Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Plantae”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1977

[Expert-testimony and therapeutic findings and observations in wine-dressers of the Mosel-region with late sequelae of arsenic intoxication].

During the years 1972--1976 an overall number of 122 vine-dressers of the middle Moselle region called for examination, control, and medical treatment because of late damages caused by arsenic intoxication. In 1976 there were twenty-two new cases. By keratolytic treatment, excision, cauterization, and X-ray therapy a considerable reduction of precancerous and carcinous degenerations of the skin caused by arsenic in the form of keratosis and melanosis of the head, rump, arms, chest, volae and plantae could be achieved. By comparing two groups of vine-dressers with skin damages caused by arsenic a distinct reduction of praecancerous and carcinous degenerations of the predestined skin regions could be seen in those who had had medical treatment. A 3 months' dermatological survey of the patients is required.

Aged↗
PubMed1977

Do hormonal (stress) and vascular (ischaemia) factors contribute to reflex muscle atrophy induced by chronic nociceptive stimulation in rats?

1. Reflex muscle atrophy was induced in rats by fracturing the metatarsal bones of one hind paw and injecting 0.02 ml turpentine oil into the planta under shortlasting ether anaesthesia. The atrophy thus evoked in the soleus and extensor digitorum longus (EDL) was compared with the contralateral muscles. 2. There was a twelvefold increase of plasma corticosteroid levels one hour after application of the above nociceptive stimulus and the levels were still somewhat enhanced at 3 days. Neither bilateral adrenalectomy nor administration of corticosteroid hormones or cold stress affected the development of reflex atrophy. 3. Restriction of the arterial blood supply (ligature of the common iliac artery) led to a slowly progressing atrophy with a maximum 10 days after the ligature. Reflex atrophy introduced at different times after ligature was not enhanced. 4. These results are interpreted as evidence that neither general stress (and the effect of catabolic hormones) nor local restriction of muscle blood flow (by reflex vasospasm, for example) are likely to play any appreciable role in the mechanism of reflex muscle atrophy.

Adrenal Cortex Hormones↗
PubMed1979

[First experience with retinoid acid derivative Ro 10-9359 in the treatment of viral epithelioma].

Two patients with extensive verrucae plantares have been treated successfully with the retinoic acid derivative Ro 10-9359. Both patients were practically unable to walk due to widespread involvement of the plantae pedium. In a second series of 12 patients with verrucae vulgares this form of therapy produced unsatisfactory results. In 2 further patients with verrucae plantares healing was achieved in one, and also in a patient with verrucae planae. A patient with verrucae periunguales did not react to the treatment. The dosage was gradually increased to above the normal value of 1.0 mg/kg body weight per day, according to individual tolerance. The aim was to reach a dose of over 1.5 mg/kg body weight per day. The side effects were therefore impressive and interruption or termination of therapy was often necessary. However, new side effects have not been observed with this high dosage and this new indication, apart from psoriasiform dermatitis and an intermittent vegetative disturbance, the latter without clear evidence of a causal relation to the Ro 10-9359 medication. Pathological liver values have not been observed. Treatment with retinoid appears to be appropriate in cases with verrucae plantares, especially where conventional methods do not prove satisfactory.

Adolescent↗
PubMed1976

Lateral diffusion, order parameter and phase transition in phospholipid bilayer membranes containing tocopheryl acetate.

Lateral diffusion coefficient and order parameter measurements were made with pyrene excimer optical probes and fatty acid spin label probes respectively in pure dipalmitoyl phosphatidylcholine membranes and in membranes doped with tocopheryl acetate. The investigation shows, that the lateral diffusion coefficient for pyrene in dipalmitoyl pholphatidylcholine membranes is decreased whereas the order parameter of the fatty acid chains is slightly increased in the inner part of the membranes by the addition of tocopheryl acetate. The fluid-solid equilibrium phase diagram of dipalmitoyl phosphatidylcholine/tocopheryl acetate mixed membranes has been constructed from the measurements of the partition of (2,2,6,6-tetramethylpiperdine-1-oxyl) TEMPO spin labels between lipid and aqueous regions as function of temperature. In the membranes tocopheryl acetate induces a strong broadening of the temperature range of the phase transition. At low tocopheryl acetate concentrations dipalmitoyl phosphatidylcholine and tocopheryl acetate seem to be completely miscible in the solid and in the liquid crystalline state.

