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Biomedical subjects

R M Franklin

Publications and source records attributed to R M Franklin.

At least 109 records · Page 6Linked to original sources
PubMed1977

Epidemic caprine keratoconjunctivitis: recovery of Mycoplasma conjunctivae and its possible role in pathogenesis.

Clinical, microbiological, serological, histological, and therapeutic aspects of two separate outbreaks of caprine keratoconjunctivitis are described. The disease was characterized by a high rate of contagion, rapid onset, intense lacrimation, conjunctival hyperemia, and corneal opacity with neovascularization. In addition, many of the animals developed respiratory illness during the second epidemic. The only organism consistentlyisolated was Mycoplasma conjunctivae. A total of 23 strains were isolated from 18 inflamed conjunctivae, one normal conjunctiva, and the nasal secretions of four goats with concomitant respiratory illness. The convalescent sera of goats in the first outbreak had neutralizing antibody titers to M. conjunctivae that ranged from 1:32 to 1:256. In the milder second outbreak the antibody titers ranged from 1:4 to 1:32 in animals with only ocular disease and from 1:4 to 1:64 in animals with only respiratory disease. Whereas little change was noted in antibody titers of goats with only localized eye disease, 43% of the goats with respiratory disease showed significant fourfold rises. The histological picture was consistent with acute corneal infection. Animals requiring antibiotic treatment appeared to respond favorably to a combination of oxytetracycline and polymyxin B, but not to penicillin. These findings suggest that M. conjunctivae is one cause of epidemic caprine keratoconjunctivitis.

Animals↗
PubMed1977

Epidemic caprine keratoconjunctivitis: experimentally induced disease with a pure culture of Mycoplasma conjunctivae.

The induction of caprine keratoconjunctivitis by the subconjunctival inoculation of a cloned culture of Mycoplasma conjunctivae is described. The clinical course of the experimental disease was similar to that noted in naturally occurring outbreaks of "pink-eye" among goats, and biopsies of inflamed conjunctivae showed similar histological response. M. conjunctivae was consistently recovered from the inflamed conjunctival tissues of inoculated animals that developed ocular disease, thus fulfilling Koch's postulates and establishing this organism as an etiological agent of caprine keratoconjunctivitis. Immunological studies suggested that cellular immune mechanisms may play a role in protecting animals from disease produced by this mycoplasma.

Animals↗
PubMed1976

Structure and assembly of lipid-containing viruses, with special reference to bacteriophage PM2 as one type of model system.

The simpler lipid-containing viruses (influenza, Semliki Forest, PM2) may have a phospholipid bilayer sandwiched between an outer shell of protein and an internal nucleocapsid possessing helical or icosahedral symmetry. Extensive physical and chemical studies have enabled us to form a more detailed picture of the structure of bacteriophage PM2 and controlled stepwise degradation of the virion has helped us to localize the four viral proteins. The surface protein (II) of PM2 is basic and interacts with the acidic phosphatidylglycerol of the bilayer to stabilize the membrane. The nucleocapsid protein (III) has proteolipid characteristics and may interact with the phospholipids in a hydrophobic fashion. The spikes are formed from protein I and the fourth protein (IV) is closely associated with the DNA. It is possible to reassemble the virus by reversing the degradation steps. Assembly has been especially useful in revealing the processes whereby the proteins and lipids interact to form the bilayer. Furthermore, results of in vivo studies of phospholipid synthesis and both in vivo and in vitro studies of viral protein synthesis have enabled us to form a reasonably complete picture of the biosynthesis of PM2.

Bacteriophages↗
PubMed1976

Identification of acyl phosphatidylglycerol as a minor phospholipid of Pseudomonas BAL-31.

Compound X, a minor phospholipid of Pseudomonas BAL-31 and bacteriophage PM2, has been identified as X-3-phosphatidyl-1'-(3'-acyl)-glycerol, or acyl phosphatidylglycerol. The water-soluble product obtained by mild alkaline hydrolysis showed the same RF value as that of glycerophosphoryl-glycerol. The chemical analysis gave the ratio 1 : 3 : 2 for phosphate-acyl ester-glycerol. The position of the third acyl group was determined by nuclear magnetic resonance techniques.

