Search PubMed⌕ Search

Biomedical subjects

R M Franklin

Publications and source records attributed to R M Franklin.

At least 91 records · Page 5Linked to original sources
PubMed1980

Structure and synthesis of a lipid-containing bacteriophage. Studies on the structure of the bacteriophage PM2 nucleocapsid.

The nucleocapsid of bacteriophage PM2, prepared according to Schäfer et al. [Eur. J. Biochem. 92, 579-588 (1978)], was studied by biochemical and biophysical methods. It was not possible to isolate the lipid-free nucleocapsid. More than 95% of the lipids were associated with the nucleocapsid. The asymmetric distribution of phospholipids across the viral membrane was retained in the nucleocapsid since less than 10% of the phosphatidylethanolamine was accessible to the non-penetrable membrane probe, 2,4,6-trinitrobenzenesulfonate. Micro-dissection of the nucleocapsid with thermolysin demonstrated the asymmetric orientation of core proteins across the nucleocapsid membrane. Protein III was embedded deeply in the lipid bilayer and about 20% of the molecule extended to the exterior. Protein IV interacts with PM2 DNA and is partially in the inner leaflet of the bilayer. Small-angle X-ray scattering studies on the nucleocapsid enabled us to localize the lipid bilayer structure at radii from 20.5 nm to 24.0 nm.

Bacteriophages↗
PubMed1980

Staining and histochemistry of undecalcified bone embedded in a water-miscible plastic.

Undecalcified bone fixed in a variety of fixatives and embedded in a new formulation of 2-hydroxypropyl methacrylate at 4 c has been sectioned at 1 to 5 microns. The embedding mixture contains 2-butoxyethanol as plasticizer and triethyleneglycol dimethacrylate as cross-linker. The accelerator was benzoyl peroxide and the catalyst was N,N-dimethylaniline. With proper embedding and care in sectioning it is possible to obtain sections with relatively little bone compression, excellent preservation of cellular elements, and a minimum of wrinkling. A wide variety of stains have been used for these sections and those reported here are Gill's hematoxylin-eosin, Nocht's azure-eosin, Feulgen, Hoechst 33258 (bisbenzimid H 33258), methyl green-pyronin, PAS, alizarin red, and von Kossa silver stain. There was excellent preservation of acid and alkaline phosphatase activities. A new method of prestaining immunofluorescent labeling was also applied to bone and examples of staining with anticollagen I and antifibronectin are presented.

Animals↗
PubMed1980

A novel method to improve immunofluorescence in histological specimens.

A new approach to immunofluorescent labeling of sectioned tissue is described. Small tissue fragments which have been fixed and rendered permeable are labeled with immune reagents by either the direct or indirect method, prior to embedding in glycol methacrylate (2-hydroxyethyl methacrylate) at 4 degrees. In this way, the well-known superiority of plastic embedding over paraffin embedding or cryo-sections can be used to compare cellular structure in tissues with that seen in cultured cells.

Animals↗
PubMed1980

Mucus-stimulating factor in tears.

Mechanisms responsible for regulation of tear film mucus are poorly understood. Humoral factors responsible for stimulation of mucus secretion can be studied in vitro by using the free-swimming urn cell, a normal component of the coelomic fluid of the marine invertebrate Sipunculus nudus. With this system, a tear mucus-stimulating factor was found in normal human tears but was markedly decreased in patients with dry eye syndromes. It is suggested that a mucus-stimulating factor exists in normal human tears and that a decrease in this substance may be instrumental in the pathophysiology of certain dry eye syndromes.

Animals↗
PubMed1979

Transfer of bacterial infections by donor cornea in penetrating keratoplasty.

A 45-year-old man died of Hogdkin's disease complicated by peritonitis and possible septicemia. His corneas were used for transplant in a 26-year-old man with advanced keratoconus and a 42-year-old man with vascularized central leukoma of old herpetic keratitis. Both recipients developed a fulminating endophthalmitis with Pseudomonas aeruginosa. We believe that the donor corneas, although clinically normal, were heavily infected, with signs of inflammation possibly suppressed by the Hodgkin's disease.

