for its receptor for the purpose of determining the parameters favorable to high affinity, which is the prerequisite of a potent antagonist. We provide evidence showing that: (1) an increase in temperature has an unfavorable effect on the affinity of a glucocorticoid for its receptor (4-6-fold decrease between 0 and 37 degrees C), (2) RU 486, like an agonist, forms a complex with the cytosolic glucocorticoid receptor, which satisfies the criteria for an "activated" complex under "in vitro activating treatment", (3) these biological post-binding events (either agonistic or otherwise nature), which change the nature of the complexes, contribute to compensating for the negative effect of rising temperatures on their apparent dissociation constant. We conclude that potent antiglucocorticoids must have a chemical structure allowing them to induce biological post-binding events, such as receptor activation, but in an abortive form which thus effectively "traps" the receptor in a non-functional state.