Search PubMed⌕ Search

Biomedical subjects

M S Collins

Publications and source records attributed to M S Collins.

At least 91 records · Page 5Linked to original sources
PubMed1979

Antigenic and structural relationships between avian paramyxoviruses isolated from ducks in Hong Kong and Mississippi, U.S.A.

Representative isolates of the paramyxoviruses duck/Hong Kong/75 and duck/Mississippi/75 were shown to be serologically closely related by haemagglutination and neuraminidase inhibition tests. The structural polypeptides of these viruses were also shown to be similar. For each of the isolates tested, polyacrylamide gel electrophoresis in the presence of SDS revealed a similar polypeptide pattern consisting, under reducing conditions, of seven polypeptides with apparent mol. wt. ranging from 46000 to 190000. Each virus had two glycosylated polypeptides with apparent mol. wt. of 56000 and 71000 to 72000 under reducing conditions and 62000 to 63000 and 135000 to 142000 under non-reducing conditions.

Animals↗
PubMed1979

Development of resistance to amphotericin B in Candida lusitaniae infecting a human.

Candida lusitaniae associated with infection in a patient with acute myelogenous leukemia developed resistance to amphotericin B during systemic treatment of the patient. The organism, when isolated initially, was inhibited by 0.31 mug of amphotericin B per ml in yeast nitrogen base agar, but when isolated (20 days later) just antemortem and postmortem, required 100 and 50 mug/ml, respectively, for complete inhibition at 48 h.

Amphotericin B↗
PubMed1979

Immunization of mice against coccidioidomycosis with a subcellular vaccine.

In vitro-cultivated spherules of Coccidioides immitis were disrupted in a Braun homogenizer. The resultant wall fragments were separated from cell sap and endospores by centrifugation. Extraction of the walls with phosphate-buffered saline yielded a subcellular fraction that was immunogenic in mice. This fraction, which contained polysaccharide and protein, gave substantial protection against intranasal challenge with a usually lethal dose (1,000) of arthrospores, provided that it was administered with adjuvant.

Adjuvants, Immunologic↗
PubMed1977

Uniform susceptibility of various strains of Coccidioides immitis to amphotericin B.

The susceptibility of 12 strains of Coccidioides immitis to amphotericin B (amB) was studied in vitro and in vivo. The minimal inhibitory concentration (MIC) of the mycelial phase of these strains was 0.078 to 0.16 mug/ml after 3 days of incubation, but by 15 days all strains were inhibited by 2.5 mug/ml. Mice infected intraperitoneally with these strains were sucessfully treated with 0.5 mg of amB per kg per day. These strains included several studied by others and which reportedly varied widely in susceptibility (MIC from 0.24 to 24.01 mug/ml) to amB. Four of these strains representing this putative broad range of susceptibility were used to infect mice intranasally. Regardless of infecting strain, mice were sucessfully treated with 0.38, 0.75, and 1.5 mg/kg, but 0.19 mg/kg was only partially effective. Thus, in vivo as well as in vitro there was a uniform response of C. immitis strains to amB.

Amphotericin B↗
PubMed1977

The purification and polypeptide composition of avian infectious bronchitis virus.

Purification of egg-grown infectious bronchitis virus (IBV) by sucrose density gradient centrifugation alone, or sucrose density gradient centrifugation plus pH 8.0 treatment, concanavalin A precipitation or metrizamide density gradient centrifugation, failed to produce any differences in the virus polypeptide pattern following polyacrylamide gel electrophoresis in the presence of SDS(SDS-PAGE). SDS-PAGE of purified IBV on 7.5% acrylamide gels separated 16 polypeptides which were detectable by staining with Coomassie blue or measurement of radioactivity following electrophoresis of (3H)-leucine labelled IBV. The molecular weights of the polypeptides were within the range 15,000-135,000. The polypeptides of egg and chick kidney (CK) cell-grown IBV were identical in both size and number but quantitative differences were detected. In particular the relative proportion of the major 52,000 molecular weight polypeptide was greatly reduced in IBV grown in CK cells. SDS-PAGE of purified IBV and staining with Schiff's reagent to detect carbohydrate revealed four.bands with molecular weights of 128,000, 86,000, 67,500 and 37,000. The 128,000 band did not correspond to any of the detected polypeptides. Use of 5% acrylamide gels for SDS-PAGE of IBV failed to resolve all the minor polypeptides and only seven bands were detected.

Centrifugation, Density Gradient↗
PubMed1977

Cutaneous infection in man caused by Fusarium moniliforme.

Fusarium moniliforme was isolated from a pustular lesion on the hand of an otherwise healthy male. Branching hyphae were seen in pus stained by the periodic acid-Schiff method. Pustular lesions containing branching hyphae were produced in mice after subcutaneous injection of microconidia. The experimental infection in mice and the naturally occurring lesion in man healed without treatment in 1 to 2 weeks. Although production of catenulate microconida was abundant on several common laboratory media, the characteristic macroconidia of F. moniliforme were produced only on barley-pea-rice straw agar.