Adult↗
PubMed1979

Secretory immune system of rabbit ocular adnexa.

A distinct system of immunity in a variety of animals is located subjacent to epithelial surfaces and is typified by the predominance of immunoglobulin A (IgA) and secretory component (SC) in various external secretions, including tears. The present study examined normal rabbit lacrimal gland, conjunctiva, and cornea for the presence of immunoglobulin and SC. IgA-staining plasma cells predominated within lacrimal gland and conjunctival stroma, and SC was found in the epithelial cells of both these tissues but not within corneal epithelium. These observations are consistent with findings for other secretory sites in both rabbits and humans and establish lacrimal gland and conjunctiva as integral parts of the rabbit secretory immune system.

Animals↗
PubMed1978

Nonspecific signals for B-cell localization and activation.

Virgin, inactive mammary gland autografted to the anterior chamber of the rabbit eye remains free of lymphoid cells. Activation of the ectopic gland by systemic injection of chorionic gonadotropin results in maturation of the gland and milk production, accompanied by the immirgration of lymphocytes and their activati-n to Ig formation, predominantly of the IgA class. In the presence of antigen-induced intraocular inflammation, the activated gland is able to influence the Ig class of B cells in the neighboring ocular tissues. These data suggest that even nonlymphoid tissues may elaborate lymphocyte-homing and polyclonal B-cell activating factors which function independently of specific antigen.

Animals↗
PubMed1978

Small angle x-ray scattering studies on adenovirus type 2 hexon.

Adenovirus type 2 hexons have been studied in solution by small angle X-ray scattering, and the following molecular parameters determined: radius of gyration (Rg) = 4.9 nm, molecular weight (M) = 310.000, invariant volume (Vinv) = 630 mn3, maximal distance (Dmax) = 14.5--15.5 nm. A diffraction pattern was obtained up to an angular increment of h = 2.5 nm-1. Various models for the hexon have been explored by calculating the diffraction pattern from the Debye formula for 1200 spheres arranged to define the scattering volume of each model. Models were first built according to electron micrographic results. Later, preliminary results of a crystallographic study were used for model building. The experimental pattern and the pattern resulting from the model determined by crystallographic methods were compared and showed good agreement.

Adenoviridae↗
PubMed1978

Structure and synthesis of a lipid-containing bacteriophage. Dissociation of bacteriophage PM2 into its morphological subunits.

The lipid-containing bacteriophage PM2 was dissociated stepwise in 1 M NcCl (pH 7.2)with increasing urea concentrations. In 2 M urea the following substructures could be identified: (a) a nucleocapsid containing all of the viral lipid, the DNA, proteins III and IV, plus a fraction of protein II, and (b) a second substructure respresenting particles which contained all viral elements except protein I, the spike protein. In 4 M urea the viral nucleocapsid containing all of proteins III and IV, the DNA, plus a fraction of protein II, was isolated. Upon increasing the urea concentration further, this nucleocapsid is stable up to 8.5 M urea; in 9 M urea protein III was partly dissociated from the nucleocapsid. The nucleocapsid in 4--8.5 M urea is stabilized by the addition of 0.1--3 M NaCl but dissociates if the NaCl concentration is less than 0.1 M. The nucleocapsid was also dissociated in 4--8.5 M urea at pH 4.5. The nucleocapsid structures and some intermediate morphological subunits have been analysed by physical methods, enabling us to draw some conclusions about the structure and hydration of the virus.

Amino Acids↗
PubMed1978

Structure and synthesis of a lipid-containing bacteriophage. Total reconstitution of bacteriophage PM2 in vitro.

The lipid-containing bacteriophage PM2 was reconstituted stepwise from its purified denatured subunits. In the first step the nucleocapsid was reconstituted from the DNA and the two nucleocapsid proteins. Slight biochemical differences between reconstituted nucleocapsids and those isolated from native virus were seen. Combination of reconstituted nucleocapsid or nucleocapsid from virions with the coat and spike proteins in the presence of the viral lipids resulted in the formation of infectious virus in both cases. The reconstituted particles contained amounts of viral components similar to those in native virus, except for the lipid content. The amount of lipids present in the reconstituted particles was twice as high as the lipid content of native bacteriophage.