Bacteriophages↗
PubMed1976

Phase transitions in the membrane of a marine bacterium, Pseudomonas BAL-31.

An unsaturated fatty acid auxotroph, strain UFA, isolated from the marine pseudomonad Pseudomonas BAL-31, host cell of the lipid-containing bacteriophage PM2, was grown in media supplemented with different unsaturated fatty acids. Under these conditions the fatty acid composition of the cell could be altered drastically. The phase transition in the native membrane and in the extracted lipids was analyzed by electron spin resonance using a nitroxide spin probe. Membranes prepared from strain UFA grown in cis16:1 or trans16:1 showed one transition at 9.4 degrees C and 12.4 degrees C respectively. Extracted lipids in both cases had almost the same transition temperature as that of the intact membrane. Membranes prepared from Pseudomonas BAL-31 had one transition at approximately 12 degrees C, on the other hand there was no clear cut phase transition using extracted lipids. Replication of bacteriophage PM2 took place below the transition temperature of the membrane lipids in the case where strain UFA was grown in tran16:1. Other cases were not studied.

Bacteriophages↗
PubMed1976

Allergy to insect stings. II. Phospholipase A: the major allergen in honeybee venom.

In order to determine the proteins of major allergenic importance in honeybee venom (Apis mellifera) it was chromatographed on G-50 Sephadex. The four major protein peaks eluted were identified as hyaluronidase, phospholipase, melittin, and apamin. Testing these preparations on the leukocytes of 6 honeybee-sensitive patients, with the in vitro method of histamine release, revealed that all individuals were most sensitive to phospholipase A. IgE antibodies against phospholipase A (RAST) were found in the sera of honeybee-sensitive patients and IgG antibodies to this venom component were found in the sera from beekeepers and venom-treated patients. Melittin appeared to be allergenic in several patients, but the results were variable and were possibly due to contamination with phospholipase. All patients were insensitive to the hyaluronidase and apamin preparations. We conclude that phospholipase A is the major allergen of honeybee venom and, since this protein is readily available, it should be useful for diagnostic and therapeutic studies as well as for the standardization of materials used in the management of honeybee-sensitive patients.

Allergens↗
PubMed1976

The stability of short ragweed pollen extract as measured by skin test and antigen E.

A short ragweed pollen extract stored at 4 degrees C was shown to retain its skin reactivity for 18 mo, although 60% of the antigen E was lost. When stored at higher temperatures, the extracts had a markedly reduced skin reactivity for some individuals, but retained full reactivity in others even though the antigen E was markedly diminished. Thus, some ragweed-sensitive individuals are very sensitive to antigen E, which is heat-labile, but some have a major sensitivity to other allergens, which are heat-stable. During the 18-mo course of this study, skin test reactions to a similar extract did not show significant variability.

Adolescent↗
PubMed1976

Structure and synthesis of a lipid-containing bacteriophage. Purification, chemical composition, and partial sequences of the structural proteins.

The four structural proteins of the lipid-containing bacteriophage PM2 have been purified by dissociation of the virus in the presence of acetic acid followed by a combination of gel filtration and ion-exchange chromatography in the presence of sodium dodecylsulfate and guanidine hydrochloride. Amino acid analyses of each of the proteins were performed and correlated with the properties and functions of the proteins. Protein I has the highest polarity and is the only water-soluble protein. Protein II has a rather high polarity and hydrophobicity index and probably interacts electrostatically and hydrophobically with the bilayer. Proteins III and IV have low polarities and possess the solubility properties of proteolipids. At least protein III and perhaps also protein IV may interact with the bilayer. No fatty acids are covalently linked to these proteins. Tryptic fingerprints showed that proteins I and II contain a high proportion of hydrophobic peptides, but especially protein I also contains a large number of hydrophilic peptides. Proteins III and IV have relatively few hydrophobic peptides despite their relatively high hydrophobicity. Protein IV has two distinct regions, as shown by partial sequence studies. Basic amino acids at the N-terminus would serve for interaction with the viral DNA, the following hydrophobic sequence might interact with protein III or with the bilayer.

