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PubMed1978

Plasminogen activators of psoriatic scale extracts. Separation of two plasminogen activators by isoelectric focusing.

Psoriatic scale extracts were fractioned by using polyacrylamide gel isoelectric focusing (PAGIF) and preparative electrofocusing in granulated gel (PEGG). The largest protein fraction was found with Ip at pH 4.8--5.0, and the main protein bands within pH values 4.0--7.5. PEGG separated three main fractions with plasminogen activator or trypsin-like esterase activity with isoelectric points at pH 6.5--6.6, 5.4--6.2 and 4.9. The enzyme with Ip at pH 6.5--6.6 hydrolyzed trypsin substrates but lacked plasminogen activator capacity. The enzyme with Ip at pH 5.4--6.2 showed both activities but the third enzyme with plasminogen activator capacity with Ip at pH 4.9 was without detectable esterolytic activity towards substituted basic amino acid esters. The third enzyme was prominent in KCl-extract and the second in KSCN-extract. The first was equal in both extracts. The enzyme with Ip at pH 4.9 is possibly of bacterial origin while the plasminogen activator with Ip at pH 5.4--6.2 extracted in KSCN probably represents tissue activator of psoriatic scales.

Humans↗

PubMed1978

Unilateral chronic pyelonephritis and hypertension: coincidental or causal relationship?

Three patients with well documented unilateral chronic pyelonephritis (UCP) of bacterial origin, one hypertensive and two normo-tensive, were presented. Removal of the contracted kidney in the hypertensive patient did not eradicate the hypertension. An attempt was made to define UCP as closely as possible. The clinical, roentgenologic, bacteriologic, functional and pathologic criteria of UCP was described. But, as other conditions may mimic the roentgenologic, functional and pathologic picture of UCP, a history of recurrent urinary tract infection accompanied by a documented unilateral renal bacteriuria is the basic requirement for a sustained diagnosis of UCP. In view of these more exacting criteria in the diagnosis of UCP, and its water and salt-losing functional pattern, UCP is a rare cause of hypertension, in the majority of cases the association of UCP with hypertension is merely coincidental.

Adolescent↗

PubMed1979

Recurrent herpetic angular blepharitis in an adult.

A 36-year-old man had several episodes of left angular blepharoconjunctivitis associated with upper respiratory infections, herpes labialis, or emotional stress. The clinical diagnosis had always been a blepharitis of bacterial origin. During the last attack, cytologic examination of a scraping obtained from an eyelid pustule vesicle revealed multinucleated keratinocytes, diagnostic of a herpetic infection. Virologic studies proved that herpes simplex virus type 1 was the causal agent.

Adult↗

PubMed1975

Paramagnetic spin label interactions with the envelope of a group A arbovirus. Lipid organization.

Electron paramagnetic resonance observations were made on nitroxide spin- labeled molecules which were bound to the TC-83 vaccine strain of Venezuelan equine-encephalomyelitis virus. Paramagnetic resonance parameters derived from the observations and their dependence on sample temperature were similar but not identical to those which have been reported for these labels dissolved in lipid bilayer membranes of mammalian and bacterial origin. The data has a mechanical rigidity substantially greater than that of bilayers in cellular membranes. A model is presented which assumes the location of the lipid bilayer outside the nucleoprotein capsid and inside a spherical layer of envelope proteins. The model is in accord with Harrison's X-ray diffraction results for Sindbis virus. The model is discussed in terms of its implications with respects to the role played by lipid in viral maturation and infectivity.

Animals↗

PubMed1976

Isolation and characterization of four peptide hydrolases from the brush border of rat intestinal mucosa.