Adult↗
PubMed1976

Heterogeneity of infectious bronchitis virus grown in eggs.

Egg-grown infectious bronchitis virus, strain Beaudette, was concentrated and centrifuged on sucrose density gradients to separate the virus into five peaks with densities of 1.144, 1.160, 1.172, 1.191 and 1.218 g/cm3. All peaks retained infectivity, complement fixation activity and were labelled with 3H-uridine. Morphologically the densest peak consisted of very large virus particles and amorphous material, the other peaks consisted of mainly intact particles although small differences in size and pleomorphism were seen. Polyacrylamide gel electrophoresis of material from the density gradient peaks revealed four major polypeptides and at least 10 minor polypeptides. The proportions of the polypeptides were approximately similar for all peaks with the exception of the densest peak in which the major polypeptides were greatly reduced. The four major polypeptides had approximate molecular weights of 1. 52,000, 2. 45,000, 3. 34,000, 4. 32,000. The major polypeptides 1 and 4 were shown to be glycosylated as were two of the minor polypeptides.

Animals↗
PubMed1976

Treatment of murine coccidioidomycosis with polymyxin B.

An agar dilution method was employed to test the susceptibility of 12 strains of Coccidioides immitis to polymyxin B (PB). After 3 days of incubation, eight strains were markedly inhibited by 5.0 mug of PB per ml and four strains did not grow. PB at 10 mug/ml inhibited the growth of all strains through 20 days of incubation. To determine whether PB has anticoccidioidal activity in vivo, mice in groups of 30 were infected intraperitoneally with a mean lethal dose (LD(50)) or 20 LD(50) of arthrospores of C. immitis ATCC 28868 (Silveira). Treatment by intraperitoneal injection of PB (2.5 mg/kg) was begun 2 or 5 days after challenge. By 40 days after infection, 47 and 7% of the untreated mice challenged with an LD(50), respectively, were alive. Of mice infected with an LD(50) or 20 LD(50) and treated with PB beginning 2 days after the challenge, 90% of each group were alive by day 40. Initiation of PB therapy 5 days after infection permitted survival of 84% of the mice infected with an LD(50); however, only 27% of the mice infected with 20 LD(50) survived by day 40. In this latter group there was evidence that PB prolonged life since 56% of the treated mice were alive by day 15 as compared with 30% of the controls. PB in vivo was fungistatic since the majority of treated mice had C. immitis in the liver, lungs, and spleen.

Animals↗
PubMed1976

Effect of amphotericin B and rifampin against Coccidioides immitis in vitro and in vivo.

Amphotericin B, the principal drug used for treating systemic mycoses, possesses undesirable toxic properties. The ability of this antibiotic to potentiate antifungal activity of other compounds suggests that lower doses of amphotericin B could be used in combination with a second drug without loss of therapeutic efficacy. In vitro tests demonstrated that amphotericin B potentiated rifampin against the mycelial growth phase of Coccidioides immitis but not against the spherule-endospore phase. Therapy for murine coccidioidomycosis with a combined amphotericin B-rifampin regimen was not better than treatment with amphotericin B alone; in fact, combined drugs may have been even less effective. This would have clinical significance for therapy of concurrent infections.

Amphotericin B↗
PubMed1975

Effect of pH on the growth and cytopathogenicity of avian infectious bronchitis virus in chick kidney cells.

The growth of avian infectious bronchitis virus (IBV) in chick kidney cells at different pH values in the range 6.0-9.0 demonstrated that although the virus was released at a much faster rate at the higher pH values the titre tended to drop more quickly. At the acid pH values the virus was released more slowly but reached a maximum titre similar to that at the higher pH values and showed only minimum reduction in infectivity up to 49 hours post inoculation. The stability of virus in tissue culture medium was shown to be directly related to pH 6.0-8.0, being more stable at the acid pH values. The degree of cytopathogenicity induced in chick kidney cells following infection with IBV was directly related to the pH at which the cells were incubated, occurring earlier and more extensively in cells at the higher pH values. Cell macromolecule synthesis in chick kidney cells was inhibited following infection with IBV and was apparently due to cell damage and death.

Animals↗
PubMed1975

Inhibition of growth of Coccidioides immitis on Sabouraud medium containing polymyxin B.

No growth of Coccidioides immitis occurred when fluid from infected tissue or arthrospores suspended in distilled water were plated on the surface of Sabouraud medium, solidified with refined agar, and containing 20 mg of polymyxin B per liter. Solidification of Sabouraud medium with unrefined agar completely abolished the anticoccidioidal activity of polymyxin B.

Agar↗
PubMed1974

Inhibition by lysozyme of growth of the spherule phase of Coccidioides immitis in vitro.

