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Biomedical subjects

B Mansa

Publications and source records attributed to B Mansa.

14 recordsLinked to original sources
PubMed1992

Determination of IgG subclass antibodies to Pseudomonas aeruginosa outer membrane proteins in cystic fibrosis lung infection using immunoblotting and enzyme-linked immunosorbent assay.

IgG subclass antibodies to Pseudomonas aeruginosa outer membrane proteins (OMP) were investigated in serum from cystic fibrosis (CF) patients by immunoblotting and enzyme-linked immunosorbent assay (ELISA). Fifteen patients (eight in good and seven in poor clinical condition) have been followed for an average of 13 years with multiple serum samples covering the preinfection, and early and late stages of chronic infection. Laser-scanning densitometry of photographs taken from immunoblots was used to quantify antibody level and compare with ELISA titres. The earliest anti-OMP antibodies to appear were of the IgG1 subclass. There was no significant difference in IgG subclass antibody levels to OMPs between patients in relatively good and poor clinical condition. Data presented indicate a high positive correlation among measurements of IgG subclass antibodies to P. aeruginosa OMPs using ELISA and immunoblotting.

Antibodies, Bacterial↗
PubMed1992

Polyacrylamide gel electrophoresis analysis of lipopolysaccharide from Pseudomonas aeruginosa growing planktonically and as biofilm.

Lipopolysaccharide (LPS, endotoxin) was extracted from biofilm and planktonically grown monoagglutinable (1118) and polyagglutinable (258 and 15703) strains of Pseudomonas aeruginosa isolated from cystic fibrosis patients with chronic pulmonary infections. Analysis by polyacrylamide gel electrophoresis (PAGE) followed by immune-detection of LPS fractions showed an S-form appearance of strain 1118 and 258 with three distinct clusters of high molecular weight bands, whereas 15703 appeared semi-rough. LPS of semi-rough cells grown planktonically and as biofilm showed a very similar PAGE pattern; however, the core/lipid A R-LPS fraction was more prominent in biofilm-LPS than in planktonic-LPS extracted from the S-form bacteria (1118 and 258). The apparent change in LPS sub-unit components of the bacteria when grown as biofilm may reflect changes in the outer membrane structure that contribute to the altered physico-chemical properties of biofilm bacteria in foreign-device associated infections and chronic P. aeruginosa lung infection in cystic fibrosis patients.

Bacteriological Techniques↗
PubMed1992

Screening method for beta-lactamase substrate profiles.

A disc diffusion method, based on the idea of Klundert, for screening of substrate profiles of beta-lactamases was developed in order to perform epidemiological studies. The method was tested against 30 different reference beta-lactamases and 59 clinical isolates known to produce TEM-1, SHV-1 and BRO-1. The reproducibility and discriminating power of the disc diffusion method made it possible to differentiate between eight types of substrate profiles for the 30 reference beta-lactamases and to differentiate between TEM-1, SHV-1 and BRO-1 from clinical isolates. In combination with analytical isoelectric focusing the disc diffusion method gives a reliable identification of beta-lactamases.

Anti-Bacterial Agents↗
PubMed1992

beta-lactamases in Shigella.

The occurrence of resistance and production of beta-lactamases was investigated in 60 Shigella strains. Ampicillin resistance was found in 28 (47%) of the isolates, the resistance being more frequent in Sh. flexneri than in Sh. sonnei. All strains were susceptible to cefotaxime, mecillinam, and ciprofloxacin. The beta-lactamases produced by Shigella were similar to TEM-1, OXA-1, or the low-level chromosomally mediated cephalosporinase produced by Escherichia coli. The beta-lactamases produced by Sh. flexneri were most often the OXA-1-like enzymes.

Anti-Bacterial Agents↗
PubMed1991

Immune dysfunction in multiple myeloma. Reduced natural killer cell activity and increased levels of soluble interleukin-2 receptors.

Multiple myeloma (MM) is characterized by an increased susceptibility to infections and to other malignancies. Selected related immune functions were studied. Spontaneous and interleukin-2-stimulated natural killer (NK) cell activities were normal in 19 patients with MM compared with 62 controls. In contrast, interferon-stimulated NK cells had a significantly lower increase in activity in MM than in controls. The normal improvement in lytic NK cell activity after addition of indomethacin to the mononuclear cell cultures (to inhibit prostaglandin-mediated suppression) was not observed in cultures from MM patients. As reported for other lymphoproliferative disorders, the levels of soluble interleukin-2 receptors in serum were significantly higher in MM (600 U/ml median value) compared with controls (317 U/ml median value), P less than 0.0001, and the concentration of interleukin-2 receptors was significantly correlated with the concentration of monoclonal immunoglobulin in serum. Blood monocyte chemotactic responsiveness was significantly lower in MM patients with both zymosan-activated serum and f-Met-Leu-Phe as cytotaxins, suggesting reduced ability to accumulate at inflammatory foci. In contrast, release of reactive oxygen radicals, believed to be associated with the killing ability of monocytes, was normal after in vitro stimulation.

