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Isolation and Properties of Floral Defensins from Ornamental Tobacco and Petunia1

Lay, Fung T.; Brugliera, Filippa; Anderson, Marilyn A.
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: text
Publicado em /03/2003 Português
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The flowers of the solanaceous plants ornamental tobacco (Nicotiana alata) and petunia (Petunia hybrida) produce high levels of defensins during the early stages of development. In contrast to the well-described seed defensins, these floral defensins are produced as precursors with C-terminal prodomains of 27 to 33 amino acids in addition to a typical secretion signal peptide and central defensin domain of 47 or 49 amino acids. Defensins isolated from N. alata and petunia flowers lack the C-terminal domain, suggesting that it is removed during or after transit through the secretory pathway. Immunogold electron microscopy has been used to demonstrate that the N. alata defensin is deposited in the vacuole. In addition to the eight canonical cysteine residues that define the plant defensin family, the two petunia defensins have an extra pair of cysteines that form a fifth disulfide bond and hence define a new subclass of this family of proteins. Expression of the N. alata defensin NaD1 is predominantly flower specific and is most active during the early stages of flower development. NaD1 transcripts accumulate in the outermost cell layers of petals, sepals, anthers, and styles, consistent with a role in protection of the reproductive organs against potential pathogens. The floral defensins inhibit the growth of Botrytis cinerea and Fusarium oxysporum in vitro...

Phosphatidylinositol-specific phospholipase C of Bacillus cereus: cloning, sequencing, and relationship to other phospholipases.

Kuppe, A; Evans, L M; McMillen, D A; Griffith, O H
Tipo: text
Publicado em /11/1989 Português
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The phosphatidylinositol (PI)-specific phospholipase C (PLC) of Bacillus cereus was cloned into Escherichia coli by using monoclonal antibody probes raised against the purified protein. The enzyme is specific for hydrolysis of the membrane lipid PI and PI-glycan-containing membrane anchors, which are important structural components of one class of membrane proteins. The protein expressed in E. coli comigrated with B. cereus PI-PLC in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, as detected by immunoblotting, and conferred PI-PLC activity on the host. This enzyme activity was inhibited by PI-PLC-specific monoclonal antibodies. The nucleotide sequence of the PI-PLC gene suggests that this secreted bacterial protein is synthesized as a larger precursor with a 31-amino-acid N-terminal extension to the mature enzyme of 298 amino acids. From analysis of coding and flanking sequences of the gene, we conclude that the PI-PLC gene does not reside next to the gene cluster of the other two secreted phospholipases C on the bacterial chromosome. The deduced amino acid sequence of the B. cereus PI-PLC contains a stretch of significant similarity to the glycosylphosphatidylinositol-specific PLC of Trypanosoma brucei. The conserved peptide is proposed to play a role in the function of these enzymes.

STUDIES OF ACUTE-PHASE PROTEIN. II. LOCALIZATION OF Cx-REACTIVE PROTEIN IN HEART IN INDUCED MYOCARDIAL INFARCTION IN RABBITS*

Kushner, Irving; Rakita, Louis; Kaplan, Melvin H.
Tipo: text
Publicado em /02/1963 Português
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Induced mouse spleen B-cell proliferation and secretion of immunoglobulin by lipid-associated membrane proteins of Mycoplasma fermentans incognitus and Mycoplasma penetrans.

Feng, S H; Lo, S C
Tipo: text
Publicado em /09/1994 Português
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Mycoplasmas have been implicated as a possible cofactor in AIDS pathogenesis. Mycoplasma fermentans and M. penetrans infect human immunodeficiency virus-positive patients at a significantly higher frequency than non-human immunodeficiency virus-infected control subjects. Various mycoplasmal membrane preparations are known to affect the functions of immune cells both in vitro and in vivo. A group of lipid-associated membrane proteins (LAMPs) extracted by Triton X-114 from mycoplasmas are major antigenic targets of human host antibody responses. In this study, LAMPs prepared from both M. fermentans and M. penetrans nonspecifically stimulated spleen cells of CBA/CaH mice to proliferate. LAMPs were also stimulatory to spleen cells from athymic mice. On the other hand, enriched splenic T cells from CBA/CaH mice with or without accessory cells responded poorly. Thus, the mitogenic effect of mycoplasmal LAMPs appeared mainly on B cells. High levels of immunoglobulin (Ig) M and low but detectable amounts of IgG were found in the supernatant of LAMP-treated splenic cell culture. M. penetrans LAMPs had a much more potent effect on murine spleen cells than did M. fermentans incognitus LAMPs in inducing both B-cell proliferation and Ig secretion. In conclusion...