Development of mature endosporulating spherules from an endospore inoculum was markedly inhibited by human or hen egg-white (HEW) lysozyme at 5 mug/ml. Mature spherules formed in medium containing 5 mug per lysozyme per ml (3.3 x 10(-7) M) were approximately 50% smaller than control spherules. In addition, lysozyme induced a large portion of the endospore inoculum to revert to the mycelial growth phase. Increasing lysozyme concentrations to 10 or 20 mug/ml prompted a nearly complete reversion of the inoculum to the mycelial phase. Mature endosporulating spherules removed from growth medium and resuspended in a solution of human or HEW lysozyme at 18 mug/ml in distilled water prompted leakage of four to five times as much of materials absorbing maximally at 260 nm into the supernatant as untreated control spherules during 90 min of incubation. This four- to fivefold increase in nucleotide loss was evident at 4, 25, and 37 C. The permeability of 1-day-old immature spherules and 8-day-old endospores was considerably altered by lysozyme treatment of cells suspended in distilled water. Large amounts of potassium and nucleotides were rapidly lost by each type of cell when treated with 20 mug of lysozyme per ml. After 270 min of exposure to lysozyme, 98% of the immature spherules and 25% of the endospores were nonviable. Lysozyme adsorption by formalin-killed spherules in the presence of varying concentrations of calcium ion and the rapid alteration of permeability seen after lysozyme treatment suggested that the cell membrane was damaged as a result of binding lysozyme.

Animals↗
PubMedDate not supplied

[Prevention of gram-negative and gram-positive infections using 3 intravenous immunoglobulin preparations and therapy of experimental polymicrobial burn infection using intravenous Pseudomonas immunoglobulin G and ciprofloxacin in an animal model].

Three immunoglobulin preparations for intravenous infusion were compared in vivo to determine their relative protective capacity against several gram-negative and gram-positive pathogens. Polyglobin N is a conventional IgG concentrate. Psomaglobin N is identical in formulation to Polyglobin N but is prepared from the plasma of donors who have naturally high levels of antibody to lipopolysaccharide antigens of Pseudomonas aeruginosa. IgGMA is a conventional IgG concentrate containing 12% IgG and 16% IgA. In a murine model of burn wound sepsis the three IgG preparations were similarly protective against three or ten strains of P. aeruginosa. Psomaglobin N and Polyglobin N were significantly (p less than or equal to 0.015) more protective than IgG-MA against six of ten and three of ten strains of P. aeruginosa, respectively. In a murine model of Streptococcus pneumoniae type 3 pneumonia, the three Ig preparations were similarly protective. IgG-MA was significantly more protective (p less than or equal to 0.025) than Psomaglobin N and Polyglobin N against Salmonella typhimurium in murine peritonitis. However, the mean protective dose (PD50) of the two later preparations was less than or equal to 20 mg/kg body weight. In models of peritonitis both Psomaglobin N and Polyglobin N were more protective than IgGMA (p less than or equal to 0.004) against Haemophilus influenzae b, Klebsiella pneumoniae, Serratia marcescens 06:H3 and group B Streptococcus types 1b and 1c. Psomaglobin N and ciprofloxacin were employed to treat established polymicrobial murine burn wound sepsis resulting from contamination of the burn site with mixtures of P. aeruginosa and Staphylococcus aureus. Psomaglobin N or albumin was given once 16 h after challenge.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Use of a new, low-pH immunoglobulin G preparation during episodes of bacteremia in the rat.

A rapidly expanding role for immunoglobulin G preparations in conditions other than the classical immunodeficiency syndromes is evident. This relatively new concept of treatment with polyclonal antibody has been tested in the rat with severe Salmonella typhimurium bacteremia with use of a newly developed, native immunoglobulin G preparation for intravenous use (IGIV pH 4.25). IGIV pH 4.25 increased survival time and decreased absolute mortality, prevented hypotension and acidosis, and ameliorated or prevented changes in variables indicative of organ damage during S. typhimurium bacteremia in the rat. Intravenous infusion of IGIV pH 4.25 at high rates did not cause further deterioration in the arterial blood pH in the acid-base-compromised rat and hence should not cause clinically significant decreases in pH in patients with compromised acid-base regulating systems.

Acidosis↗
PubMedDate not supplied

Immunoglobulin G: potentiation of tobramycin and azlocillin in the treatment of Pseudomonas aeruginosa sepsis in neutropenic mice and neutralization of exotoxin A in vivo.

Mice with cyclophosphamide-induced neutropenia were challenged with four immunotypes of Pseudomonas aeruginosa by contamination of a small dorsal surface wound. The infections were lethal; 100% of control animals (n = 80) treated only with albumin died. Administration of an immunoglobulin G intravenous preparation (IGIV) and/or therapy with tobramycin or azlocillin was begun 16 hr after challenge. Mortality among mice (n = 120) treated only with an antibiotic was 75.0%, while that among mice (n = 80) treated only with IGIV was 78.8%. Combination therapy with IGIV and an antibiotic (n = 120) resulted in mortality of 38.3%. The protection afforded by IGIV may have resulted in part from neutralization of exotoxin A, as mice treated with IGIV before challenge with exotoxin A were subject to lower mortality and had lower levels of serum aspartate and alanine aminotransferases than controls.

ADP Ribose Transferases↗