Binding Sites↗
PubMed1978

The course of the assembly of ribosomal subunits in yeast.

The course of the assembly of the various ribosomal proteins of yeast into ribosomal particles has been studied by following the incorporation of radioactive individual protein species in cytoplasmic ribosomal particles after pulse-labelling of yeast protoplasts with tritiated amino acids. The pool of ribosomal proteins is small relative to the rate of ribosomal protein synthesis, and, therefore, does not affect essentially the appearance of labelled ribosomal proteins on the ribosomal particles. From the labelling kinetics of individual protein species it can be concluded that a number of ribosomal proteins of the 60 S subunit (L6, L7, L8, L9, L11, L15, L16, L23, L24, L30, L32, L36, L40, L41, L42, L44 and L45) associate with the ribonucleoprotein particles at a relatively late stage of the ribosomal maturation process. The same was found to be true for a number of proteins of the 40 S ribosomal subunit (S10, S27, S31, S32, S33 and S34). Several members (L7, L9, L24 and L30) of the late associating group of 60-S subunit proteins were found to be absent from a nuclear 66 S precursor ribosomal fraction. These results indicate that incorporation of these proteins into the ribosomal particles takes place in the cytoplasm at a late stage of the ribosomal maturation process.

Cell Nucleus↗
PubMed1975

Purification, structure and properties of the respiratory nitrate reductase of Klebsiella aerogenes.

1. The respiratory nitrate reductase of Klebsiella aerogenes was solubilized from the bacterial membranes by deoxycholate and purified further by means of gel chromatography in the presence of deoxycholate, and anion-exchange chromatography. 2. Dependent on the isolation procedure two different homogeneous forms of the enzyme, having different subunit compositions, can be obtained. These forms are designated nitrate reductase I and nitrate reductase II. Both enzyme preparations are isolated as tetramers having sedimentation constants (s20,w) of 22.1 S and 21.7 S for nitrate reductase I and II, respectively. The nitrate reductase I tetramer has a molecular weight of about 106. 3. In the presence of deoxycholate both enzyme preparations dissociate reversibly into their respective monomeric forms. The monomeric form of nitrate reductase I has a molecular weight of about 260 000 and a sedimentation constant of 9.8 S. For nitrate reductase II these values are 180 000 and 8.5 S, respectively. 4. Nitrate reductase I consists of three different subunits, having molecular weights of 117 000; 57 000 and 52 000, which are present in a 1:1:2 molar ratio, respectively. Nitrate reductase II contains only the subunits with a molecular weight of 117 000 and 57 000 in a equimolar ratio. 5. Treatment at pH 9.5 in the presence of deoxycholate and 0.05 M NaCl or ageing removes the 52 000 Mr subunit from nitrate reductase I. This smallest subunit, in contrast to the other subunits, is a basic protein. 6. The 52 000 Mr subunit has no catalytic function in the intramolecular electron transfer from reduced benzylviologen to nitrate. However, it appears to have a structural function since nitrate reductase II, which lacks this subunit, is much more labile than nitrate reductase I. Inactivation of nitrate reductase II can be prevented by the presence of deoxycholate. 7. The spectrum of the enzyme resembles that of iron-sulfur proteins. No cytochromes or contaminating enzyme activities are present in the purified enzyme. Only reduced benzylviologen was found to be capable of acting as an electron donor. 8. p-Chlormercuribenzoate enhances the enzymatic activity at concentrations of 0.1 mM and lower. At higher p-chlormercuribenzoate concentrations the enzymatic activity is inhibited non-competitively with either nitrate or benzylviologen as a substrate. The inhibition is not counteracted by cysteine.