Aged↗
PubMed1991

Morphology of Pseudomonas aeruginosa phages from the sputum of cystic fibrosis patients and from the phage typing set. An electron microscopy study.

Sixteen phage suspensions isolated from the sputum of sixteen cystic fibrosis patients and five phages from the present phage typing set were studied by electron microscopy. All sputum samples contained at least one type of bacteriophage (range: 1-4) which could be classified by the morphology and dimensions of the virion. All phages isolated from sputum as well as the four typing phages were tailed phages. The clinical phages belonged either to the Myoviridae, Siphoviridae or Podoviridae family. The four typing phages belonged to the Myoviridae family. The detection of the presence of tailed phages in sputum further supports the prevailing theory that phages play a role in the phenotypical change of Pseudomonas aeruginosa during the chronic lung infection of cystic fibrosis patients, since only tailed phages are known to be temporate and thus mediate transduction and conversion.

Bacteriophage Typing↗
PubMed1990

The effect of ranitidine on cellular immunity in patients with multiple myeloma.

Multiple myeloma is characterized by an increased susceptibility to infections and to other malignancies. In a double-blind, placebo-controlled study the potential impact of immunomodulation by ranitidine was studied in 20 patients with multiple myeloma. Three patients were untreated, while 17 after previous cytotoxic therapy were in a stable phase of their disease. All were without clinical signs of infections and at that time had not been treated with other immunomodulating agents. The patients were randomized to oral ranitidine 300 mg twice a day for 21 days or placebo, and several immunological parameters related to multiple myeloma were studied. The blood monocyte chemotactic response was improved in patients treated with ranitidine, and superoxide anion production increased from 2.02 nmol/min to 3.86 nmol/min (median values), while it was unchanged in patients given placebo (2.19-2.25 nmol/min) (P less than 0.005 between groups). Among ranitidine-treated patients spontaneous NK cell activity was unchanged, while in vitro interleukin-2- and interferon-alpha-stimulated NK cell activity decreased (P less than 0.03, respectively). As production of oxygen radicals constitutes an important mechanism of monocyte killing activity against microorganisms and probably against malignant cells, it is suggested that ranitidine may be of beneficial impact in the treatment of multiple myeloma.

Adjuvants, Immunologic↗
PubMed1990

In vitro cytotoxic effect of alpha-hemolytic Escherichia coli on human blood granulocytes. Inhibition by alpha-hemolysin antibody.

The influence of alpha-hemolysin antibody on the in vitro cytotoxic effect of alpha-hemolytic Escherichia coli bacteria and culture filtrates was investigated. Damage to human blood granulocytes was quantified by measuring the release of chromium 51 from labelled cells in the presence of whole or fractionated plasma containing alpha-hemolysin antibody. Anti-alpha-hemolysin activity was found exclusively in the IgG fraction of plasma. Human plasma contained "natural" alpha-hemolysin antibody to various titers. Vaccination of rabbits resulted in only modest rises in alpha-hemolysin antibody titers. The cytotoxic effect of alpha-hemolytic E. coli bacteria as well as that of bacterial culture filtrates was reduced in a titer-dependent way in the presence of plasma containing alpha-hemolysin antibody. These results indicate that the cytotoxic effect of alpha-hemolytic E. coli is inhibited by alpha-hemolysin antibody.

Adult↗
PubMed1990

Intravenous immunoglobulin: a single-blind trial in children with Lennox-Gastaut syndrome.

The antiepileptic effect of intravenous immunoglobulin (Sandoglobulin, Sandoz) was investigated in Lennox-Gastaut syndrome by an add-on, placebo-controlled, single-blind trial. Ten patients, aged 4-14 years, with insufficient response to conventional anticonvulsive therapy received placebo and Sandoglobulin 400 mg/kg two times each with an interval of two weeks. The washout period was four weeks and the total observation period 14 weeks, during which parents daily registered number and type of seizures. EEG, in vitro lymphocyte transformation tests and concentrations of immunoglobulins including IgG subclasses were evaluated before and after active treatment. Two children showed an immediate reduction in their high-frequency and invariable seizure activity from 42% to 100% and a less abnormal EEG. In addition, general well-being and intellectual performance was improved. The strongest response was observed in one child with a concomitant finding of a low level of IgG2, the only abnormal immunologic test in this study. The remaining 8 children, who had either a high or a low but variable seizure frequency showed no immediate change as EEG and their general condition was unaffected. We conclude that intravenous immunoglobulin had an immediate and pronounced effect on break-through seizure activity and a simultaneous neurophysiologic effect in 20% of our patients with Lennox-Gastaut syndrome. The effect was not confined to patients with immunologic abnormalities.