Peptide hydrolases (EC 3.4.-.-) were solubilized from purified brush borders of rat intestinal mucosa by papain digestion. Three peptide hydrolases, I, II, and III, with different substrate specificities were isolated by means of DEAE-cellulose chromatography and preparative acrylamide gel electrophoresis. On repeat preparative acrylamide gel electrophoresis under slightly different conditions, enzyme II was resolved into two proteins, IIa and IIb, with vary similar, possibly identical, substrate specificities. Efforts to discover additional brush border peptide hydrolases revealed none. Studies using more than 50 substrates showed that enzyme I was most active against Met-Met, Met-Ala, and Met-Phe while enzyme II was most active against Phe-Gly, Phe-Ser, and Leu-Gly-Gly, and enzyme III most rapidly hydrolyzed Gly-Leu, Leu-Gly, and Met-Gly. Efforts to discover substrates which are highly discriminating for each enzyme were partly successful. Thus, a number of substrates including leucine amide, leucyl-beta-naphthylamide and Phe-Asp were hydrolyzed almost exclusively (95% or more) by enzyme II while Gly-Leu was similarly specific for enzyme III. No substrate highly discriminating for enzyme I was discovered. Ion-exchange chromatography resulted in increases in specific activity of 10- and 120-fold for enzymes II and III, respectively. By sequential use of ion-exchange chromatography and preparative acrylamide gel electrophoresis, each of the three enzymes was partially purified to the point that they were free of contaminating disaccharidases and enzymes I and II gave single dense bands on analytical acrylamide gel electrophoresis while enzyme III gave a single dense band plus one additional faint protein band. Under appropriate conditions, analytical gel electrophoresis also resolved enzyme II into two bands with enzyme activity. The three enzymes were isolated from intestinal brush borders of germ-free rats indicating that none of the enzymes is of bacterial origin. With Phe-Gly as substrate, pH optima for enzymes I, II, and III were 8.0, 8.0, and 8.5, respectively. Molecular weights determined by gel filtration were 283 000, 284 000, and 134 000, respectively. Studies of activation by metal ions and inhibition by metal ion chelators suggested that the activity of each of the enzymes is dependent on a relatively tightly bound metal cofactor. Peptide hydrolases of the intestinal mucosa play an essential role in protein digestion. The studies presented here help to clarify the total number and substrate specificities of these enzymes in the rat brush border.

Animals↗

PubMed1976

Covalently closed minicircular DNA associated with Acetabularia chloroplasts.

When Acetabularia cliftonii chloroplast DNA (p = 1.706 g/cm3) is centrifuged in an ethidium bromide-CsCl gradient, the lower band is enriched for DNA with a buoyant density of 1.712 g/cm3 containing small covalently closed circular molecules. The minicircles measure 4.15 +/- 0.30 mum in the closed conformation and 4.35 +/- 0.20 mum in the open conformation. They are not of nuclear or bacterial origin, and appear to exist as independent entities within the chloroplast, although a mitochondrial origin cannot be completely ruled out. No 40-45 mum circles, as found in other chloroplasts, were found in either ethidium bromide-CsCl fraction. None were found in total chloroplast DNA by any of a number of methods tried. Linear molecules up to 200 mum were measured in chloroplast lysates. The main chloroplast genome may consist of very large circular molecules which are broken by even small shear forces.

Acetabularia↗

PubMed1977

Transcription and translation of cloned Drosophila DNA fragments in Escherichia coli.

The expression of three unique DNA fragments from Drosophila melanogaster which have been inserted into Escherichia coli (E. coli) via the plasmid, pSC 101, was studied. The hybrid plasmid DNA molecules containing Drosophila DNA were transformed into the minicell producing strain of E. coli, X1411. Drosophila DNA-directed RNA synthesis was studied by hybridizing newly synthesized RNA isolated from the minicells with various DNA fragments which were immobilized on nitrocellulose filters. RNA was synthesized as readily from the inserted Drosophila DNA as from the original bacterial plasmid, pSC 101. In one case, transcription appeared to be initiated preferentially on one of the two strands of a Drosophila DNA fragment regardless of the orientation of that Drosophila DNA fragment with respect to the pSC 101 sequences. Two of the three Drosophila DNA fragments did not induce the synthesis of new polypeptides in minicells as detected by autoradiography of [35S]methionine-labeled polypeptides on polyacrylamide gels. The third Drosophila DNA fragment caused the synthesis of one additional polypeptide of 29 000 daltons. When an 8200 base pair portion of the third inserted Drosophila DNA (63% OF THE TOTAL Drosophila insertion) was removed by digestion with the restriction enzyme, Eco R1, this new polypeptide was no longer synthesized by minicells containing the remaining Drosophila DNA. When the 8200 base pair fragment was placed back into its parent plasmid as an inversion, the new polypeptide did not reappear. In addition, the presence of some, but not all, of the Drosophila DNA insertions affected the relative synthesis of the six polypeptides coded for by the parent plasmid, pSC 101.

Animals↗

PubMedDate not supplied

Auto anti-Kpb associated with weakened antigenicity in the Kell blood group system: a second example.

An 84-year-old woman with intestinal bleeding had marked reduction of red blood cell antigenicity in the Kell system, and a positive direct antiglobulin test caused by auto-anti-Kpb. KX antigen activity of her cell was increased, an observation which supports the belief that KX marks a precursor structure utilized in the normal Kell biosynthetic pathway. It is postulated that reduced Kell antigenicity was an acquired change that resulted from enzymatic degradation, possibly of bacterial origin.

Adolescent↗

PubMed1976

Artificial rearing of pigs. 5. The effect of different proportions of beef tallow or soya-bean oil and dried skim milk in the diet on growth, feed utilization, apparent digestibility and carcass compostion.