Cell Membrane↗
PubMed1975

Characterization of the respiratory nitrate reductase of Klebsiella aerogenes as a molybdenum-containing iron-sulfur enzyme.

1. In respiratory nitrate reductase I of Klebsiella aerogenes, 0.24 atom of molybdenum, eight iron-sulfur groups and four tightly bound, non-heme iron atoms per molecule of enzyme (Mr 260 000) are found. 2. EPR spectra at 83 degrees K of oxidized and reduced nitrate reductase I show complex lines at g = 2.02 and g = 1.98, which are more intense in the reduced than in the oxidized enzyme. The resonances, the shape and intensity of which are rather temperature insensitive, are attributed to two species of paramagnetic molybdenum. In dithionite-reduced enzyme all these lines are saturated at the same microwave power of 15 mW. This is not the case in oxidized enzyme, where the resonance at g = 2.02 is hard to saturate. Addition of nitrate to dithionite-reduced reductase I decreases the intensity of the EPR lines to about that of oxidized enzyme. The participation of molybdenum in the electron transfer process has been discussed. 3. At 18 degrees K the oxidized enzyme exhibits an axial-symmetrical signal with g parallel = 2.10 and g = 2.03, and a signal with unknown symmetry at g = 2.015. Upon reduction by dithionite, a ferredoxin type of signal is observed with g values at 2.05, 1.95 and 1.88, while the g = 2.015 signal disappears. Reoxidation by nitrate causes a concomitant disappearance of the ferredoxin type of signal and reappearance of the g = 2.015 signal; hence iron-sulfur centres participate in the transfer of electrons to nitrate. 4. Nitrate reductase II, containing only two (Mr 117 000 and 57 000) of the three subunits found in nitrate reductase I and lacking the tightly bound iron, does not exhibit the axial-symmetrical signal (g = 2.10 and 2.03). Thus, it suggested that this signal in nitrate reductase I stems from an iron centre in the low-molecular weight subunit (Mr 52 000). 5. Inhibition studies confirm the participation of metals in the transfer of electrons from reduced benzylviologen to nitrate and show that the binding sites for these substrates are different.

Binding Sites↗
PubMed1979

Purification and characterization of the respiratory nitrate reductase of Bacillus licheniformis.

1. Respiratory nitrate reductase of Bacillus licheniformis was extracted from the bacterial membranes by treatment with deoxycholate and purified to a homogeneous state by means of gel chromatography and anion-exchange chromatography. 2. The enzyme (Mr = 193,000, s20, w = 8.6) consists of two subunits, having apparent molecular weight of 150,000 (alpha subunit) and 57,000 (beta subunit), which are present in an equimolar ratio. It does not contain carbohydrate. Ageing of the enzyme appears to result in splitting of the polypeptide chains at specific sites followed by dissociation and reassociation of the digestion products in various combinations. 3. In contrast to Klebsiella aerogenes repiratory nitrate reductase, which is isolated in a tetrameric form that can be reversibly dissociated into a monomeric form by detergents, B. licheniformis nitrate reductase, after isolation, is always present in a monomeric form. This property is related to the difference in membrane localization of the enzyme in the two organisms. 4. B licheniformis nitrate reductase contains 6.9 atoms of non-heme iron, 6.7 atoms of acid-labile sulfide and 0.93 atoms of molybdenum per molecule of enzyme. The molybdenum seems to be part of a low-molecular weight peptide Mo-cofactor) to which it may be bound by interaction with thiol-groups. 5. Antiserum against the native enzyme contains antibodies against both subunits as well as the Mo-cofactor. The Mo-cofactor does not have any antigenic determininants in common with either the alpha or the beta subunit. Also neither subunit cross-reacts with antiserum against the other subunit. Whereas the respiratory nitrate reductases from K. aerogenes and Escherichia coli are immunologically related, the native enzyme from B. licheniformis does not show any cross-reaction with antiserum prepared against either the K. aerogenes or the E. coli enzyme.