Adolescent↗
PubMed1990

Complement and immunoglobulin studies in 15 cases of chronic meningococcemia: properdin deficiency and hypoimmunoglobulinemia.

The purpose of this study was to investigate whether patients with chronic meningococcemia have abnormalities in their humoral immune system. The alternative and classical complement system, the levels of IgA, IgG and IgM, as well as IgG subclasses were studied in 15 individuals who had recovered from chronic meningococcemia. We found one individual with complete deficiency of properdin, a component of the alternative complement pathway. In the other patients, the complement system was normal. The mean plasma IgG concentration was significantly below normal in the patient group, while the mean values of IgA, IgM and the IgG subclasses were normal. Two individuals, however, had low IgG2 and IgG4 levels. We conclude that properdin deficiency and reduced plasma IgG levels may predispose to chronic meningococcal disease, but that the majority of patients with chronic meningococcemia have a normal humoral immune system.

Adolescent↗
PubMed1990

Studies on beta-lactamases from Escherichia coli isolated from urinary tract infections.

The beta-lactamase types present in 75 ampicillin and carbenicillin resistant E. coli were characterized using isoelectric focusing (IEF). The strains were isolated from patients with urinary tract infections from two geographically different areas of Denmark: 38 strains from Copenhagen and 37 strains from North Jutland. For 19 of the strains from Copenhagen and 18 of the strains from North Jutland, their beta-lactamase activity against nitrocefin and ampicillin, carbenicillin, benzylpenicillin, cloxacillin and cephaloridine was examined by a micro-iodometric and an UV-spectrophotometric assay. The strains from Copenhagen showed greater activity (p less than 0.001) against nitrocefin than the strains from North Jutland. The rate of hydrolysis of ampicillin was greater for the strains from Copenhagen than for the strains from North Jutland. Ninety-three per cent of the strains produced plasmid-mediated beta-lactamases, of which the most prevalent, TEM-1, was produced by 97 per cent of these strains, and OXA-1 by 3 per cent.

Anti-Bacterial Agents↗
PubMed1976

A study of Russell bodies in human monoclonal plasma cells by means of immunofluorescence and electron microscopy.

Five patients with a serum M component were shown to possess plasma cells containing Russell bodies. Four of the patients suffered from multiple myeloma, whereas the fifth probably had a different disease or was in a premyeloma stage. The Russell bodies stained blue with the May-Grünwald-Giemsa stain and were found both in the nuclei and in the cytoplasm of the plasma cells. Ultrastructural studies showed that the Russell bodies were osmophilic and those located in the cytoplasm were always situated within the cisternae of the rough endoplasmic reticulum. The intranuclear Russell bodies were always surrounded by a triple layered membrane, and some evidence was obtained that these bodies were first formed within the perinuclear space of the cells. Immunofluorescence studies using anti-L chain conjugates showed a positive marginate straining of the intranuclear as well as the cytoplasmic Russell bodies of the cells from all patients. Only one patient had cells with Russell bodies which also stained their location in the plasma cells. It is concluded that some plasma cells in multiple myeloma may produce an excessive amount of L chains which, in combination with a failure in the secretion of immunoglobulin molecules, may lead to the formation of Russell bodies.

Adult↗
PubMed1976

Streptococcal bacteriophage 12/12-borne hyaluronidase and its characterization as a lyase (EC 4.2.99.1) by means of streptococcal hyaluronic acid and purified bacteriophage suspensions.

Hyaluronic acid was obtained from filtrates of heat-killed cultures of Streptococcus pyogenes group A, strain K56, by simple ethanol precipitation and treatment with an adsorbent. The hyaluronic acid is pure as judged from chemical and sedimentation analyses. Particles of streptococcal bacteriophage 12/12 were isolated from phage-lysed group A streptococci by polyethylene glycol precipitation and isopyenic centrifugation. Electron micrographs of negatively stained preparations showed a typical Bradley group B virus with a long, flexible, cross-striated tail and a knob- or star-like structure at the distal tip of the tail. The hyaluronic acid is depolymerized upon incubation with the phage 12/12 virions. After extensive digestion, a mixture of at least four oligosaccharides is formed, the two smallest of which are a tetra- and octasaccharide terminating in reducing N-acetyl-D-glucosamine. The tetrasaccharide shows an absorption maximum at 231.5 nm with a molar extinction coefficient epsilon = 4820 litres X mole-1 X cm-1, and it is therefore concluded that the bacteriophage-borne hyaluronidase catalyses a beta-elimination. Accordingly it is classified as a hyaluronate lyase (EC 4.2.99.1).

Bacteriophages↗