Amino Acid Sequence↗
PubMed1976

Drug flashbacks. II. Some additional findings.

A subsample was drawn from an earlier collection of data in order to answer a number of questions related to "acid" (LSD, STP) flashbacks. Acid users who reported flashbacks also reported significantly more marijuana use than those who did not; the two groups did not differ on use of other drugs, including acid. Simple correlations and multiple regression analyses both showed extent of marijuana use to be the only drug variable significantly related to acid flashbacks. No optimal combination of marijuana and acid improved flashback prediction. Among acid users, correlations between amounts of use for various drugs were high and significant, excepting only the marijuana-acid correlation.

DOM 2,5-Dimethoxy-4-Methylamphetamine↗
PubMed1975

Structure and synthesis of a lipid-containing bacteriophage. Chemical modifications of bacteriophage PM2 and the resulting alterations in acyl-chain motion in the PM2 membrane.

The nucleocapsid proteins of bacteriophage PM2 and the inner lamella of the lipid bilayer, containing most of the phosphatidlethanolamine residues, were selectively cross-linked in the presence of 0.1-0.5% glutaraldehyde, 5 mM dimethylsuberimidate, or 0.05% toluene 2,4-diisocyanate. The biological activity (p.f.u.) of PM2 modified by these reagents decreased 10(6)-fold in all cases. The spike and coat proteins were selectively cross-linked in the presence of 7.5 mM N,N'-p-phenylenedimaleimide. The biological activity of virus modified by this reagen was unaffected. The electron paramagnetic resonance spectra of fatty acid spin labels incorporated into native and chemically modified viral membranes were qualitatively similar but show quantitative differences. Fixation with glutaraldehyde increased the rigidity of the membrane while Triton X-100 induced a more flexible structure. There was no change in the electron paramagnetic resonance spectrum of virus treated with N,N'-p-phenylenedimaleimide, however.

Bacteriophages↗
PubMed1975

Structure and synthesis of a lipid-containing bacteriophage. A polynucleotide-dependent polynucleotide-pyrophosphorylase activity in bacteriophage PM2.

A polymerase activity is associated with protein IV, a protein which is associated with the DNA in bacteriophage PM2. The native enzyme unit is probably a dimer. Manganese ions are required for the polymerisation reaction and there is a well-defined Mn2+ optimum at 2.5 mM. The pH optimum is at 8.1, the temperature optimum at 28 degrees C. The activity is a polynucleotide-pyrophosphorylating reaction in the presence of ribo- or deoxyribonucleoside triphosphates. The polymerisation reaction is stimulated in the presence of nuclei- acids or polynucleotides as effectors. The product is not covalently linked to the effector.

Bacteriophages↗
PubMed1975

Structure and synthesis of a lipid-containing bacteriophage. The molecular weight and other physical properties of bacterophage PM2.

Several physical and chemical parameters of bacteriophage PM2 have been measured. The sedimentation constant was determined to be s-20,w=293 S. The buoyant density in sucrose at 20 degrees C was 1.24 g cm+-3 and in CsCl at 25 degrees C was 1.29 g cm-3. The high-speed equilibrium centrifugation method of Yphantis (1964) was used to measure the molecular weight of PM2. The necessary auxiliary parameters were also determined. A value of 0.771 plus or minus 0.005 cm-3 g-1 for the apparent specific volume at constant chemical potential in 1 M sodiium chloride has been obtained by pycnometry; the viral concentration was determined using the absorption coefficient at 260 nm (4.60 plus or minus 0.10 cm-2 mg-1), which in turn was calculated from the phosphorous content of the virus (17.89 plus or minus 0.28 mu-g of P per mg dry weight dry weight of virus). The molecular weight of PM2 determined with these parameters is (44.1 plus or minus 1.2 x 10-6). From the phosphorous content of the virus, the percentage of phosphorous known to be in its DNA (Camerini-Otero and Franklin, 1972), and the molecular weight of the bacteriophage, we have calculated a molecular weight for PM2 DNA of 6.26 x 10-6, which confirms values determined using empirical relationships.

Bacteriophages↗