Bacillus↗
PubMed1978

Biosynthesis of a hypermodified nucleotide in Saccharomyces carlsbergensis 17S and HeLa-cell 18S ribosomal ribonucleic acid.

The biosynthesis of a hypermodified nucleotide, similar to or identical with 3-(3-amino-3-carboxypropyl)-1-methylpseudouridine monophosphate, present in Saccharomyces carlsbergensis 17S and HeLa-cell 18S rRNA, was investigated with respect to the sequence of reactions required for synthesis and their timing in ribosome maturation. In both yeast and HeLa cells methylation precedes attachment of the 3-amino-3-carboxypropyl group. In yeast the methylated precursor nucleotide was tentatively characterized as 1-methylpseudouridine. This precursor nucleotide was demonstrated in both 37S and most of the cytoplasmic 18S pre-rRNA (rRNA precursor) molecules. The synthesis of the hypermodified nucleotide is completed just before the final cleavage of 18S pre-rRNA to give 17S rRNA, so that the final addition of the 3-amino-3-carboxypropyl group is a cytoplasmic event. Comparable experiments with HeLa cells indicated that formation of 1-methylpseudouridine occurs at the level of 45S RNA and addition of the 3-amino-3-carboxypropyl group occurs in the cytoplasm on newly synthesized 18S RNA.

Base Sequence↗
PubMed1978

Modification of yeast ribosomal proteins. Phosphorylation.

Two-dimensional polyacrylamide-gel electrophoretic analysis of yeast ribosomal proteins labelled in vivo with 32PO43- revealed that the proteins S2 and S10 of the 40S ribosomal subunit, and the proteins L9, L30, L44 and L45 of the 60S ribosomal subunit, are phosphorylated in vivo. Most of the phosphate groups appeared to be linked to serine residues. Teh number of phosphate groups per molecule of phosphorylated protein species ranged from 0.01 to 0.79. Since most of the phosphorylated ribosomal proteins appear to associate with the pre-ribosomal particles at a very late stage of ribosome assembly, phosphorylation is more likely to play a role in the functioning of the ribosome than in its assembly.

Amino Acids↗
PubMed1978

Modification of yeast ribosomal proteins. Methylation.

Two-dimensional polyacrylamide-gel electrophoretic analysis of yeast ribosomal proteins uniformly labelled in vivo with [methyl-3H]methionine and [1-14C]methionine revealed that four ribosomal proteins are methylated, i.e. proteins S31, S32, L15 and L41. Lysine and arginine appear to be the predominant acceptors of the methyl groups. The degree of methylation ranges from 0.09 to 0.20 methyl group per modified ribosomal protein species.

Amino Acids↗
PubMed1979

Analysis of histones from the yeast Saccharomyces carlsbergensis.

Basic chromosomal proteins were isolated from the chromatin of the yeast Saccharomyces carlsbergensis by extraction with H2SO4 and were purified by ion-exchange chromatography. Electrophoresis of the purified fraction on acetic acid/urea gels revealed the presence of four main components. These four proteins were identified as histones H2A, H2B, H3 and H4 on the basis of their amino acid composition, molecular weight and solubility properties, all of which are very similar to the corresponding properties of the various histone proteins from other eukaryotic organisms. A fifth basic protein could be isolated from yeast chromatin by extraction with HClO4. The available evidence indicates this protein to be an H1-type histone. Yeast thus appears to contain a complete set of histone proteins which are strongly homologous to the histones occurring in higher eukaryotes.

Amino Acids↗
PubMed2026

Maize Gametophytic factor loci Ga3 through Ga11 modify reproductive barriers.