1. Diets containing different proportions of skim milk and fat, either beef tallow or soyabean oil, supplemented with fat-soluble vitamins were given to 2-d-old pigs. Each fat source was used in three diets containing approximately 280, 350 and 420 g fat, and 260, 235 and 210 g protein/kg dry matter respectively. 2. The diets were given as a milk containing 200 g solids/l during a 26 d experiment. The pigs were given the diet at hourly intervals according to a scale based on live weight. 3. Increasing the energy content of the diet, with the accompanying decrease in protein content, had no effect on live-weight gain or feed: gain ratio (g feed dry matter/g live-weight gain) (other than a slight reduction in live-weight gain when beef tallow was used), or on nitrogen retention. However, the fat content of the carcass of the 28-d-old pig was increased, and its protein and ash content were decreased. 4. The apparent digestibilities of the fatty acids ranged from 0-96 to 1-00. The faeces from pigs given the soya-bean-oil diets contained some eicosanoic, docosanoic and tetracosanoic acids, presumably of bacterial origin. In general, palmitic and stearic acids were slightly less well digested than oleic and linoleic acids.

Animals↗

PubMed1979

The nutritional toxicity of Phaseolus vulgaris lectins.

In rats fed on beans (Phaseolus vulgaris) the poorly digestible lectins were shown to react with intestinal cells in vivo and to cause a disruption of many of the brush borders of duodenal and jejunal enterocytes. Although depressed to a certain extent, absorption still occurred, probably through the non-disrupted cells of the small intestine. In addition, abnormal absorption of potentially harmful substances, lectin-related or of bacterial origin, could also occur, possibly as a direct effect of the disruption caused by the lectins on the enterocytes. It is suggested that toxicity was the result of ensuing systemic effects, such as for example the observed high N excretion possibly through increased tissue catabolism.

Animals↗

PubMed1975

Inhibition of urease activity by hydroxamic acid derivatives of amino acids.

Hydroxamic acids have been reported to be potent and specific inhibitors of urease (EC 3.5.1.5) activity of plant and bacterial origin. The present investigation was performed on the inhibitory effect of hydroxamic acid derivatives of naturally occurring amino acids on the urease activity of the Jack Bean and the alimentary tracts of rats. Methionine-hydroxamic acid was the most powerful inhibitor (I50=3.9 X 10(-6) M) among nineteen alpha-aminoacyl hydroxamic acids. Phenylalanine-, serine-, alanine-, glycine-, histidine-, threonine-, leucine-, and arginine-hydroxamic acids followed, in order of decreasing inhibitory power. The inhibition proceeded with time at a comparable rate to fatty acyl hydroxamic acid inhibition. The I50 values of alpha-aminoacyl hydroxamic acids were found to be almost equal to those of the corresponding fatty acyl hydroxamic acids. This fact shows that the alpha-amino group did not affect inhibitory power. However, aspartic-beta-, lysine-, and glutamic-gamma-hydroxamic acids, in descending order, were much less inhibitory, probably due to the presence of a carboxyl or omega-amino group. Furthermore, the pH optimum of the inhibition shifted to lower pH in the presence of a carboxyl group, and to a higher pH in e presence of an amino group. The results suggest that the dissociation of an acidic or a basic group reduces the inhibitory power of hydroxamic acid. Hydroxamic acid inhibits urease activity with strict specificity, excpet for aspartic-beta-hydroxamic acid, which inhibited asparaginase competitively. Hydroxamic acid derivatives of amino acids inhibited not only the urease activity of the Jack Bean, but also that of the caecum and ileum parts of the rat intestine.

Amino Acids↗

PubMed1979

Properties of a gonococcal inhibitor produced by Escherichia coli.

Strains of Escherichia coli can inhibit the in vitro growth of Neisseria gonorrhoeae. One E. coli strain released a potent agar-diffusible gonococcal growth inhibitor which was extracted and assayed in an agar well assay system. The culture conditions necessary to produce the inhibitor were determined. The inhibitor was bacteriostatic, in most cases, for N. gonorrhoeae. Based on ultrafiltration and column chromatography, the inhibitor appeared to have a molecular weight in the range of 1200 to 2000. Evidence that the molecule contained charged sites was obtained by membrane binding and column chromatography. The inhibitor was stable to extremes of heat, cold and pH. It was not volatile or susceptible to proteolytic enzymes, lysozyme, lipase, DNAase, RNAase or certain chelating agents. Its activity was completely blocked by ferric ammonium citrate. This inhibitor is dissimilar to previously reported gonococcal inhibitors of bacterial origin.

Escherichia coli↗

PubMed1976

Isolation and characterization of Agrobacterium tumefaciens mutants affected in the utilization of octopine, octopinic acid and lysopine.