INJURIES OF THE CRUCIAL LIGAMENTS OF THE KNEE-JOINT, WITH A NEW METHOD OF OPERATING FOR THE REPAIR OF THE POSTERIOR LIGAMENT

Tees, Frederick J.
Tipo: text
Publicado em /06/1932 Português
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Metal Complexation in Xylem Fluid 1: III. ELECTROPHORETIC EVIDENCE

White, Michael C.; Chaney, Rufus L.; Decker, A. Morris
Tipo: text
Publicado em /02/1981 Português
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The capacity of ligands in xylem fluid to form metal complexes was tested with a series of in vitro experiments using paper electrophoresis and radiographs. The xylem fluid was collected hourly for 8 hours from soybean (Glycine max L. Merr.) and tomato (Lycopersicon esculentum Mill.) plants grown in normal and Zn-phytotoxic nutrient solutions. Metal complexation was assayed by anodic or reduced cathodic movement of radionuclides (63Ni, 65Zn, 109Cd, 54Mn) that were presumed to have formed negatively charged complexes.

THE RELATION OF HIGH AND LOW UREA CLEARANCES TO THE INULIN AND CREATININE CLEARANCES IN CHILDREN WITH THE NEPHROTIC SYNDROME

Emerson, Kendall; Futcher, Palmer H.; Farr, Lee E.
Tipo: text
Publicado em /07/1941 Português
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Influence of glyceryl trinitrate during supine and upright exercise in patients with angina pectoris.

Thadani, U; Parker, J O
Tipo: text
Publicado em /11/1978 Português
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Hypoplastic right heart complex in a 46-year-old woman.

Horne, M K; Rowlands, D T
Tipo: text
Publicado em /01/1971 Português
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Abnormal haem biosynthesis in the chronic anaemia of rheumatoid arthritis.

Houston, T; Moore, M; Porter, D; Sturrock, R; Fitzsimons, E
Tipo: text
Publicado em /03/1994 Português
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OBJECTIVES--The chronic microcytic anaemia of rheumatoid arthritis (RA) occurs despite the presence of adequate reticulo-endothelial iron stores. The red cell microcytosis is evidence of impaired haemoglobin production. This study has examined possible abnormalities of erythroid haem biosynthesis that may contribute to the anaemia. METHODS--5-Aminolaevulinate (ALA) synthase and ferrochelatase activities were assayed in whole bone marrow and in purified erythroblasts from patients with RA and in control subjects. All patients were iron replete with demonstrable iron in the bone marrow. RESULTS--ALA synthase activity was significantly reduced in both whole bone marrow and purified erythroblasts from patients with the anaemia of RA. Erythrocyte protoporphyrin levels were raised in nine of 12 patients tested while ferrochelatase activity was normal. CONCLUSION--These abnormalities provide absolute evidence of abnormal erythroblast haem biosynthesis and iron metabolism in the anaemia of RA and most likely reflect decreased ALA synthase mRNA translation and some abnormality of erythroblast iron transport. Further studies using highly purified erythroblast populations will attempt to identify the causal factors leading to this abnormal erythroblast metabolism.

Evolving residency requirements for ambulatory care training for five medical specialties, 1961 to 1989.

Zones, J S; Schroeder, S A
Tipo: text
Publicado em /12/1989 Português
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Recent changes in the patient population of teaching hospitals, spurred by technologic advances and economic forces, have jeopardized the traditional hospital-based model of residency training. In consequence, there has been increasing attention paid to the need for ambulatory care experience. A primary force in shaping the content of postgraduate medical education is "The Essentials of Accredited Residencies," published in the Directory of Graduate Medical Education Programs. We reviewed recommendations and requirements for ambulatory settings and outpatient experience as specified in the Directory during the years 1961 to 1988 and investigated pending changes in requirements for five major specialties: internal medicine, pediatrics, family practice, general surgery, and obstetrics and gynecology. Increases in the amount of time residents spend in ambulatory care training recently have been mandated in internal medicine and are under consideration in two other specialties, indicating probable major shifts in the locus of postgraduate medical training.