Bacteriophages↗
PubMed1977

Structure and synthesis of a lipid-containing bacteriophage. An endolysin activity associated with bacteriophage PM2.

Endolysin was induced in Pseudomonas BAL-31 infected with bacteriophage PM2 and was also associated with the purified virion. This enzyme required divalent cations for its activity, Ca2+ being the most effective cation. Endolysin activity in the virion increased up to three-fold upon disruption and the activity could be localized in the viral nucleocapsid. Thus the enzyme is localized within the virion. After purification of the structural proteins of bacteriophage PM2, only the nucleocapsid protein (III) had endolysin activity.

Bacteriolysis↗
PubMed1977

Structure and synthesis of a lipid-containing bacteriophage. Effects of lipids containing cis or trans fatty acids on the reconstitution of bacteriophage PM2.

Infectious PM2 virus paticles could be reconstituted in vitro from a mixture of nucleocapsid, phospholipids containing cis fatty acids, and proteins I and II. The presence or absence of acyl phosphatidylglycerol, a minor lipid component of thevirion, did not affect the reconstitution of infectious particles, even though it was incorporated into the particles when present. When phosphatidylglycerol was completely replaced by acyl phosphatidylglycerol in the reconstitution mixture, no infections particles were formed. Lipids containing either cis or trans fatty acids were also used for reconstitution in vitro of the lipid-containing bacteriophage PM2. Regardless of the ratio of phosphatidlyglycerol to phospatidylethanolamine in the reconstitution mixture, infectious particles were formed and had almost the same phospholipid composition when lipids containing cis-palmitoleic acid were used; no infectious particles were obtained when lipids containing trans-palmitoleic acid were used. In the latter case, virus-like particles were, however, formed. Reconstituted particles containing cis fatty acids were infectious when tested on wild type Pseudomonas BAL-31 as well as on the unsaturated fatty acid auxotroph grown in the presence of either cis or trans-palmitoleic acid. Reconstituted particles containing trans fatty acids were not infectious on any of these cells. When trans fatty acids as well as cis fatty acids were present in the reconstitution mixture, then there was a lower yield of infectious particles. Particles with either cis or trans fatty acids had all four viral proteins and adsorbed to BAL-31 host cells in a specific manner.

Bacteriophages↗
PubMed1977

Chemical and physical properties of mycobacteriophage D29.

Mycobacteriophage D29 has a head of uniform size (average diameter 65 nm) and regular shape and a tail of variable length. The stability of the bacteriophage is optimal between pH 9 and 10. The virus contain double-stranded DNA and six structural polypeptides, three major and three minor. The molecular weights of these six polypeptides, as determined by polyacrylamide gel electrophoresis in the presence of dodecylsulfate, are 150 000, 138 000, 13 000, 66 000 and 24 000. The virus contains no lipids as shown by (a) the lack of structural changes after inactivation of the bacteriophage with chloroform, (b) the absence of lipids containing [32P]phosphate or [35S]sulfate in labeled virus, and (c) the absence of an electron paramagnetic resonance spectrum in bacteriophage which had been incubated with a nitroxide-containing fatty acid.

DNA, Viral↗
PubMed1977

Conjuctivitis and keratoconjunctivitis associated with primary immunodeficiency diseases.

Nineteen patients with a variety of well-defined primary immunodeficiency diseases were examined for ocular abnormalities. Eight patients with low levels, or absence, of all the major serum immunoglobulins had conjunctivitis or keratoconjunctivitis associated with bacterial infection. The remaining 11 patients, who had at least one immunoglobulin class present in normal concentration in the serum, showed no inflammatory ocular lesion. Absence of only IgA, the major tear immunoglobulin, did not predispose the eye to these lesions.

Adolescent↗