Using an enrichment procedure, mutant strains of Agrobacterium tumefaciens were isolated that lacked the ability to utilize octopine as a nitrogen source. Of 55 such isolates, 44 were unable to utilize several amino acids; the remaining 11 strains were altered solely in their ability to utilize octopine, octopinic acid and lysopine. It is concluded that only the latter were plasmid mutations. Among them, there was a high, but no absolute, correlation with avirulence. All strains contained the T1 plasmid. All virulent strains showed active transport of octopine when they had previously been grown in medium containing octopine, whereas the avirulent strains failed to show such transport. All the virulent mutants induced tumours containing octopine. The results are discussed in relation to the hypothesis that the genes which code for the octopine synthesizing enzymes in the tumour are of bacterial origin.

Amino Acids, Dicarboxylic↗

PubMed1976

Esterolytic activities of rat intestinal mucosa. 1. Characterization, cellular distribution and subcellular localization of a glycerol-ester hydrolase.

The preferential cellular distribution in the villus tip and the subcellular localization in the endoplasmic reticulum of an intestinal glycerol-ester hydrolase from rat mucosa are described. The enzyme is shown not to be from either pancreatic or bacterial origin; it catalyzes the hydrolysis of short- and medium chain triglycerides and of p-nitrophenylacetate. Contrarily to the specificity found for the pig intestinal lipase (Serrero, Négrel and Ailhaud, 1975), no activity is detectable against acylCoA; a thiolester hydrolase different from the glycerol-ester hydrolase was demonstrated after differential solubilization and chromatographic separation. A high proportion of glycerol-ester hydrolase is present in the intestinal lumen; its possible complementary role in lipid degradation is discussed.

Aging↗

PubMed1976

Pulmonary diseases of cattle in the Kimberley District of Western Australia.

A survey of pulmonary disease in cattle slaughtered in the Kimberley district of Western Australia, incidental to the monitoring of lungs for contagious bovine pleuropneumonia (CBPP), was initiated in 1969. The results of the first 3 years are reported and indicate the complete absence of CBPP, the occurrence of actinobacillosis as the most common pulmonary lesion, the existence of phycomycosis in a few lungs each year, the frequent presence of subacute and chronic bronchopneumonias and interstitial pneumonias possibly as sequelae of actinobacillosis, tuberculosis and the pneumomycoses, and the relatively low incidence of fibrinous and necrotic pneumonias of other bacterial origin.

Actinobacillosis↗

PubMed1978

Comparison of rhapidosomes and asbestos microfibrils.

Rhapidosomers (cylindrical nucleoprotein rods of bacterial origin) show great structural similarity to the microfibrils of chrysotile asbestos when negatively stained and observed with the electron microscope. If the negative stain is omitted, the asbestos retains its structural detail whereas the rhapidosomes appear to be unstructured bodies. When the microscope is adjusted into a selected area diffraction mode, the asbestos shows characteristic electron diffraction patterns whereas the rhapidosomes appear to be amorphous to electron diffraction.

Asbestos↗

PubMed1978

Serological studies of a host range mutant of a lactic streptococcal bacteriophage.

A host range mutant was isolated from a bacteriophage that attacked Streptococcus cremoris 114. The mutant was able to adsorb and grow on S. cremoris 266, where the parent phage could not. The mutant phage was unable to adsorb to the original bacterial host, S. cremoris 114. The change in host range was accompanied by an alteration in the neutralization antigen as shown by a change in neutralization rate by an anti-phage serum. Serum-blocking experiments confirmed the difference in neutralization antigen between parent and mutant phages. The two phages nevertheless had similar complement fixation antigens, confirming that one was a mutant derived from the other. A distinction between complement fixation and neutralization antigens, similar to that found for the coliphages and staphylococcal phages, has therefore been demonstrated for two lactic streptococcal phages.

Adsorption↗

PubMed1975

Regulation of exocellular proteases in Neurospora crassa: metabolic requirements of the process.

To induce exocellular proteolytic enzyme from carbon-starved exponential-phase cells of Neurospora crassa, both a protein substrate and an activating protease of certain specific properties must be present at the same time. The cells must be capable of protein synthesis, since cycloheximide inhibits the process, but cell growth, as determined by increase in cell mass, does not appear to be required. Both soluble (bovine serum albumin, myoglobin) and insoluble protein substrates (collagen, corn zein) will affect protease induction, although certain soluble, globular proteins (egg white globulin, bovine gamma globulin) will not. In most cases, rates of protease induction are proportional to protein concentration, regardless of the nature of the inducing protein. All activating proteases capable of affecting induction in a manner similar to that of N. crassa exocellular protease were of bacterial origin and were exoproteases. Mammalian proteases and peptidases had little or no effect on the induction process.

Cycloheximide↗