Gametophytic factor (Ga) barriers are maize (Zea mays ssp. mays) reproductive barriers controlled by molecular incompatibilities between pollen and silks. Twelve distinct Ga loci have been identified in maize populations since the first genetic evidence of a Ga barrier was reported in 1901. Of the twelve, however, only three have been validated by modern molecular, functional and genomic studies: Ga1, Ga2, and Tcb1. The remaining "higher" Ga loci, spanning Ga3 to Ga11, were reported in the historical literature, but their associated phenotypes segregated in unexpected ways or disappeared over subsequent generations. Here we introduce and explore the hypothesis that the higher Ga loci represent modifiers of Ga1, Ga2, and Tcb1 barrier functions. By revisiting the historical literature, we found that barrier phenotypes fall into two phenotypic and functional categories. Phenotypically, the two categories represented healthy pollen with a silk-length effect and unhealthy pollen without a silk-length effect. These phenotypic categories were supported by genomic data; we identified candidate genes in each higher Ga locus by comparing historical linkage mapping data to the corresponding genomic sequence of maize reference line B73. We discovered candidate genes related to two broad pathways: pollen tube growth and RNA-directed DNA methylation. We conclude that the past century of evidence aligns with our hypothesis that maize loci Ga3 through Ga11 modify rather than directly control Ga barriers. This brief investigation provides a starting point for geneticists and evolutionary biologists to explore how strong reproductive barriers are shaped by epistatic interactions.

Epistasis↗
PubMed1977

Sequence of the 3'-terminal 21 nucleotides of yeast 17S ribosomal RNA.

The sequence of the 3'-terminal 21 nucleotides of 17S ribosomal RNA from the yeast Saccharomyces carlsbergensis has been determined to be (Y)G-m62A-m62A-C-U-C-G-C-G-G-A-A-G-G-A-U-C-A-U-U-AOH. This sequence shows extensive homology with the 3'-terminal sequence of 16S rRNA from Escherichia coli including the presence of the two adjacent N6-,N6-dimethyladenosines observed in the small subunit rRNA of eukaryotes as well as of many prokaryotes.

Base Sequence↗
PubMed1978

Genetic organization of the ribosomal transcription units of the yeast Saccharomyces carlsbergensis.

The genetic organization of the multiple ribosomal transcription units (RTUs) on the genome of the yeast Saccharomyces carlsbergensis was studied by electron microscopy of purified ribosomal DNA hybridized to 26S rRNA using the R-loop technique (Thomas, M., White, R.L. and Davis, R.W. (1973) Proc. Natl. Acad. Sci. U.S. 73, 2294-2298). Plasmid pBR 322, the molecular weight of which is known, was used as a standard for converting contour length of double-stranded DNA into molecular weight. The 140 yeast RTUs were found to be arrayed in tandem repeats, each repeat containing at most 0.4 X 10(6) D (about 6% of the length of the RTU) of non-transcribed spacer DNA. The repeats, in turn, are arranged in a number of clusters separated by much longer stretches of non-ribosomal DNA.

Genes↗
PubMed1979

The primary transcript of the ribosomal repeating unit in yeast.

Endgroup analysis of 37S ribosomal precursor RNA from Saccharomyces carlsbergensis has revealed that the major 5' endgroup is ppA-Up, with a molar yield of 0.8. This shows that most, if not all, 37S RNA molecules have preserved a transcriptional initiation sequence. Analysis of the 3' terminus of 37S RNA has shown the presence of a uridine rich oligonucleotide, tentatively identified as U6-8-A-NOH. This long stretch of uridines at the 3' end of 37S RNA may represent a transcriptional termination site. The two sets of data on the terminal sequences suggest that 37S ribosomal precursor RNA, if not already spliced, is a primary transcription product. Since the 3' terminus of 26S rRNA, U-U-U-G-UOH., appears to be clearly different from the 3' end of 37S RNA, we conclude that 37S ribosomal precursor RNA contains additional nucleotides 3'-distal to the 26S rRNA sequence.

Base Sequence↗