Effect of the Intensity and Duration of Light at Various Temperatures on the Germination of Oldenlandia corymbosa L. Seeds

Corbineau, Françoise; Côme, Daniel
Tipo: text
Publicado em /11/1982 Português
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At temperatures below 35 to 40°C, fairly intense continuous white light (13 watts per square meter) inhibits germination of Oldenlandia corymbosa L. seeds, and the lower the temperature, the greater the inhibition. However, such lighting may enable seeds to germinate later in the dark; their degree of germinability depends both on the duration of lighting and on the temperature during lighting and after transfer to the dark.

Reviews and Notices of Books

Cobb, Stanley
Tipo: text
Publicado em /08/1924 Português
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Deuterium Isotope Effects in the Photocycle Transitions of the Photoactive Yellow Protein

Hendriks, Johnny; van Stokkum, Ivo H. M.; Hellingwerf, Klaas J.
Fonte: Biophysical Society Publicador: Biophysical Society
Tipo: text
Publicado em /02/2003 Português
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The Photoactive Yellow Protein (PYP) from Halorhodospira halophila (formerly Ectothiorhodospira halophila) is increasingly used as a model system. As such, a thorough understanding of the photocycle of PYP is essential. In this study we have combined information from pOH- (or pH-) dependence and (kinetic) deuterium isotope effects to elaborate on existing photocycle models. For several characteristics of PYP we were able to make a distinction between pH- and pOH-dependence, a nontrivial distinction when comparing data from samples dissolved in H2O and D2O. It turns out that most characteristics of PYP are pOH-dependent. We confirmed the existence of a pB′ intermediate in the pR to pB transition of the photocycle. In addition, we were able to show that the pR to pB′ transition is reversible, which explains the previously observed biexponential character of the pR-to-pB photocycle step. Also, the absorption spectrum of pB′ is slightly red-shifted with respect to pB. The recovery of the pG state is accompanied by an inverse kinetic deuterium isotope effect. Our interpretation of this is that before the chromophore can be isomerized, it is deprotonated by a hydroxide ion from solution. From this we propose a new photocycle intermediate...

The influence of micro-electrodes on neuronal discharge patterns in the auditory system

Stopp, Phyllis E.; Whitfield, I. C.
Tipo: text
Publicado em /06/1963 Português
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Assignment of the locus for congenital lactase deficiency to 2q21, in the vicinity of but separate from the lactase-phlorizin hydrolase gene.

Järvelä, I; Enattah, N S; Kokkonen, J; Varilo, T; Savilahti, E; Peltonen, L
Tipo: text
Publicado em /10/1998 Português
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Congenital lactase deficiency (CLD) is an autosomal recessive, gastrointestinal disorder characterized by watery diarrhea starting during the first 1-10 d of life, in infants fed lactose-containing milks. Since 1966, 42 patients have been diagnosed in Finland. CLD is the most severe form of lactase deficiency, with an almost total lack of lactase-phlorizin hydrolase (LPH) activity on jejunal biopsy. In adult-type hypolactasia, the most common genetic enzyme deficiency in humans, this enzyme activity is reduced to 5%-10%. Although the activity of intestinal LPH has been found to be greatly reduced in both forms, the molecular pathogenesis of lactase deficiencies is unknown. On the basis of the initial candidate-gene approach, we assigned the CLD locus to an 8-cM interval on chromosome 2q21 in 19 Finnish families. At the closest marker locus, a specific allele 2 was present in 92% of disease alleles. On the basis of a genealogical study, the CLD mutation was found to be enriched in sparsely populated eastern and northern Finland, because of a founder effect. The results of both the genealogical study and the haplotype analysis indicate that one major mutation in a novel gene causes CLD in the Finnish population. Consequently, the critical region could be restricted further...

Hypertrophic Pyloric Stenosis in Adult Patients: A Plea for a Simple Method of Operative Correction*

Feraru, Felix; Rosemond, George P.; Irons, H. Stuart; Zaino, Lawrence J.
Tipo: text
Publicado em /11/1961 Português
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Manual of Critical Care

Weigelt, John A.
Tipo: text
Publicado em /12/1987 Português
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Improvement in social-interpersonal functioning after cognitive therapy for recurrent depression

VITTENGL, J. R.; CLARK, L. A.; JARRETT, R. B.
Tipo: text
Publicado em /05/2004 Português
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Background. Cognitive therapy reduces depressive symptoms of major depressive disorder, but little is known about concomitant reduction in social-interpersonal dysfunction.

Cancer of the Fundus Uteri

Tipo: text
Publicado em /10/1936 Português
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